# PostHog vs Rollbar: A Hands-On Error Tracking Comparison for 2026

A release that did nothing but slow down one database query tripped up PostHog and Rollbar in exactly the same way. Each reported my months-old coupon bug as a brand-new error, because the slow query changed which framework frames sat under the crash, and both products count those frames when they group. The two tools disagreed on almost everything else.

**PostHog is a product analytics platform with error tracking built in,** next to session replay, logs, OpenTelemetry tracing and an AI assistant, all on one usage-based bill with a large free tier. Its error pages lean on those neighbors: a server error links to its trace, its logs and the user's recording.

Rollbar is a dedicated error tracker for the browser and the server. It skips performance and logs entirely and puts its effort into the release workflow: resolving in a version, naming the deploy that brought a bug back, and a page per version showing what changed.

[ad-logs]

I ran both on the same bookstore app, browser and server, through the same three releases, so this is a head-to-head throughout. Where I skipped a feature, like Rollbar's GitHub-based root cause analysis, the section says so.

What follows covers what each tool caught, how it explained it, how it grouped it, how it handled releases, and what it costs.

## PostHog vs Rollbar: Results at a glance

These results come from an Express and Vite app with each tool configured from its own documentation, PostHog on its free plan and Rollbar on a trial. Different stacks or custom fingerprint rules could move several rows.

| Area | Better in my test | Why |
|---|---|---|
| Setup | Tie | PostHog needed three defaults changed; Rollbar's new project showed tokens that didn't work |
| Error capture | **Rollbar**, narrowly | It caught the unhandled rejection PostHog missed |
| Source maps | **Rollbar** | Uploads tied to the version it reports, and function names recovered |
| Debugging an error | **PostHog** | Server source lines, a trace and its logs on the issue |
| Session replay | **PostHog** | Whole recordings; Rollbar keeps short clips around errors |
| Error grouping | Neither | Both split old and new bugs on framework frames in 1.2.0 |
| Releases and regressions | **Rollbar** | Resolve in a version, a suspected deploy, version pages |
| Performance | **PostHog** | Rollbar has no timing at all |
| Logs and querying | **PostHog** | A logs product and SQL; Rollbar has RQL over errors only |
| Alerts | Not compared | No alert was delivered from either |
| AI-assisted debugging | Not compared | Only PostHog AI ran; Rollbar's analysis wanted a GitHub link I skipped |
| Price | **PostHog** | 100,000 free exceptions against Rollbar's 5,000 |

## How I tested PostHog and Rollbar

monitoring-lab is my test bookstore, and its bugs are deliberate. Shoppers browse a Vite front end that calls an Express API on SQLite. Beside it, a stand-in price service fails on cue, and a report job runs every minute. Each tool connects through the same pair of adapter files, so the rest of the code never changes.

The failures each tool had to catch:

- **In the browser:** a `TypeError` from the wishlist button, an unhandled rejection from order tracking, and API calls that come back 404, 500 or 502.
- **In the API:** an unknown coupon crashing checkout, a missing book crashing its page, a handled out-of-stock error, 503s from the price service, and a recommendations promise nobody catches.
- **In the job:** failing sales report runs.

Two headless browser shoppers, alice and bob, sign in and shop. carol hits the API without a browser.

### The releases

| Release | What I checked |
|---|---|
| 1.0.0 | Install, first errors on both tiers, maps and replay |
| 1.1.0 | Whether the coupon bug, marked fixed, comes back flagged |
| 1.2.0 | Checkout's query turns slow, and one charge in five is rejected |

The interesting question in 1.2.0 is whether a tool tells you both things at once: checkout got slower, and something new is failing.

### SDKs and test limitations

| Platform | PostHog | Rollbar |
|---|---|---|
| Browser | `posthog-js` 1.441.0 | `rollbar` 4.1.0 from `rollbar/replay` |
| Node.js server | `posthog-node` 5.57.2 | `rollbar` with its Express error handler |
| Tracing and logs | OpenTelemetry to PostHog | ✘: not offered |
| Plan | Free plan, no card | Advanced trial |

- **Separate runs:** Rollbar on October 22, PostHog on October 28, both with the same traffic script. Counts aren't comparable one to one.
- **Rollbar's environments differ by tier:** my storefront reports "production" and my API "development", which affects some Rollbar views.
- **Untested AI:** Rollbar's root cause analysis needs its GitHub app, which I didn't install.
- **No alert delivery:** neither tool had a channel connected.

