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HomeDeveloper UtilitiesHAR File Viewer

Example: HAR File Viewer

A worked example, rendered from real sample data. Sign in to run the tool on your own input.

Input
{"log":{"version":"1.2","creator":{"name":"Chrome"},"entries":[{"request":{"method":"GET","url":"https://api.example.com/users"},"response":{"status":200,"bodySize":1234},"time":150},{"request":{"method":"POST","url":"https://api.example.com/users"},"response":{"status":201,"bodySize":256},"time":89}]}}
Output
HAR 1.2 · Chrome

SUMMARY
  Requests          2
  Transferred       1.5 KB
  Uncompressed      1.5 KB
  Wall clock        239 ms
  Sum of durations  239 ms
  Server wait       239 ms
  Queued/blocked    0 ms
  Domains           1

STATUS   2xx: 2
TYPE     other: 2

BY DOMAIN
  api.example.com                           2 req      1.5 KB     239 ms

SLOWEST 2 REQUESTS
     150 ms  GET    200  https://api.example.com/users
      89 ms  POST   201  https://api.example.com/users

FINDINGS (0)
  Nothing notable — no failures, redirects or obvious caching gaps.

REQUESTS
     # Method  Status  Type              Size      Time  URL
  --------------------------------------------------------------------------------------------------------
     1 GET     200     other           1.2 KB    150 ms  https://api.example.com/users
     2 POST    201     other            256 B     89 ms  https://api.example.com/users

About HAR File Viewer

HAR File Viewer preview - Developer Utilities tool

Explore a HAR network log: waterfall, timings, sizes and findings. Part of the DevTools Surf developer suite. Browse more tools in the Developer Utilities collection.

Use Cases

  • Frontend developers diagnosing slow page load times
  • QA engineers documenting network failures in bug reports
  • Security auditors reviewing API calls for data leaks
  • Performance engineers analyzing third-party script impact

Tips

  • Sort entries by response time to find slow requests
  • Filter by MIME type to isolate API calls from assets
  • Check the waterfall timing to spot blocking requests

Fun Facts

  • The HAR (HTTP Archive) format was standardized by the W3C Web Performance Working Group in 2012, based on work by Jan Odvarko of Mozilla.
  • A single page load on a modern website can generate a HAR file with over 200 entries, sometimes exceeding 10 MB in size.
  • HAR files can accidentally contain sensitive data like cookies and auth tokens — the spec includes a 'comment' field to flag redacted entries.

FAQ

What's a HAR file?
HTTP Archive — a JSON dump of network activity from browser DevTools. Captures every request, response, timing, headers, and body.
What does the viewer show?
Waterfall chart of requests, per-request details (timing, size, headers, body), and summary stats (total time, transferred bytes, blocking requests).
Can I see the response body?
Yes — full request and response bodies are in the HAR. The viewer displays them with content-type-aware rendering (JSON, HTML, images).

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