Category: Developer tools
HAR File Viewer
Inspect browser network logs locally, including timings, status codes and request details
Open a HAR file locally and inspect requests, status codes, domains, timings and sizes in your browser. Network logs are never uploaded, and requests are never replayed.
A HAR is a full recording of a browsing session and routinely contains cookies, Authorization headers and whole request bodies. This one is read in your browser and never uploaded — look at it here before you attach it to a ticket.
Export a HAR from your browser's Network panel, then open it here.
Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
A HAR file is what your browser's Network panel writes when you export a session: every request, its headers, its timings and often its body. That makes it the most useful thing to attach to a bug report and one of the most dangerous — session cookies, Authorization headers and tokens sitting in query strings all travel with it. This viewer turns the export into a filterable request table inside your own tab, summarises what was slow and what failed, and flags the entries carrying credentials so you can see what a recipient would see. It reads the JSON and nothing else: no request is ever sent again.
How to use it
- Export a HAR from your browser's Network panel, then choose the file here.
- Filter by URL, method, status class or domain, and sort by time or size to find the slow or failing requests.
- Select a URL for its details, and check the flagged rows before sharing the file with anyone.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- What is a HAR file?
- HTTP Archive: a JSON recording of the network activity of a browsing session, exported from a browser's developer tools. It lists each request and response with headers, timings and sizes.
- Are cookies or tokens uploaded?
- No. The file is read in your browser tab and never sent anywhere. That is precisely why this is worth doing locally — a HAR often contains live session cookies and authorisation headers, so uploading one to an online analyser hands them to a third party.
- Can I filter slow requests?
- Yes. Sort by time to bring the slowest to the top, and the summary shows the total time and the single slowest request. You can also filter by status class to isolate the 4xx and 5xx responses.
- Does the tool replay network traffic?
- No. It only parses the exported JSON. Nothing in the file is re-requested, and the page makes no network calls of its own with your data.
- Why does it show header names but not their values?
- Because printing a session cookie or bearer token back onto the screen just copies the secret somewhere new. The names are enough to tell you what a request carries and what you need to redact.