📡 HAR Viewer
View HTTP Archive (HAR) files: waterfall chart, request details, headers, timings, and filters.
Drop a .har file here, or click to browse
About this tool
This tool visualizes HTTP Archive (HAR) files — the standard format exported by browser DevTools for recording network activity. Drop a .har file from Chrome, Firefox, or any other browser, and you'll see a waterfall chart of every request with its method, URL, status code, size, and duration.
It's useful for debugging page load performance, auditing third-party requests, checking response headers, and analyzing API call timing. Click any row to expand full request and response headers, timing breakdowns, query parameters, cookies, and raw JSON.
Example: export a HAR from a slow-loading page, open it here, and sort by time to find the bottleneck. Or filter by status 4xx to find broken resources, or by type XHR/Fetch to inspect API calls.
FAQ
How do I export a HAR file from my browser? ›
In Chrome/Edge: open DevTools (F12), go to the Network tab, check "Preserve log", load/reload the page, then right-click any request and choose "Save all as HAR with content". In Firefox: Network tab → right-click → "Save All As HAR".
Does this tool send my HAR data anywhere? ›
No. The HAR file is parsed and rendered entirely in your browser. No data is uploaded to any server — the tool works offline after the page loads.
What are the colored segments in the waterfall bar? ›
Each color represents a phase of the request: grey for blocked/stalled, blue for DNS lookup, orange for TCP connect, purple for SSL handshake, light green for sending the request, yellow for waiting (TTFB), and teal for receiving the response.
Why do some entries show 0 B size? ›
Browser DevTools sometimes report content size as 0 for cached responses, redirects, or requests blocked by extensions. The tool shows what the HAR reports — check the response headers for Content-Length or Transfer-Encoding to verify.