Chrome Extension · Manifest V3 · No server required

Capture everything.
Miss nothing.

LogLens auto-captures console logs, errors, network & WebSocket frames — including workers & iframes — via Chrome DevTools Protocol.

Install from Chrome Web Store See it in action →

Free forever · Zero data collection · Works offline

LogLens — Log Panel · chrome-extension://loglens/panel.html
LogLens
Capturing
Search… (/regex/ supported)
09:14:32.441
ERRNEW
Uncaught TypeError: Cannot read properties of undefined (reading 'map') — ProductList.tsx:47
09:14:32.218
NET
404 GET https://api.example.com/v2/products?page=1 SLOW 2 341ms
09:14:31.874
WARN
Each child in a list should have a unique "key" prop. ×4
09:14:31.602
NET
200 POST https://api.example.com/v2/auth/refresh · 143ms
09:14:30.887
WS
↑ {"type":"subscribe","channel":"notifications","userId":"u_882f"}
09:14:30.298
LOGWorker
[ServiceWorker] Cache hit for /static/app.chunk.abc12.js
09:14:29.991
NET
200 GET https://api.example.com/v2/analytics/summary?range=30d SLOW 3 102ms
09:14:28.601
ERRNEW
Unhandled Promise Rejection: NetworkError: Failed to fetch
Total 247 · Errors 18 · Net 189 · Targets 3 shop.example.com
Features

Everything DevTools
should have built in.

Six powerful capabilities in one lightweight extension. No config, no server, no telemetry.

Deep Capture via CDP
Attaches to all child targets automatically — Web Workers, Service Workers, cross-origin iframes. Every log line is labeled with its origin.
Worker · iframe · ServiceWorker
Source Map Resolution
Translates minified stack traces back to original file names and line numbers. Built-in VLQ decoder — zero external dependencies.
Built-in VLQ · No libraries
Session Diff
Compare two captured sessions side-by-side. See exactly which errors were fixed and which are newly introduced — perfect for fix-then-verify workflows.
Fixed · New · Regression
Smart Alerts
Triggers a Chrome notification on text/regex pattern match, error spikes, or automatic log export at N errors — keep an eye on issues without staring at the panel.
Pattern · Spike · Auto-export
Persistent Sessions
Every capture session is saved to IndexedDB and survives tab closure or service worker suspension. Browse, search, and export any past session.
IndexedDB · Survives restarts
Error Snapshots
At each error: captures URL, User-Agent, viewport, localStorage, and an optional screenshot. Full reproduction context, no manual note-taking required.
Snapshot · Screenshot · Context cluster
How it works

Up and running
in 30 seconds.

No config files, no accounts, no server. Just install and start capturing.

1
Install & Attach
Click the LogLens icon in your Chrome toolbar, then hit Start capture. LogLens attaches instantly via Chrome DevTools Protocol.
1. Open Chrome Web Store
2. Click Add to Chrome
3. Click the LogLens icon → done
2
Capture Everything
Logs stream in real time — console, errors, network, WebSocket. Workers and iframes are attached automatically. Every event is labeled with its source.
✓ Main page
✓ Web Worker · iframe
✓ Service Worker
3
Analyze & Export
Filter, search with regex, resolve source maps, diff sessions, or export to JSON/TXT. Sessions persist in IndexedDB — come back later anytime.
export shop.example.com_
20260608-091432.json
✓ 247 events · 18 errors
Capabilities

Built for real
debugging workflows.

Every feature is designed around how developers actually debug — not how tools think they should.

Network & WebSocket capture — shop.example.com
Full HTTP/HTTPS request capture
Status code, method, URL, timing, and on-demand response body retrieval for every request — including those made by workers.
WebSocket frames (sent & received)
Every WS message is captured and displayed with direction (↑ send / ↓ receive), making real-time protocol debugging straightforward.
Slow request detection
Requests exceeding your configured threshold are highlighted in amber with a SLOW badge. Threshold is configurable per session.
Duplicate grouping & noise reduction
Identical errors collapse to ×N
Same error appearing 50 times? It shows as one row with a count badge. Toggle grouping on/off instantly to switch between views.
NEW badge for first-occurrence errors
Any error appearing for the first time in the current session gets a NEW badge so you never miss a regression hiding in the noise.
Context cluster per error
Each error stores the 8 events that occurred just before it. Open the context drawer to understand what led to the failure.
Source map resolution — VLQ decoder built-in
Before — Minified
TypeError: Cannot read
  properties of undefined

at t (main.a4f8c2.js:1:8921)
at e (vendor.b2c31d.js:1:443)
at n.render (app.min.js:1:201)
After — Resolved →
TypeError: Cannot read
  properties of undefined

→ ProductList.tsx:47:12
→ ReactFiberHooks.js:721
→ App.tsx:18:5
Click the 🗺 map button on any error row. LogLens fetches the .map file and resolves the full stack back to original sources — no build tool integration required.
Session diff — Before fix vs. After fix
Before fix
312 lines · 23 errors
After fix
247 lines · 5 errors
Diff result
✓ TypeError: Cannot read properties of undefined
✓ NetworkError: Failed to fetch (unhandled rejection)
✓ 404 GET /api/v2/products — fixed endpoint
✗ 404 GET /api/v2/recommendations — not yet deployed
✗ Warning: validateDOMNesting — new component
Why LogLens

Built different.

LogLens fills the gaps that standard DevTools leaves open — especially for complex, multi-target apps.

0
Log lines buffered in memory
0
Capture targets in parallel
0kb
External dependencies
0%
Local — zero data leaves your browser
LogLens vs. built-in DevTools
Capability DevTools LogLens
Capture worker & iframe logsPartial✓ Full
Persist logs across page reloads✗✓
Compare two capture sessions✗✓
Alert on custom error pattern✗✓
Capture error context automatically✗✓
Export logs to JSON / TXTHAR only✓ JSON + TXT

Ready to see what your
app is really doing?

Install LogLens in seconds. No account, no server, no config. Just open Chrome and start capturing.

Add to Chrome — It's Free
Free forever
Zero data collection
Works offline
Open source