OpenAnyFile
Works
Viewing, inspecting and verifying. You get a collapsible, syntax-coloured tree you can expand node by node. File details, exact byte size and the detected signature are always shown.
How to open a .har file
If double-clicking a HAR file did nothing useful, that is normal: the format is fine, your operating system just has no default application registered for it. This page explains the format and gives you a way to read one immediately.
What is a .har file?
HTTP Archive is a data & config format developed by W3C Web Performance WG, first appearing in 2007. It is normally produced by Chrome DevTools, Fiddler.
A JSON recording of every network request in a session. It captures headers and cookies verbatim, so HAR files routinely leak live auth tokens.
| Full name | HTTP Archive |
|---|---|
| File category | Data & config |
| MIME type | application/json |
| Magic bytes (file signature) | 7B ({) |
| Developer | W3C Web Performance WG |
| Introduced | 2007 |
| Usually created by | Chrome DevTools, Fiddler |
| OpenAnyFile engine | JSON tree viewer |
| Opens without upload | Yes — parsed locally in your browser |
Open a .har file in your browser
OpenAnyFile routes .har to its JSON tree viewer, which parses a collapsible, syntax-coloured tree you can expand node by node.
- Open the OpenAnyFile opener in this browser — nothing to download or sign up for.
- Drag your .har file onto the drop zone, click to browse for it, or paste it with Ctrl+V.
- The extension is detected and the file is handed to the JSON tree viewer.
- Your HAR opens on its own viewer page: a collapsible, syntax-coloured tree you can expand node by node.
- Use fullscreen for a closer look, or download the file back out unchanged. Nothing is transmitted anywhere — the parsing happens in your own browser process.
What you can and cannot do with it here
Does not work
Editing and re-saving. OpenAnyFile is a reader, not an editor — for changes you still need special software or an equivalent.
Why your {ext} file is never uploaded
Most online viewers work by sending your file to their server, processing it there, and leaving a copy behind on infrastructure you do not control. OpenAnyFile does not. Your .har file is read through the browser's local File API and decoded by JavaScript and WebAssembly running on your own machine. There is no upload step and no server-side copy — open your browser's network tab while you do it and watch: the file never appears.
Frequently asked questions about HAR files
Can I open a .har file without installing special software?
Yes. OpenAnyFile's JSON tree viewer runs in your browser, so you can read a HAR file with nothing installed. You get a collapsible, syntax-coloured tree you can expand node by node. For full editing you still need the original application — this is a viewer, not an editor.
How can I check a file really is a HAR file?
Look at the first bytes rather than the extension. A genuine HAR begins with 7B ({). Opening the file in OpenAnyFile shows that signature in the file-details panel, so a file renamed to .har by mistake is easy to spot.
Is it safe to open a HAR file online?
With OpenAnyFile, yes, because nothing is uploaded. The file is read locally through your browser's File API and never leaves your device, so there is no server copy to leak, log or retain. That matters most for the kind of file people are least willing to hand to a random converter site.
What is a .har file, exactly?
HTTP Archive — an application/json format created by W3C Web Performance WG since 2007. A JSON recording of every network request in a session. It captures headers and cookies verbatim, so HAR files routinely leak live auth tokens.
Does the same viewer handle formats related to HAR?
Yes — the same engine also opens .json, .geojson, .jsonl, so you can compare related files without switching tools.
Related formats
These open with the same engine, so if you have one of these sitting next to your .har file, it will open too: