Error log grouper
Paste error logs or a JSON error export and group repeated errors by their stack trace fingerprint. Each group shows its count, first and last time seen and one full example.
Up to 2,000,000 characters of logs or exports and 1,000,000 errors. Processing runs locally in a background worker in your browser. Downloads: a JSON report and a CSV of groups. Paste server or browser logs with stack traces, or an export from your error tracker. Up to 2,000,000 characters. Review the settings before running.
Your result
How to use Error log grouper
- Paste error logs or a JSON, NDJSON or CSV error export.
- Choose how many stack frames make up a fingerprint.
- Run the grouping and review the largest groups first.
- Download the JSON report or the CSV of groups.
Useful next steps
Stack formats
Frames from V8 (Chrome and Node.js), Firefox and Safari, Java, Python and .NET are recognised. A text log is split into errors at each line that is not a stack frame. Python tracebacks are read with their final exception line.
How fingerprints work
A fingerprint combines the error type with the top stack frames. File paths lose their origin, query string and bundle hashes such as app.3f2a1b9c.js, so builds of the same code group together. Line numbers and the message are left out unless you include them. Errors with no frames use the normalised message, where numbers, quoted text and ids are replaced by placeholders.
Merging near matches
A similarity below 1 merges groups whose frames and message words have at least that Jaccard similarity. This can merge errors that are only related, so start at 1 and lower it only when groups look split.