HAR File Analyzer
Analyze HAR files to find slow requests and large assets
What is HAR File Analyzer?
A HAR analyzer parses the network log exported from your browser and summarizes request count, total response body size, failure count, and timing distribution, with sorting by duration or size to pinpoint bottlenecks. The file is parsed inside your browser and never uploaded.
How to use HAR File Analyzer
- 1Right-click in your browser's Network panel and choose Save all as HAR.
- 2Select that file in this tool.
- 3Sort by duration or size to find the slowest and heaviest requests.
- 4Delete the HAR file once you are done with it.
Common errors and how to fix them
| Symptom | Cause | Fix |
|---|---|---|
| A HAR file gets shared in a group chat | A HAR records complete request headers, including Cookie and Authorization. | Enable the sanitize option at export time if your browser offers one, or strip the sensitive fields by hand before sharing. |
Frequently asked questions
Why is a HAR file considered sensitive?+
It contains the full request headers for every request, and the Cookie and Authorization values in there are enough for someone else to impersonate your logged-in session. Sending a HAR to a colleague for debugging is effectively lending them your account, which is why this tool parses it locally instead of uploading it.
What phases does the timing figure include?+
It covers queueing, DNS resolution, the TCP connection, the TLS handshake, sending the request, waiting for the response (TTFB), and downloading the content. A high total does not necessarily mean a slow server; it can just as easily come from connection setup or concurrency queueing, so read it alongside the phase-by-phase waterfall in the Network panel.
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