Tool Fu
$ toolfu run har-viewer

HAR File Viewer & Analyzer — Free Online

Free online HAR file viewer and analyzer. Analyze HAR files with request summaries, status codes, sizes, and timing — no upload, your data stays on your device.

all processing runs in your browser
har-viewer
input > drop .har file

$ drop a HAR file here or click to browse

.har or .json files

or paste from clipboard (⌘V / Ctrl+V)

Analyze HAR Files Online — Free HAR File Analyzer

This free online HAR file viewer and HAR analyzer lets you view and analyze HTTP Archive files without uploading sensitive data to any server. Drop a .har file or paste HAR JSON to see a summary of all network requests with color-coded status codes, timing data, and response sizes.

What the HAR file analyzer shows

  • Total number of requests, data transferred, and page load time
  • Individual request details: HTTP method, URL, status code, size, and duration
  • Color-coded status codes for quick identification of errors and redirects

Why use an online HAR analyzer?

HAR file analysis helps debug slow page loads, identify failed requests, find large resources, and understand network call sequences. HAR files can contain sensitive data like cookies and auth tokens — this HAR viewer processes everything locally in your browser, keeping your data private.

$ cat FAQ.md
What is a HAR file?▶
A HAR (HTTP Archive) file is a JSON-formatted log of a browser's interaction with a website. It contains detailed information about each HTTP request and response, including URLs, methods, status codes, headers, body sizes, and timing data. You can export HAR files from browser DevTools.
How do I export a HAR file from my browser?▶
In Chrome/Edge: Open DevTools (F12) → Network tab → Right-click → Save all as HAR with content. In Firefox: DevTools → Network → gear icon → Save All As HAR.
Is my HAR file uploaded anywhere?▶
No. The HAR file is parsed entirely in your browser using JavaScript. Nothing is sent to a server. HAR files can contain sensitive data like cookies and auth tokens, so this local processing is important for security.
What do the status code colors mean?▶
Green (2xx) means success, yellow (3xx) means redirect, and red (4xx/5xx) means client or server error.