HAR File Viewer

Inspect HTTP Archive (.har) logs, analyze network waterfall timings, and debug HTTP errors with 100% client-side privacy.

HTTP Archive (.HAR) Log Inspector

Analyze network waterfall timings, response codes, and request headers in-browser.

Total Requests

HTTP calls logged

Transferred Size

70.9 KB

Network payload

Success vs Errors

4 OK/1 Errors

2xx vs 4xx/5xx

Max Latency

310 ms

Slowest call

Status	Method	URL / Resource	Size	Time
200	GET	https://example.com/	18.0 KB	145 ms
200	GET	https://example.com/assets/app.min.js	44.1 KB	82 ms
200	GET	https://example.com/assets/styles.css	8.2 KB	64 ms
201	POST	https://api.example.com/v1/auth/session	412 B	210 ms
404	GET	https://api.example.com/v1/users/me/analytics	104 B	310 ms
304	GET	https://example.com/images/hero-banner.webp	0 B	125 ms

Diagnosing Real-World Web Performance Bottlenecks

When users report slow load times or broken checkout flows, screenshots rarely tell the whole story. The HTTP Archive standard provides an immutable, chronological snapshot of every network packet, DNS resolution, and TLS handshake. Visualizing this data in an intuitive waterfall view empowers engineers to diagnose latency regressions in minutes.

Use Cases

✓
Troubleshooting Production Web Latency
Isolate render-blocking JavaScript bundles, slow third-party analytics trackers, and heavy uncompressed image assets across the page lifecycle.
✓
API Integration & Authentication Debugging
Inspect HTTP status codes, OAuth bearer token authorization headers, query string parameters, and redirect chains without opening bloated dev environments.
✓
DevOps & Customer Support Ticket Analysis
Analyze `.har` files exported by end-users experiencing sporadic network timeouts, CORS errors, or CDN cache misses.
✓
Core Web Vitals & LCP Diagnostics
Identify high Time-To-First-Byte (TTFB) on root HTML documents and analyze the network critical path leading to Largest Contentful Paint.

Key Capabilities

✓

100% Client-Side In-Browser Execution

HAR files frequently hold sensitive session cookies and API tokens. All parsing runs strictly inside your local browser memory without transmitting logs to remote servers.

✓

Interactive Waterfall Timeline

Compare request latencies side-by-side with proportional duration bars to pinpoint slow bottlenecks instantly.

✓

Deep Header & Query String Inspection

Click any individual HTTP transaction to view complete request/response headers, cookies, and MIME payload parameters.

✓

Multi-Dimensional Filtering

Filter by URL pattern, HTTP verb (GET, POST, PUT), status group (2xx, 4xx, 5xx), or resource type (Fetch/XHR, JS, CSS, Media).

Frequently Asked Questions

What is a HAR (.har) file?

A HAR (HTTP Archive) file is a standardized JSON-formatted archive that records all network interactions between a web browser and servers. It captures request/response headers, cookies, URL endpoints, connection timings, and payload sizes.

How do I export a HAR file from Google Chrome or Edge?

Press F12 (or right-click -> Inspect) to open DevTools -> Click the 'Network' tab -> Reload the page to reproduce the issue -> Click the download icon (Export HAR...) with the downward arrow located above the request table.

Is it safe to upload HAR files here?

Yes, because Stilest does not upload your file anywhere. The file is read directly using JavaScript's local `FileReader` API on your device. Your data never touches our server.

Why do HAR files sometimes contain sensitive security information?

Because HAR files record full HTTP headers, they can include authorization tokens (e.g. `Authorization: Bearer ...`), session cookies, and form submission data. Always ensure you do not share untrusted HAR files publicly.