### Terms in each tool

| Concept | PostHog | Rollbar |
|---|---|---|
| A group of the same error | Issue | Item |
| One occurrence | Exception event | Occurrence |
| Fixed | Resolved | Resolved, optionally in a version |
| Silenced | Suppressed | Muted, or Snoozed for a time |
| Release | `$app_version`, or a source map release | `code_version`, plus reported deploys |
| Grouping override | Grouping rules | Custom fingerprinting |
| Trail before an error | Timeline, plus the trace | Telemetry |

## Setup and onboarding

Both tools cover the browser and the server from npm, in one project. Each new account had a problem that stopped data until I found it.

### PostHog: More products than you asked for, minus the one you need

PostHog asks for your goal first. "Find and fix issues" preselected product analytics, web analytics and session replay, and I had to add Error Tracking from the full list. Its AI install wizard doesn't list Express, so I followed the manual Node.js page:

![PostHog Node.js setup page](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/a79d44cb-2c7f-4b61-c49d-7581f7fd9700/lg2x =1512x747)

The marked note matters for every Express app: errors caught by Express need `setupExpressErrorHandler`, or they never reach PostHog. Then three defaults got in the way. Headless Chromium was filtered out until I set `opt_out_useragent_filter`, session replay was switched off at the project level, and my older `posthog-node` needed an upgrade.

### Rollbar: One SDK at a time, and a token to replace

Rollbar's picker shows one SDK's instructions at a time, so a full-stack app means a second trip through "Select different SDK":

![Rollbar onboarding SDK picker](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/9bd71525-7c65-4065-dc78-c0e40ffd5700/md1x =1126x736)

The brand-new project's setup pages handed me tokens belonging to an old, deleted project. Data only started flowing after I created fresh ones under **Project access tokens**. The browser setup with replay comes down to one client:

```javascript
[label web/src/monitoring/adapters/rollbar.js]
import Rollbar from 'rollbar/replay';

const rollbar = new Rollbar({
  accessToken: import.meta.env.VITE_ROLLBAR_CLIENT_TOKEN,
  captureUncaught: true,
  captureUnhandledRejections: true,
  payload: { client: { javascript: { code_version: '<your_release>' } } },
  [highlight]replay: { enabled: true, triggers: [{ type: 'occurrence', samplingRatio: 1.0 }] },[/highlight]
});
```

The highlighted trigger records a replay whenever an occurrence is reported. The Replays setup page suggested a 3.0 release candidate, and 4.1.0 worked fine.

> **Worth turning on:** in PostHog, switch on session recording and network capture in project settings on day one. In Rollbar, report deploys from your pipeline with the version, since suspected deploys and auto-resolve depend on them.

### Setup comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Both tiers in one project | ✔: one token | ✔: one project, two tokens |
| Express integration | ✔: error handler | ✔: error handler |
| Replay on after install | ✘: project switch needed | ✔: from the SDK config |
| Headless browsers | ✘: filtered by default | ✔: recorded |
| Problem on a new account | Error Tracking not preselected | Setup pages showed dead tokens |

**Verdict: Tie.** Each lost me time in a different way, and neither problem would recur once fixed. PostHog fits teams that want more than errors from one install, and Rollbar fits teams that want error tracking and replay with nothing extra to configure.

## Error capture

Both tools put the browser and the server into a single list. The difference was in what slipped through and how each row described itself.

### PostHog: Severity and owner on every row

PostHog's issues list puts occurrences, sessions and users on each row, with status, severity and assignee editable in place:

![PostHog issues list with severity and assignee](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/5a80922f-9a06-4f48-3d0b-9b63d901a400/md2x =1512x803)

Severity was set automatically on some rows. One failure never showed up: the rejected recommendations promise. The app has its own listener for unhandled rejections, and in Node's default mode the PostHog SDK relies on the process crashing to see them. Two smaller oddities were the report job's location naming my adapter's span wrapper, and anonymous requests counting as a new user each time.

### Rollbar: Every failure, but level only

After the first run, Rollbar's items list held 11 rows, six from the API and five from the storefront:

![Rollbar items list with API and browser errors](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/85fb52e2-3b18-41fc-974c-674368a0bc00/md1x =1126x736)

The recommendations rejection is there as item #3, and browser rows carry a replay icon. Rollbar shows a level on each item, with no handled or unhandled marker, so the handled out-of-stock error sits at the same weight as the crashes. Because my two tiers report different environments, the list and the People page treat them as separate halves of one app.

