HAR Analyzer: Inspect HTTP Archive Files Online
A HAR analyzer opens the HTTP Archive files your browser exports from the Network tab and makes them explorable: every request with method, status, size, and duration, filters for failures and slow calls, and per-request drill-downs into headers and the timing waterfall (DNS, connect, TLS, wait, receive). Because HAR files routinely contain cookies and auth tokens, this analyzer runs entirely in your browser and the file is never uploaded.
How it works
- 1
Export a HAR from your browser (DevTools → Network → Export HAR) and upload or paste it.
- 2
Click Analyze HAR: totals, domains, and every request appear instantly.
- 3
Filter by status class, speed, or URL, and expand any request for headers and timing breakdown.
Frequently asked questions
How do I open a HAR file?
A HAR file is just JSON, but reading it raw is painful. Upload it above (or paste the contents) and it renders as a filterable request table with expandable details: the same information as the DevTools Network tab, shareable and reviewable after the fact.
How do I create a HAR file?
In Chrome, Edge, or Firefox: open DevTools (F12) → Network tab, reproduce the problem, then click the export/download icon (Export HAR). Enable 'Preserve log' first if the issue spans page navigations.
Are HAR files safe to share?
Be careful: HAR files capture full request and response headers, including cookies, session tokens, and Authorization headers. Sanitize them before sharing with third parties. This analyzer never uploads the file (analysis is 100% in-browser), so inspecting one here doesn't expose it.
What do the timing phases mean?
blocked is time queued in the browser, dns is name resolution, connect/ssl are TCP and TLS setup, send is uploading the request, wait is time-to-first-byte from the server (usually the interesting one), and receive is downloading the response.
How do I find the slow request that's hurting my page?
Click the ≥1s filter to isolate slow requests, then expand them and look at the timing breakdown: a long wait means a slow backend, long connect/ssl suggests connection churn, and a long receive points at payload size.
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