Free online HAR file viewer
HAR Analyzer
Open a HAR file to find blocked requests, proxy errors, redirects, slow timing, and Cloudflare error hints. The file is parsed in your browser and never uploaded.
Drop a Chrome, Edge, Safari, or Firefox .har export. Processing stays in this browser.
HTTP status code distribution and error rate
Blocked, failed, and rate-limited request candidates
Redirect chains, slowest requests, and HAR timing phases
Request and response header patterns
Cookie flags, cookie domains, and Cloudflare Ray ID hints
HAR files can contain cookies, tokens, and request URLs. This tool is designed for local review before you share a redacted report.
HAR file debugger
Find request failures before you blame the wrong layer
A HAR file records the browser's network timeline. This analyzer turns that raw HTTP archive into a readable report for access denied pages, slow requests, redirect loops, proxy authentication failures, cookie problems, and Cloudflare-branded responses. The code runs on this page only. Your HAR does not leave your device.
HAR data is parsed in the browser while you use the page.
Large captures are read on your device, not on a server.
Status groups, redirects, errors, and no-response entries.
Highlights common challenge, access, rate-limit, and 52x hints.
Capture a HAR
How to export a HAR file
Open the developer tools before you load the page, turn on log preservation, and reproduce the problem. Then export the log.
Chrome and Edge
- Press F12 and open the Network panel.
- Check Preserve log.
- Reload the page and reproduce the problem.
- Click Export HAR (sanitized) in the Network toolbar and save the .har file.
Firefox
- Press F12 and open the Network tab.
- Turn on Persist Logs in the Network toolbar or its gear menu.
- Reload the page and reproduce the problem.
- Right-click any request and choose Save All As HAR.
Safari
- In Safari Settings > Advanced, turn on Show features for web developers (Show Develop menu in older versions).
- Open Develop > Show Web Inspector and select the Network tab.
- Check Preserve Log, then reload and reproduce the problem.
- Click Export (or press Command-S) to save the .har file.
Privacy
Sanitize a HAR before you share it
A full HAR can hold session cookies, Authorization headers, tokens in URLs, and form data. Anyone with those values may be able to use your session. This analyzer does not upload the file, but the person you send it to will see everything in it.
Timing breakdown
Read HAR timing like an operator
Status codes tell you what happened. Timing tells you where it happened. Use both before changing proxies, retry logic, request headers, or monitor delays.
Blocked / queued
Time spent waiting before the browser could start the request. High values often point to browser concurrency, service worker, or proxy pool pressure.
DNS, connect, SSL
Connection setup time. Spikes here can expose DNS issues, proxy latency, TLS handshakes, or regional routing problems.
Waiting (TTFB)
Time until the first response byte. This is where origin slowness, Cloudflare checks, and application-side blocks often show up.
Proxy and blocking diagnostics
What blocked requests in a HAR mean
The analyzer shows these signals in its blocked requests list, status codes, and Cloudflare hints. Use the table to find the layer to fix before you change proxies, headers, or retry logic.
A 407 comes from the proxy, not the website. Check the credentials and the proxy string format with our 407 Proxy Authentication Required guide, and fix the format with the proxy formatter.
A 403 or a Cloudflare 1020 page comes from the site. See HTTP 403 Forbidden causes and fixes and Cloudflare Error 1020. For 429 responses, lower the request rate first. Our HTTP 429 guide covers backoff, and the proxy delay calculator sizes a monitor pool for a given delay.
HAR analyzer FAQ
Answers before you inspect a network log
Is my HAR file uploaded to Unknown Proxies?
+
No. The HAR analyzer parses the file in your browser. The upload control reads the file on your device, and the page does not send your HAR contents to a server.
How do I open a HAR file?
+
Drop the .har file on the analyzer, choose it with the file picker, or paste the HAR JSON and click Analyze HAR. A HAR is a JSON file, so a text editor can open it too, but the analyzer groups the requests by status, timing, and host.
What can a HAR analyzer diagnose?
+
It summarizes status codes, redirects, failed and blocked requests, request timing, headers, cookies, cache behavior, and Cloudflare hints such as Ray IDs or common error codes.
Can this find proxy errors like 407?
+
Yes. The analyzer flags 407 Proxy Authentication Required responses and requests with no response as blocked or failed. A 407 means the proxy rejected the login, so check the credentials and proxy format first.
Can this find Cloudflare Error 1020 or 1015?
+
Yes. If the HAR includes Cloudflare response headers, challenge pages, or page text that mentions errors like 1020 or 1015, the analyzer shows those hints.
What should I remove before sharing a HAR?
+
Remove cookies, Authorization headers, tokens in query strings, and form data such as passwords. Chrome and Edge export a sanitized HAR by default that leaves out Cookie, Set-Cookie, and Authorization headers. Check Firefox and Safari exports by hand.
Need better proxy behavior after debugging?
Compare ISP and residential proxy plans for scraping, monitoring, account workflows, and other sensitive automation use cases.