### Error capture comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Uncaught browser errors | ✔: captured | ✔: captured |
| Errors Express catches | ✔: through its handler | ✔: through its handler |
| Rejection with an app listener | ✘: missed | ✔: captured |
| Background job errors | ✔: wrong location | ✔: captured |
| Severity on the row | ✔: editable, some set automatically | Level only |
| Assignee on the row | ✔: inline | ✔: on the item |

**Verdict: Rollbar, narrowly.** It caught every failure I planted, the rejection included. PostHog's rows are more useful for triage, and a team without its own rejection handler might never hit the gap. Rollbar fits teams that want nothing missed, and PostHog fits teams that triage by severity.

## Source maps

Both tools needed uploads, since my storefront ran on a private host.

### PostHog: Two CLI steps, and a release you didn't name

`posthog-cli sourcemap inject` writes IDs into the bundle, and `sourcemap upload` sends the maps. Afterwards the wishlist crash resolved to `src/pages.js`, but its earlier events stayed in a separate issue:

![PostHog wishlist crash split into a minified and a mapped issue](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/b84ac144-6f76-464e-720f-6df1e08d9d00/lg1x =1512x803)

One bug now had two rows, because the fingerprint uses the resolved frames. The release attached to those maps was my git commit, since the inject step picks it from git unless you give it the release flags too.

### Rollbar: Upload per version, and a function name

Rollbar takes maps through its API, keyed by the `code_version` the SDK reports, and a short script handled it per release. Here's how the wishlist crash looked afterwards:

![Rollbar wishlist crash with source maps and replay](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/377d62e4-bb8f-4b76-5b7e-5f294b01c600/lg1x =1126x736)

Rollbar's top frame names the `bookDetail` function in `src/pages.js`, line 122, and the replay panel sits directly under the code. Rollbar recovered the function's name, and its maps belong to the version you report, with no git lookup involved.

### Source map comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Upload from a script | ✔: CLI, inject then upload | ✔: API per version |
| Release on the maps | Git commit unless set at inject | The `code_version` you send |
| Function names | ✘: anonymous handler | ✔: `bookDetail` |
| Errors before the upload | ✘: kept in a separate issue | Not tested |
| Server source lines | ✔: read from disk | ✘: not shown for Node.js |

**Verdict: Rollbar.** Its maps attached to the version I named and produced one row per bug. PostHog's server source lines are a real plus, and they belong to the next section.

## Debugging an error

The checkout crash from a bad coupon makes a fair test, since it starts in the browser and dies in the API.

### PostHog: The code, the request's trace, and its logs

The server issue shows lines 143 to 157 of `server.js` with line 150 marked, read from the server's own files:

![PostHog server issue with source lines](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/f0bca47b-8c6d-4e0b-173c-6d26b3b1cf00/md2x =1512x803)

**View trace** opens that request's spans, and its **Logs** tab narrows to the lines written during it:

![PostHog trace with its Logs tab](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/620905a8-24ee-4028-af0c-00b3c370a100/orig =1512x803)

Three log lines belong to this one checkout, with nothing from other shoppers. What's missing is the request body on the event, and anything from the browser, which you reach by session ID.

### Rollbar: Request values, a curl command and telemetry

Rollbar's **Detail** tab is built for server errors. It lists every request field and header with a **Typicality** column showing how often each value appears across occurrences, and it offers the request as a copyable curl command to replay it. Telemetry lists the last 100 console lines and HTTP calls.

On the server that telemetry belongs to the process, with no per-request scope. alice's payment error listed bob's and carol's activity too, so read it as what the server was busy with. The **Related** tab matches by title:

![Rollbar Related tab with similar titles](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/ed8f419c-ba9d-4666-9380-226cfb8bd300/lg2x =1126x736)

It lists other browser `ApiError` items, none of them the server crash behind the failed checkout. Rollbar has no tracing to join the two.

### Debugging comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Server source lines | ✔: from disk | ✘: file and line |
| The failing request's trace | ✔: View trace | ✘: not offered |
| Logs for one request | ✔: on the trace | ✘: process-wide telemetry |
| Request fields | Properties, no body | ✔: with Typicality |
| Re-send the request | ✘: not offered | ✔: curl command |
| Browser error to server error | Through the session ID | ✘: title matches only |

**Verdict: PostHog.** Code, trace and request-scoped logs on the issue explained the coupon crash fastest. Rollbar's Typicality and curl command are excellent for reproducing a server bug, and nothing in PostHog matches them. PostHog fits teams working across tiers, and Rollbar fits teams reproducing API failures by hand.

