Upload a HAR file or paste JSON content to visualize HTTP request waterfalls, response headers, and performance metrics. Pure client-side processing, no data upload.
Drag & drop HAR file here, or click to select
Supports .har files up to 50MB
HAR File Viewer - Web Performance Analysis Tool
The HAR File Viewer is an online tool designed for web developers and DevOps engineers. By parsing HTTP Archive (HAR) files, you can visually inspect all HTTP interactions between the browser and server, including request waterfalls, response time analysis, resource loading statistics, and other key performance metrics.
Why choose HAR File Viewer
- Request Waterfall - Visualize DNS, TCP, SSL, TTFB, and download phases for each request
- Smart Filtering - Filter requests by URL, resource type, or status code
- Domain Statistics - Aggregate request count, transfer size, and timing by domain
- Request Details - View full request/response headers and timing breakdown
- Performance Overview - Total requests, transfer size, page load time at a glance
When to use HAR File Viewer
- Performance Optimization - Identify slow requests and resource loading bottlenecks
- Troubleshooting - Check status codes and response headers to diagnose network issues
- Security Audit - Inspect requests for sensitive information leakage
- API Debugging - View complete XHR/Fetch request/response cycles
FAQ
What is a HAR file?
HAR (HTTP Archive) is a JSON format file that records HTTP interactions between a browser and server. It contains request URLs, methods, headers, response status codes, response headers, body sizes, timestamps, and more β essential for web performance analysis and troubleshooting.
How do I export a HAR file?
In Chrome: 1) Open DevTools (F12); 2) Go to the Network tab; 3) Perform the actions you want to record; 4) Right-click the request list and select "Save all as HAR with content". Firefox and Edge support similar operations.
Does a HAR file contain sensitive information?
Yes, HAR files may contain cookies, Authorization headers, POST request bodies, and other sensitive data. This tool processes everything locally in your browser β no data is uploaded to any server. Always review and remove sensitive info before sharing HAR files.
What size HAR files are supported?
This tool supports HAR files up to 50MB. For files with many requests, use the filter feature to narrow by domain or type for a better browsing experience.
What do the waterfall chart timing phases mean?
The waterfall chart shows each request's phase timings: DNS lookup (purple), TCP connect (orange), SSL handshake (green), request sending (dark blue), waiting for response (light blue), content download (gray). Analyzing these phases helps identify performance bottlenecks.