Free HAR File Analyzer
Drop a .har file exported from your browser DevTools and get instant traffic analysis. The tool surfaces the slowest 10 requests, largest 10 transfers, full host-by-host breakdown with tracker detection, redirect chains, and a waterfall of all requests filterable by URL or status. HAR files often carry auth cookies, so everything is parsed locally in the browser.
How to use
- 01Open the page you want to analyze in Chrome, Firefox, or Edge. Press F12 to open DevTools.
- 02Switch to the "Network" tab. Make sure recording is on (red dot in Chrome / circle in Firefox).
- 03Refresh the page to capture all requests. Wait until the page fully loads.
- 04Right-click any row in the Network panel, choose "Save all as HAR with content" (Chrome) or "Save all" (Firefox).
- 05Drop the resulting .har file into this tool. Stats appear immediately.
- 06Use the waterfall filter to drill into a specific domain or status code.
FAQ
What is a HAR file?▼
HTTP Archive Format. A JSON document that records every HTTP request and response a browser made on a page, plus timing breakdowns (DNS, connect, TLS, send, wait, receive). It is the standard way to share network captures with developers.
Are HAR files safe to share?▼
They include request and response headers, which usually means cookies and Authorization tokens. Anyone with the HAR can replay your authenticated requests until those tokens expire. Strip cookies before sharing externally, or share only with trusted parties.
How does the tool detect trackers?▼
It matches request hostnames against a small built-in list of well-known analytics, advertising, and tag-management providers (Google Analytics, GTM, Facebook, Hotjar, Segment, Amplitude, etc). It is not a comprehensive blocklist and may miss niche trackers, but it catches the obvious ones.
What does the waterfall show?▼
Each row is one request, positioned horizontally according to its actual start time and duration relative to the page load window. The width of the colored bar is the time the browser spent on that request. Stacked or rightward-shifted bars indicate sequential dependencies; gaps may indicate browser-side throttling or main-thread blocking.
Why is the slowest request often a small POST?▼
Network time is dominated by the wait phase (server processing). A 200-byte POST that triggers a database query can take longer than a 5 MB image download served from a CDN. The slowest list highlights wait time, not transfer size.