[summary]
<iframe width="100%" class="aspect-video h-auto" src="https://www.youtube.com/embed/7tQ7haFmSXI" title="Explore Traces | Better Stack" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

PostHog's trace stopped at the server's edge, and Rollbar could only suggest items with similar titles. My Better Stack test traced one storefront request across both tiers:

![Better Stack trace with browser and server spans](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/b980fb66-b9a0-438a-2be4-0225195d2300/public =1512x744)

The browser's 30 spans and the API's 7 share one trace. You go from the shopper's click to the failing server code without a session ID or a title search.

**[Trace one request through browser and API](https://betterstack.com/tracing)**
[/summary]

## Session replay

Both tools record users. PostHog records whole visits, and Rollbar records around errors.

### PostHog: Full recordings, once switched on

With recording enabled, an issue's **Recording** tab plays the visit at the moment the error fired:

![PostHog Recording tab at the wishlist crash](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/022ed6f3-7c8c-4128-0f61-8010cd893b00/lg1x =1512x803)

alice's cursor is on "Add to wishlist". Console and network timings were captured by default, and I added headers and bodies. Page text was visible at the default privacy level. PostHog also offers AI recording summaries and a highlights scanner, which I didn't try.

### Rollbar: Clips with linked items

Rollbar starts a recording when an occurrence fires and plays it inside the item. The event list beside the player is where it shines:

![Rollbar replay events with a linked item](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/16cae328-207c-4756-9b2a-9e1405605a00/orig =1126x736)

Network calls carry status and timing, clicks carry their CSS selector, and other Rollbar items from the same visit appear as links, like the order-tracking 404 here. My clips ran 0 to 15 seconds, and request bodies weren't part of them. Every account gets 1,000 replays a month.

> **Worth turning on:** in PostHog, raise the privacy level or mask sensitive elements before recording real customers.

### Replay comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| What's recorded | Whole sessions | Around occurrences |
| Length in my test | Full visits | 0 to 15 seconds |
| Network detail | ✔: bodies when enabled | Status and timing |
| Other errors in the visit | ✔: on the timeline | ✔: linked items |
| AI summaries | ✔: offered, not tested | ✘: not offered |
| Free allowance | 5,000 recordings a month | 1,000 replays a month |

**Verdict: PostHog.** A whole visit answers questions a 15-second clip can't reach. Rollbar's linked items are a clever touch, and its replay costs nothing extra at small scale.

## Error grouping

At 1.0.0, both tools grouped every bug correctly. 1.2.0 changed that for both, in nearly the same way.

### PostHog: Hidden frames still count

PostHog ignores message text, so charges for different amounts can share an issue. In 1.2.0, though, the new payment error landed in two issues:

![PostHog payment issue without vendor frames](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/07da79ab-5349-4f8e-33b7-185b21e97e00/lg1x =1512x747)

Both throw at `server.js:173`. The other issue's fingerprint also holds two `node:internal` timer frames, which the page hides yet still uses. The coupon crash and the out-of-stock error each gained two sibling issues the same way. PostHog's remedy is **Grouping rules**, empty by default, or merging through each issue's Fingerprints panel.

### Rollbar: Framework frames, and five "new" items

Rollbar split along the same seam. In 1.2.0 the payment error became items #13 and #14, one with framework frames and one without, and the coupon crash spread over three items. The version page counted the damage:

![Rollbar 1.2.0 version page with five new items](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/bd217271-0d4e-45d8-5656-057cd9645b00/md2x =1126x736)

**New (5)** held one bug that was new and four that weren't. Rollbar offers **Custom fingerprinting** per project and **Merge** on items. Separately, it titled every out-of-stock occurrence after the first book that ran out.

### Grouping comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Groups by message text | ✘: no | ✘: no |
| Framework or vendor frames in the fingerprint | ✔: even when hidden | ✔: yes |
| New payment bug in 1.2.0 | Two issues | Two items |
| Old coupon bug in 1.2.0 | Two new siblings | Two new items |
| Fixing it | Grouping rules, merge | Custom fingerprinting, merge |

**Verdict: Neither.** Both made one bug look like several after a release changed timing, which is the moment you most need an accurate count. Plan on writing a grouping rule in either tool for any Node.js backend.

[summary]
<iframe width="100%" class="aspect-video h-auto" src="https://www.youtube.com/embed/-26mmryojE4" title="Error tracking | Better Stack" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

PostHog and Rollbar both split the 1.2.0 payment bug on frames from Node and Express. In Better Stack, the same release produced one group:

![Better Stack single group for the payment error](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/e5e5a3b3-9db0-4323-aa84-fa0088103900/lg2x =1512x744)

Ten payment exceptions sit in that row, with the throwing code shown. The extra async frames from the slow query didn't produce siblings, so the new-error count stayed at one.

**[Group errors by your code](https://betterstack.com/error-tracking)**
[/summary]

## Releases and regressions

The 1.1.0 test was simple: mark the coupon bug fixed, leave the code alone, and ship.

### PostHog: Automatic reopen, manual context

Resolving in PostHog takes one click and asks for no version. The first 1.1.0 events flipped the issue straight back to Active:

![PostHog reopened issue back to Active](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/9ff03505-7522-4eea-c943-b828e2275c00/orig =1512x747)

No label marks it as reopened, in the list or on the page. The **Breakdown** panel splits its events by `app_version`, which answered "did it come back in 1.1.0" once I looked. Resolving also offered to email the two signed-in users who'd hit the bug, a feature I haven't seen elsewhere. Releases themselves were awkward: they come from source map uploads, named after git commits unless you pass the flags at inject.

### Rollbar: Fixed as of a version

In Rollbar, you can attach a version and a note when you resolve. When I resolved the coupon crash in 1.1.0 while the app still ran 1.0.0, it stayed resolved through 11 more events, since those came from the older version. Once 1.1.0 really ran, the item reactivated:

![Rollbar item reactivated with a suspected deploy](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/94db0dfe-26da-4c2b-0c21-4f65979d6c00/public =1126x736)

"Reactivated version: 1.1.0" and "Suspected deploy" link back to the deploy I'd reported. The version page put the bug under **Reactivated (1)**, apart from everything still active.

#### Auto-resolve on deploy

Before deploying 1.2.0, I switched on the setting that resolves everything at each deploy, for the API's environment only:

![Rollbar auto-resolve on deploy setting](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/87de8e6d-d44f-4d07-c1b8-b98948f61100/lg1x =676x442)

The 1.2.0 deploy resolved all six backend items, fixed or not. Three came back during traffic and showed as reactivated on the 1.2.0 page. The payment error was tied to that deploy as its suspect too:

![Rollbar payment error with its suspected deploy](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/d06e1bf1-c2c8-47ed-1fd5-9c087f308c00/orig =1126x736)

First version 1.2.0 and the deploy ID are on the item, so the question "what shipped this" has an answer on the page.

### Release comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Fix recorded against a version | ✘: not offered | ✔: plus a note |
| Returning bug reopened | ✔: any new event | ✔: from a later version |
| Names the deploy | ✘: not offered | ✔: Suspected deploy |
| Version pages | Release list from source maps | ✔: New, Reactivated, Still active, Resolved |
| Reopened label in the list | ✘: none | ✘: none |
| Events by version | ✔: Breakdown panel | ✔: first and latest version |
| Auto-resolve on deploy | ✘: not offered | ✔: per environment |
| Email affected users | ✔: offered | ✘: not offered |

**Verdict: Rollbar.** Version-aware resolving, a suspected deploy and a page per version are a complete release review. PostHog reopened the bug reliably, but answering which release brought it back took a breakdown and some setup. Rollbar fits teams that ship on a schedule, and PostHog fits teams that think in users more than versions.

[summary]
<iframe width="100%" class="aspect-video h-auto" src="https://www.youtube.com/embed/E8JQPRVR20E" title="On-call overview | Better Stack" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

Both tools reopened the coupon bug, and in both lists the row simply read as active again. Better Stack marked it in the list when 1.1.0 shipped:

![Better Stack errors list with a Reoccurred label](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/ff9ed40b-81f9-4dea-bca1-9d2fdeccd200/lg1x =1512x744)

Only the returning bug carries the red "Reoccurred" tag. You catch it while scanning the list, before you'd think to open a version page.

**[Flag regressions where you triage](https://betterstack.com/error-tracking)**
[/summary]

## Performance monitoring

1.2.0 slowed checkout's book query to seconds. One of these tools could see that.

### PostHog: Percentiles by version

PostHog's tracing comes from the OpenTelemetry SDK. **Tracing → Operations** with the version facet set to 1.2.0 showed the problem:

![PostHog operations table for 1.2.0](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/f680cf41-25a5-4403-e985-6b946f982200/md2x =1512x747)

`POST /checkout` reached 4.76 s at p95 and `SELECT book for checkout` 2.93 s. With the filter on 1.1.0, checkout's p95 was 4.21 ms. A slow `GET /search` also stood out, but its gap sat in uninstrumented code and was there on every version.

