HAR Viewer
Open HAR files online. Request table with status colors, sorting and filtering, headers, response body preview and a timing waterfall — parsed locally, nothing is uploaded.
What is a HAR file?
HAR (HTTP Archive) is a JSON format that records the network activity of a browser or app: every request with its URL, headers, query parameters, status, sizes, timings and response bodies. Chrome DevTools, Firefox and most proxy tools can export it.
How do I open a .har file online?
Drag the file onto the drop zone or click to choose it. The file is parsed instantly and shown as an overview plus a request table — no account, no installation and no upload involved.
Is my captured traffic uploaded anywhere?
No. The HAR file is parsed entirely inside your browser with JavaScript. Requested URLs, headers, cookies and response bodies never leave your device, and the viewer keeps working offline once the page has loaded.
What do the status colors mean?
Green marks successful 2xx responses, blue redirects (3xx), orange client errors (4xx) and red server errors (5xx). The same colors are used in the table, the waterfall and the timing bars so problems stand out immediately.
Can I search or sort the requests?
Yes. The search box filters live by URL or domain, and clicking the Status, Size or Time column headers sorts the table in ascending or descending order.
What does the response body preview show?
JSON bodies are pretty-printed with lightweight syntax coloring, text and HTML bodies are shown as-is, image responses are rendered inline from their base64 data, and binary or missing bodies show a size hint. Bodies larger than 1 MB are truncated to keep the page fast.
How do I read the waterfall chart?
Each row is one request drawn as a bar positioned by its start time relative to the total capture duration, so you can see which requests ran in parallel, which one blocked the rest and where the slowest time went.
What happens with very large HAR files?
Files over 50 MB or more than 5000 entries are truncated to the first requests with a clear notice, which keeps parsing quick while still showing the most relevant beginning of the capture.
Which tools produce HAR files this viewer understands?
Any export following the HAR 1.2 specification: Chrome and Edge DevTools, Firefox Network Monitor, Safari Web Inspector, Fiddler, Charles Proxy, mitmproxy and most load-testing tools.
How to Use HAR Viewer
This HAR viewer opens HTTP Archive (.har) files exported from Chrome DevTools, Firefox or any proxy tool, and lays out the whole capture as an overview, a sortable request table, expandable row details and a timing waterfall. Parsing happens entirely in your browser — captured URLs, headers and response bodies never leave your device.
- Drop a .har file onto the upload area or click "choose a file"; no capture handy? Click "Load sample HAR" to explore with demo traffic.
- Read the overview cards first: total requests, transferred size, total duration and the top 5 domains by request count with bar lengths proportional to volume.
- Use the request table: statuses are color-coded (green 2xx, blue 3xx, orange 4xx, red 5xx) and each row shows method, type, size and duration.
- Click the Status, Size or Time column headers to sort ascending or descending; type in the search box to filter by URL or domain.
- Click any row to expand it: query parameters, request headers, response headers and a response body preview — JSON is pretty-printed with coloring, images render inline, oversized bodies are truncated with a notice.
- Check the waterfall below the table: each bar sits at its start time relative to the total capture, making parallel requests and slow outliers easy to spot.
To capture a HAR in Chrome, open DevTools, go to the Network tab, reload the page, then right-click the request list and choose "Save all as HAR" — the file stays on your machine the whole time.
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