HAR File Analyzer

Drop a .har file to inspect every network request — status, size, timing, headers, and response body. 100% client-side.

About HAR File Analyzer

The HAR File Analyzer is a privacy-first inspector for HTTP Archive (.har) files exported from any modern browser's DevTools. It parses the HAR JSON, summarizes total requests, transferred size, and load time, and lets you drill into every request to see headers, body, timing breakdown, and status — without uploading the file anywhere.

HAR files are the standard format developers, QA teams, and support engineers use to share network diagnostics. They contain everything needed to reproduce a network issue: request headers, response bodies, timings, and server addresses. Because that data is sensitive, this tool runs entirely in your browser.

How to Use HAR File Analyzer

  1. Open your browser's DevTools (Chrome/Edge: F12, Firefox: F12, Safari: Cmd+Option+I) and switch to the Network tab.
  2. Reload the page or perform the actions you want to capture so the requests appear in the Network panel.
  3. Right-click any request and choose Save all as HAR with content (Chrome/Edge) or Save All As HAR (Firefox/Safari).
  4. Drop the resulting .har file into the upload zone above, or paste its JSON contents into the text area.
  5. Use the summary cards to spot 4xx/5xx errors and slow requests, then click any row to expand its full headers, body, and timing breakdown.
  6. Filter by method, status bucket, or content type — or use the search box to find a specific URL or MIME type.
  7. Use the Copy buttons to grab individual header values or the full response body for further debugging.

Common Use Cases

  • Debug failing API calls reported by support engineers or end users.
  • Find slow third-party requests dragging down page load time.
  • Audit the headers and cookies a page sends to detect leaks of sensitive data.
  • Reproduce a flaky network issue by inspecting the exact request/response pair captured in production.
  • Verify CSP, CORS, and cache-control headers across many requests at once.
  • Review what gets loaded on a competitor's page or your own page during QA.
  • Share findings with teammates by pointing at specific status, size, or timing anomalies.

Frequently Asked Questions