network-logger
📡 Network Logger – HAR Exporter
Capture browser network requests across all tabs and export them as a HAR file — without opening DevTools.
What it does
Network Logger attaches Chrome’s built-in DevTools Protocol (CDP) to your browser tabs and records every HTTP/HTTPS request — including full request and response bodies — then exports everything as a standard HAR 1.2 file that opens directly in Chrome DevTools, Charles, Fiddler, or any HAR viewer.
Key difference from DevTools: DevTools must be open and on the correct tab before the request fires. Network Logger captures traffic from all tabs the moment you click Start, even if DevTools has never been opened.
Features
- 🔴 One-click recording — Start/Stop from the extension popup
- 📦 Full bodies — Request payloads (POST/PUT) and response bodies via CDP
- ⬇ Standard HAR 1.2 — Loads in Chrome DevTools, Charles Proxy, Fiddler, Postman
- 🔒 100% local — No server, no analytics, no data ever leaves your device
- ⚡ Zero page impact — No script injection, no DOM modification
- 🕐 Precise timings — Send, wait (TTFB), receive in milliseconds
- 🌐 All tabs — Captures traffic across every open tab simultaneously
- 💾 Memory-safe — Capped at 50,000 entries; cleared on Stop or Close
Installation
From the Chrome Web Store (recommended)
- Visit the Chrome Web Store listing
- Click “Add to Chrome”
- Click “Add extension” in the confirmation dialog
- The 📡 icon will appear in your Chrome toolbar
How to use
Step 1 — Start recording
Click the 📡 icon in your Chrome toolbar to open the popup, then click Start Recording.
A yellow “Chrome is being debugged” bar will appear — this is Chrome’s built-in security notification that the DevTools Protocol is active. It disappears automatically when you stop recording.
Step 2 — Browse normally
Use your browser as usual. The popup shows a live counter of captured requests. You can close the popup — recording continues in the background.
Step 3 — Stop recording
Click Stop Recording in the popup. The debugger detaches from all tabs and the yellow bar disappears.
Step 4 — Export as HAR
Click Export as HAR. A file named network-log-YYYY-MM-DDTHH-MM-SS.har is saved to your Downloads folder.
Step 5 — Load in DevTools (optional)
- Open Chrome DevTools with
F12orCmd+Option+I - Click the Network tab
- Drag-and-drop the
.harfile onto the request list - All requests appear with full headers, bodies, and timing data
What’s captured in the HAR
| Field | Details |
|---|---|
| Request line | Method, full URL, HTTP version, query params |
| Request headers | All headers incl. Authorization, Cookie |
| Request body | POST/PUT payloads — JSON, form data, binary |
| Response status | HTTP status code and status text |
| Response headers | All response headers incl. Set-Cookie |
| Response body | Full content — text, JSON, HTML; binary as base64 |
| Timing | Send, wait (TTFB), receive in milliseconds |
| Protocol | HTTP/1.1, h2, h3 per request |
Permissions
| Permission | Why it’s needed |
|---|---|
debugger |
Attaches CDP to observe network traffic and retrieve response bodies. Active only while recording. |
tabs |
Enumerates open tabs so the debugger can attach to each one. |
downloads |
Saves the .har file to your local disk. |
storage |
Persists only the on/off state across service worker restarts. No user data stored. |
offscreen |
Chrome MV3 requirement to perform anchor-element download preserving .har extension. |
<all_urls> |
Allows the debugger to attach to tabs on any domain. No script injection; no DOM reads. |
⚠️ Security notice
HAR files contain passwords, session tokens, API keys, cookies, and other sensitive data transmitted over the network. Do not share HAR files publicly or with untrusted parties without scrubbing sensitive values first.
FAQ
Why does a yellow bar appear when I start recording? This is Chrome’s built-in security notification for any extension using the DevTools Protocol API. It cannot be suppressed — it’s intentional browser behavior. It disappears automatically when you stop.
Does this send my data anywhere? No. All data stays in your browser’s memory. The extension makes zero outbound network requests. Data is discarded when you clear or close the browser.
Why can’t I see some response bodies? Some responses aren’t bufferable by CDP: very large streaming responses, WebSocket frames, Server-Sent Events, and some service-worker-cached responses. Headers and timing for these are still captured.
What Chrome version is required?
Chrome 116 or later (uses Manifest V3 + chrome.offscreen API).
Is it compatible with other HAR tools? Yes — HAR 1.2 spec-compliant. Works with Chrome DevTools, Firefox DevTools, Charles Proxy, Fiddler, Postman, Google HAR Analyzer, and HAR Viewer.
Privacy
All captured data is stored in-memory only and is never transmitted to any server. See the full Privacy Policy.
The use of information received from Chrome APIs adheres to the Chrome Web Store User Data Policy, including the Limited Use requirements.
Contributing
Please open an issue before starting large changes.
License
MIT — free to use, modify, and distribute.
Chrome Web Store · Website · Privacy Policy · Report an Issue