### Rollbar: Nothing to measure

Rollbar has no tracing, RUM or performance product. Checkouts in 1.2.0 ran three to five seconds each, and nothing in Rollbar changed to show it. Replay events show request durations, but only around errors and one visit at a time.

### Performance comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Server spans | ✔: OpenTelemetry | ✘: not offered |
| Percentiles by release | ✔: version facet | ✘: not offered |
| Request timing in replays | ✔: network tab | ✔: around errors only |
| Browser performance | Web Vitals autocapture, not reviewed | ✘: not offered |

**Verdict: PostHog.** It found the slow query in two clicks. With Rollbar you need a separate tracing tool for this.

## Logs and querying

PostHog stores logs. Rollbar stores errors and lets you query them.

### PostHog: Logs with patterns and live tail

Over OpenTelemetry, the app's log lines flowed into PostHog's logs product, about a thousand in the first hour, filterable by level, service and host:

![PostHog logs viewer with facets](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/e6ebea39-de0b-445a-cfe7-daced1d90100/lg1x =1512x803)

Patterns, grouping and live tail sit beside the viewer, and the same lines show up on each trace. PostHog's SQL works across events too, and I used it to check raw exception data.

### Rollbar: RQL over occurrences

Rollbar's telemetry includes console lines, so my slow-query warnings appeared inside item timelines with no search. **RQL** is an SQL-like language over occurrences, on the Advanced plan. This query, which I ran during the test, counts occurrences per item:

```text
SELECT item.counter, item.title, count(*)
FROM item_occurrence
GROUP BY item.counter, item.title
```

It follows SQL's GROUP BY rules strictly, and each new query starts with no project selected.

### Logs and querying comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Searchable log storage | ✔: free up to 10 GB monthly | ✘: not offered |
| Logs for one request | ✔: on the trace | ✘: process-wide telemetry |
| Query language | ✔: SQL over events | ✔: RQL over occurrences |
| CSV export and metrics API | Not tested | ✔: RQL |

**Verdict: PostHog.** It stores and searches logs and joins them to requests. RQL is a strong tool for slicing errors, though logs still need a home elsewhere.

[summary]
<iframe width="100%" class="aspect-video h-auto" src="https://www.youtube.com/embed/XJv7ON314k4" title="Live tail overview | Better Stack" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

PostHog joined logs to traces, and Rollbar kept console lines as unsearchable telemetry. Better Stack's live tail filtered to the failing 1.2.0 checkout in my test:

![Better Stack live tail filtered to one checkout](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/0bd2859e-1627-424b-5fcb-b7bb7027c200/public =1512x744)

Filtering on that request's trace keeps its slow-query warning and drops everyone else's traffic. The same lines stay searchable long after the incident.

**[Search logs alongside your errors](https://betterstack.com/log-management)**
[/summary]

## Alerts

No alert reached me from either tool, so this compares setup only.

### PostHog: Rules ready, destination missing

The issues list carries a banner until you connect Slack, Teams, PagerDuty or another destination:

![PostHog banner asking for an alert destination](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/a370c83c-79b0-4368-0714-566d17c10100/md1x =1512x747)

New, reopened and spiking issues are the triggers, and configuration adds spike detection, rate limits, assignment and severity rules.

### Rollbar: Email rules from day one

A new Rollbar project comes with 11 email rules already active. They cover new and reactivated items, deploys and new versions, plus a daily digest and a rule for sudden bursts. Slack, Jira, GitHub, PagerDuty, Opsgenie, Datadog and webhooks are the other channels.

### Alerts comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Works with no setup | ✘: needs a destination | ✔: email rules on |
| Reopened errors | ✔: trigger | ✔: Item reactivated |
| Deploy and version events | ✘: not offered | ✔: rules on by default |
| Spike detection | ✔: in configuration | ✔: burst rule |

**Verdict: Not compared.** Nothing was delivered. On paper, Rollbar alerts the moment you install it, and PostHog waits for a destination.

## AI-assisted debugging

PostHog AI lives inside the product and can also hand prompts to outside tools. Rollbar's **Root cause & fix** connects to your GitHub repositories, and I didn't connect one, so only PostHog was tested.

