Formatting logs

Live tail patterns

Live tail output of each source can be customized in Live tail by clicking on the gear icon in the upper right corner:

The Live tail pattern is a freeform text template with columns wrapped in {column} brackets.

LEVEL: {level}, PID: {context.system.pid}, THREAD: {context.runtime.thread_id}

Conditional rendering can be achieved by piping multiple values

LEVEL: {level}, THREAD or PID: {context.runtime.thread_id|context.system.pid}

If you have special characters in your fields such as dots, you can use square brackets instead:

LEVEL: {level}, THREAD: {context["thread.id"]}

Colors

You can format and color your logs using a subset of ANSI codes in your log messages.

For example, this is how you could format your logs using our JavaScript client:

logger.info("Logs can be \u001B[1mbold\u001B[0m, \u001B[31mred\u001B[0m, or \u001B[1;32mbold green\u001B[0m.");

Here's the result you would see in Live tail:

Supported colors

Live tail supports 31-36 and 91-96 code ranges for colors in both light and dark themes.

Supported font styles

• Bold: ANSI code 1
• Light: ANSI code 2
• Italic: ANSI code 3
• Underline: ANSI code 4

Style reset

Each font color or style needs to be reset by reset all modes (0) ANSI code. Better Stack Live tail doesn't support resetting a color or a style by starting a new one.