DevTools.
In Your Sidebar.
ALT-DEV TOOLS brings a full-featured DevTools panel directly into Chrome's side panel — Elements, Console, Network, Sources, Application, Performance & Device emulation, all without opening F12.
Free forever for core panels · Pro via one-time activation key
Free Panels
Powerful out of the box. No account or payment needed.
Elements
Inspect and live-edit the DOM. View CSS rules, computed styles, and the box model.
Console
Full JavaScript console. Evaluate expressions, see logs, warnings, and errors.
Network
Monitor HTTP requests, inspect headers, bodies, cookies, and WebSocket frames.
Unlock the Full Suite
One activation key. All Pro panels. Forever.
Sources
Browse all page scripts and stylesheets. View and search source files inline.
Application
Manage localStorage, sessionStorage, and cookies with full read/write/delete support.
Performance
Load time, FCP, DOM timings, JS heap, resource waterfall, and live FPS meter.
Device
Proper viewport emulation via Chrome's DevTools Protocol. Media queries respond correctly.
How it works
Install
Add ALT-DEV TOOLS to Chrome. Free instantly — no account required.
Get Pro (optional)
Purchase a one-time license. An activation key is emailed to you.
Activate
Paste your key in the extension's License settings. All Pro panels unlock instantly.
Ready to ditch F12?
Free forever for core features. Pro unlocks Sources, Application, Performance & Device emulation.