### PostHog: Right on the mechanism, wrong on the details

**Open Fix prompt** on an issue can send an explain or fix prompt to PostHog AI or to an editor assistant:

![PostHog Fix prompt menu](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/bca03679-5498-4c49-4a8e-ac8ab14bb700/orig =1512x747)

On the coupon crash, PostHog AI explained the null access correctly and then invented coupon codes my app doesn't use. On the 1.2.0 payment issues, it blamed the split on amounts in the message, reconstructed code it couldn't see, and never linked the failures to the release or the slow query.

### Rollbar: Code-aware, once connected

**Root cause & fix** lists related occurrences, then asks for a GitHub connection to read your code. Each run uses AI credits: the trial came with some, and paid tiers begin at 4,000 monthly. Rollbar also has an assistant in the RQL editor. I tried neither.

### AI comparison

| Capability | PostHog | Rollbar |
|---|---|---|
| Assistant in the product | ✔: PostHog AI | ✔: Root cause & fix, untested |
| Reads your code | ✘: stack frames only | ✔: through GitHub |
| Prompts for outside tools | ✔: Claude Code, Cursor, Codex | ✘: not found |
| Free usage | 500 credits a month | ✘: no credits on Free |

**Verdict: Not compared.** PostHog AI was quick and too willing to guess without the code. Rollbar's design addresses that gap, and I can't say how well it works.

[summary]
<iframe width="100%" class="aspect-video h-auto" src="https://www.youtube.com/embed/3bw21kiNAuM" title="AI SRE and MCP | Better Stack" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

PostHog AI filled gaps with guesses, and Rollbar's analysis waits on a GitHub connection. Better Stack's AI SRE answered the 1.2.0 question in my test from telemetry alone:

![Better Stack AI SRE explaining release 1.2.0](https://imagedelivery.net/xZXo0QFi-1_4Zimer-T0XQ/9c18a3bf-a83b-4e4c-2b40-adaf417dfc00/md2x =1512x744)

It pinned the slowdown on checkout's query and found 10 rejected charges among 48, all from 1.2.0. The investigation ran about four minutes for $0.49, and it's reachable over MCP from your editor as well.

**[Let AI SRE explain a bad release](https://betterstack.com/ai-sre)**
[/summary]

## Pricing

PostHog meters each product separately above a shared monthly free tier. Rollbar meters error occurrences and replays, with AI credits on paid plans.

I checked both pages on November 12, 2026. Rollbar's paid plans showed a dash in place of a price, so its figures are from my October 23 reading, and PostHog's per-unit exception rate is from October 28. Confirm both before buying.

### Free plans and trials

| Plan detail | PostHog Free | Rollbar Free |
|---|---|---|
| Errors | 100,000 exceptions monthly | 5,000 occurrences monthly |
| Replays | 5,000 recordings monthly | 1,000 replays monthly |
| Logs | 10 GB monthly | ✘: not offered |
| Error retention | 1 year of events | 30 days |
| AI | 500 PostHog AI credits | ✘: none |
| Users | Unlimited | Unlimited |
| Projects | 1 | Not listed |

Rollbar's trial runs the Advanced plan for 14 days. PostHog has no trial, since the free plan is the starting point.

### Entry-level paid plans

| Paid plan | PostHog Pay-as-you-go | Rollbar Essentials | Rollbar Advanced |
|---|---|---|---|
| Base price | $0 | From $9 a month | From $13 a month |
| Included errors | 100,000 free, then $0.000370 each | From 10,000 occurrences | From 10,000 occurrences |
| Retention | 2 years of events | 90 days | 180 days |
| AI credits | 500 free, then usage based | From 4,000 a month | From 8,000 a month |
| Query language | SQL | ✘: not included | ✔: RQL |
| Projects | 6 | Not listed | Not listed |

### What costs extra

| Need | PostHog | Rollbar |
|---|---|---|
| More errors | Per exception past the free tier | A bigger tier, or on-demand at the plan rate |
| Tracing | Usage based | ✘: needs another tool |
| Logs | Past 10 GB, plus paid retention | ✘: needs another tool |
| Full session recording | Past 5,000 a month | ✘: clips only |

### Comparing the actual cost

A small app with a few thousand errors fits both free plans, but PostHog's covers 20 times the errors, five times the recordings, plus logs and tracing. Rollbar's paid tiers start cheap, under $15 a month, and stop at your limit by default, so a noisy release can't run up a bill.

PostHog's spend grows across several meters at once, so set caps per product before your first bad deploy. For a page-view model to compare against, see our [PostHog vs TrackJS comparison](https://betterstack.com/community/comparisons/posthog-vs-trackjs/), and for Rollbar's against the same, our [TrackJS vs Rollbar comparison](https://betterstack.com/community/comparisons/trackjs-vs-rollbar/).

