Network Throttler

About

Test how your site feels on a slow connection without leaving the page you're working on. Throttle one tab or several at once, all from a single side panel that stays open while you browse.

Features

- One-click presets: Offline, 3G, Slow 4G, Fast 4G (matching Chrome DevTools)
- Custom latency (ms), download and upload (kbps) via segmented mode switcher
- Multi-tab control: throttle several tabs at once and manage them all from one place
- Live chip list of every throttled tab: click to jump to it, click × to stop just that one, or "Stop all" to clear them in one shot
- Optional auto-refresh on apply, so the new conditions take effect immediately
- Tab indicator showing which tab you're currently controlling
- Stop Throttling action only appears when there's actually something to stop, so no clutter when idle
- Light and dark mode (follows your system preference)
- Works per-tab, so other tabs are completely unaffected

How it works

Uses Chrome's built-in DevTools Protocol (the same mechanism DevTools uses) to emulate network conditions on a per-tab basis. Each throttled tab gets its own debugger session, so you'll see Chrome's standard "Network Throttler started debugging this browser" banner on tabs that are actively being throttled. This is normal and disappears when you stop throttling that tab.

Privacy

No analytics. No tracking. No network requests to any server. Nothing leaves your browser. Your auto-refresh preference is stored locally in chrome.storage.local, and the list of currently-throttled tabs lives in chrome.storage.session (cleared when you close the browser).