HAR file viewer
Drop a .har file to see every network request it captured — sizes, timings, status codes, and third parties — in a sortable, searchable waterfall. No signup.
New to HAR files? Learn what they are and how to export one →
What this HAR viewer shows you
A HAR (HTTP Archive) file is a JSON recording of every request a page made while it loaded. Reading that raw JSON by hand is miserable, so this viewer turns it into a request waterfall you can actually read: each request as a row with its URL, resource type, HTTP status, transfer size, and a timing bar broken into the phases that matter — blocked, DNS, connect, TLS, waiting (TTFB), and receiving.
The table is sortable and filterable. Sort by transfer size to find the megabyte image nobody optimized, by duration to find the request that stalled the page, or by status to surface the 404s and redirects. Filter to just scripts, or just third-party requests, and search by URL to isolate one domain. A capture with thousands of requests stays responsive because the rows are virtualized.
More than a viewer — it tells you what to fix
Most HAR viewers stop at showing you the data. This one also runs a deterministic performance engine over the capture and hands you a ranked list of real problems: render-blocking scripts, oversized assets, missing compression, weak caching, slow third parties, and redirect chains — each with the exact bytes or milliseconds it costs, not a vague grade. A single 0–100 Harpoon Score tells you how the page did overall, and which dimension dragged it down.
Every finding is discovered by the engine from the numbers in your file. The optional AI explanation reads that curated list of findings and turns it into a prioritized, plain-English plan.
Your data stays yours
HAR files can contain sensitive data — cookies, auth tokens, and query strings are all recorded — so treat them with care. When you drop a file here it is analyzed to produce the findings and score. If you want to keep an analysis or share it, create an account; otherwise nothing is saved to your history.
HAR analysis FAQ
How do I open a HAR file?
Drag the .har file onto the drop zone above, or click to browse for it. It opens instantly in your browser as a readable request waterfall — there is nothing to install and no account required.
Is it safe to upload a HAR file?
HAR files can contain cookies, authorization headers, and query-string values, so only share captures you are comfortable with. Here, the file is used to compute the findings and score; the AI explanation is generated solely from those curated findings, never from your raw requests, cookies, or response bodies.
What can I see in the viewer?
Every request the page made, with its URL, resource type, HTTP status, transfer size, and a timing bar split into blocked, DNS, connect, TLS, waiting (TTFB), and receiving phases. You can sort, filter by resource type, search by URL, and jump straight to the slowest or heaviest requests.
Do I need to sign up?
No. Viewing and analyzing a HAR is free and needs no account. Sign up only if you want to save analyses, share a report link, or monitor a page on a schedule.