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Log File Viewer

Open large .log files instantly, filter by level, search with highlights or regex, and read JSON-lines logs as tidy rows. Streamed and private in your browser.

No uploads

How to use Log File Viewer

  1. 1Open Log File Viewer. It runs in your browser, no sign-up.
  2. 2Drop your file here or choose it. It stays on your device; nothing is uploaded.
  3. 3Adjust the options until the preview looks right.
  4. 4Download the result.

Questions

How large a log can it open?

The file is streamed and only the visible lines are drawn, so logs with millions of lines open fine. The practical limit is your device’s memory — roughly a couple of gigabytes.

Does it understand JSON logs?

Yes. JSON-lines logs (pino, bunyan, Winston, structlog, ECS…) are detected automatically: the level, time and message are pulled out, and you can click a line to see the full object.

Is my log uploaded?

No. The file is read in your browser and never leaves your device.

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