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.har

HAR test files

Valid HTTP Archive files with the entries, status codes, redirects and timings you choose, all on example.test hosts.

Open the .har generator

Or start from a preset

What is a HAR file?

Short answer

A HAR file is a JSON log of every network request a browser made: URLs, headers, status codes, bodies and timings. Browsers export it from DevTools, and support teams ask for it when something breaks. The format is HAR 1.2.

Every generated entry follows the HAR 1.2 rules: required fields present, sizes that match the bodies, a query string that matches the URL, and a total time equal to the sum of the timings. Secrets can be redacted the way sanitising tools do it.

Anatomy of a HAR file

  • log.version"1.2"
  • log.creatorThe tool that wrote the file
  • log.pages[]Each page load, with onContentLoad and onLoad
  • entries[].requestMethod, URL, headers, cookies, query string and post data
  • entries[].responseStatus, headers, content with MIME type and size
  • entries[].timingsblocked, dns, connect, ssl, send, wait, receive (ms)

What you can generate

  • 2xx, 3xx, 4xx, 5xx and failed requests (status 0)
  • Redirect chains with Location and redirectURL
  • Query strings, POST bodies and Unicode URLs
  • Cookies and Authorization headers, redacted or present
  • Base64-encoded image bodies and gzip sizes
  • Slow requests over 10 seconds
  • Broken on purpose: missing required fields or truncated JSON

How to make one

  1. Open the HAR generator, or start from a preset above.
  2. Set the size and switch on the edge cases you need; the preview and size estimate follow every change.
  3. Generate, then download. The file is made in your browser, and the same preset and seed always give you the same file.

Questions

No. Every URL, header and body is synthetic and points at example.test domains, so the files are safe to share in bug reports.

Chrome, Edge and Firefox DevTools can import HAR files, as can HAR viewers, Charles, Fiddler and many support tools.

Yes. Choose Missing required fields (no log.version, no timings on the first entry, no MIME type on the second) or Truncated JSON.

Yes. Each entry's time is the sum of its timings, ssl is part of connect, and DNS and connect are -1 when a connection is reused.

Related formats