**Verdict: PostHog.** Its free tier covers far more ground. Rollbar is the cheaper paid error tracker if errors are all you buy.

## Full feature comparison

| Feature | PostHog | Rollbar |
|---|---|---|
| Browser and server in one project | ✔: one list | ✔: one list |
| Unhandled rejection with an app listener | ✘: missed | ✔: captured |
| Severity on rows | ✔: editable | Level only |
| Source maps by script | ✔: CLI | ✔: API per version |
| Function names from maps | ✘: anonymous | ✔: recovered |
| Server source lines | ✔: from disk | ✘: not shown |
| Trace from an error | ✔: View trace | ✘: not offered |
| Value frequency | ✘: not offered | ✔: Typicality |
| Re-send a request | ✘: not offered | ✔: curl |
| Session replay | ✔: full sessions | ✔: clips around errors |
| Grouping overrides | ✔: Grouping rules | ✔: Custom fingerprinting |
| Resolve in a version | ✘: not offered | ✔: with a comment |
| Suspected deploy | ✘: not offered | ✔: on the item |
| Version pages | Release list only | ✔: one per version |
| Resolve everything at deploy | ✘: not offered | ✔: per environment |
| Email affected users | ✔: on resolve | ✘: not offered |
| Tracing | ✔: OpenTelemetry | ✘: not offered |
| Logs | ✔: with live tail | ✘: telemetry only |
| Query language | ✔: SQL | ✔: RQL |
| Default alerts | ✘: needs a destination | ✔: 11 email rules |
| AI | ✔: PostHog AI | Root cause & fix with GitHub |
| Free errors | 100,000 a month | 5,000 a month |

## Which should you choose?

The overlap is error tracking and replay. Past that, PostHog adds observability and Rollbar adds release discipline.

### Choose PostHog if errors are one signal among many

- **You want the trace and logs next to the error.** One click took me from the coupon crash to its spans and the three log lines from that request.
- **Performance regressions matter.** Percentiles by version found the 1.2.0 query without another tool.
- **You'd like it free for now.** The free tier spans errors, recordings, logs and tracing.

The trade-offs: grouping that counts hidden frames, releases tied to git unless configured, alerts that need a destination, and an AI that guesses. For PostHog next to an error tracker with deeper release features, see our [Sentry vs PostHog comparison](https://betterstack.com/community/comparisons/sentry-vs-posthog/).

### Choose Rollbar if each release gets reviewed

- **You resolve against versions.** Resolve in 1.1.0, see it reactivate with a suspected deploy, and read the version page.
- **You reproduce API bugs by hand.** Typicality and the curl command shorten that loop.
- **You want alerts without setup.** Eleven email rules are live on day one.

The trade-offs: no tracing or logs, short replays, process-wide server telemetry, and grouping that needs fingerprint rules. Our [Sentry vs Rollbar comparison](https://betterstack.com/community/comparisons/sentry-vs-rollbar/) puts it against a tool that adds tracing.

## FAQ

### Can PostHog resolve an error in a specific version?

No. PostHog's Resolve has no version option, and any new event reopens the issue. Its Breakdown panel shows which version the new events came from.

### Does Rollbar have performance monitoring?

No. Rollbar has no tracing, RUM or APM. Replays show request durations around errors, and that's the only timing it keeps.

### Why did both tools create new errors for old bugs in 1.2.0?

Both include framework frames under your code in their fingerprints. The slow query in 1.2.0 changed which Express and Node frames appeared, so the same crash got new fingerprints. Grouping rules in PostHog or custom fingerprinting in Rollbar fix it.

### Which has the better free plan?

PostHog's, by a wide margin. It allows twenty times as many errors and five times as many recordings, and adds logs, against Rollbar's 5,000 occurrences and 1,000 replays.

## Final thoughts

PostHog and Rollbar both caught every bug that mattered and both stumbled on the same grouping trap. Where they part ways is what surrounds the error. PostHog puts the trace, the logs and the recording around it. Rollbar puts the version, the deploy and the release review around it.

So the decision is which question you ask first after a bad deploy. If it's "why is this slow and what did this user hit", PostHog answers it without another tool. If it's "which deploy did this and what else came back", Rollbar answers it without any setup beyond reporting deploys.

Whichever you pick, **write a grouping rule before your next release changes the timing**.