How Much Memory Does Suspending a Tab Save?

## Why it matters

You've got thirty tabs open and your laptop is crawling. You want to know: if I suspend half of these, will it actually help? Chrome's Task Manager shows you memory per tab, but the numbers are noisy: some tabs use 50 MB, others use 500 MB. Scalpel gives you a round number: 85 MB per suspended tab, as a rough average. It's not precise, but it's enough to tell you roughly how much memory you'll get back. Suspend ten tabs, get back about 850 MB. Suspend thirty, get back about 2.5 GB. That matters when your browser is using 5 GB and your machine only has 8 GB total.

## How it works

When you suspend a tab with chrome.tabs.discard(), Chrome tears down the renderer process for that page. The renderer process is where the page's JavaScript runs, where the DOM lives, where images and stylesheets are cached, and where browser state like localStorage and the heap are stored. Tearing it down frees all of that. The tab URL, title, favicon, and scroll position are kept in a lightweight state by the browser itself.

The 85 MB figure is an educated guess based on Chrome's own data and observations from suspension tool maintainers. A typical modern web page (blog post, news article, simple app) uses somewhere in that ballpark. A complex single-page application (Gmail, a design tool, a spreadsheet editor) might use 200–400 MB or more. A minimal page (a plain HTML file, a stripped-down mobile site) might use only 20–30 MB. The variation is huge.

Scalpel doesn't have a system.memory permission (Chrome doesn't grant such broad access to extensions), so it can't measure the exact memory of each page. Instead, it uses the same rough estimate for every tab. If you want to see the real number for a specific tab, Chrome's Task Manager is where to look.

## What does not matter

Suspension doesn't usually save battery. This is a common myth. Suspending a tab saves RAM and reduces CPU usage in the renderer process, but battery drain is mostly tied to screen brightness, CPU load from active work, and network activity. If you're not looking at a tab, it's probably not draining much battery anyway. RAM usage can sometimes affect battery (if you're swapping to disk), but most modern laptops with 8 GB or more won't hit that scenario. Memory savings matter if you're running out of RAM, not if you want to save battery.

Not all 85 MB is real. Memory accounting is complicated. Some of that 85 MB might be shared libraries, code caches, or memory that would persist even if the tab were open. Real memory pressure depends on your entire system state and Chrome's internal allocation strategies. The 85 MB is a useful rule of thumb, not a forensic measurement.

Suspension doesn't clear cookies or site data. When you suspend a tab, its local storage, service workers, session storage, and cookies all survive. They'll be restored when the tab reloads. If you want to truly clear a site's data, you need to clear site data manually from Chrome's settings, not suspend the tab.

## Code example

Here's how you'd measure real memory usage in Chrome's Task Manager (the script is for reference; you can't run this from an extension, but you can observe the numbers manually):

// Open Chrome's Task Manager to see this in action
// Shortcut: Shift+Esc (Windows/Linux), Cmd+Shift+Esc (Mac)

// Before suspending, Chrome Task Manager shows (example):
// Tab: "My Article" - 156 MB

// After suspending the tab:
chrome.tabs.discard(tabId);

// Task Manager now shows (example):
// Tab: "My Article" (Suspended) - 2 MB

// The difference (about 154 MB in this example) is what that tab freed.
Copy

Open Task Manager, find the tab you're interested in, and watch the memory number before and after you suspend it. Repeat with several tabs to get a sense of the variation. You'll see why 85 MB is just an average.

## How Scalpel shows it

If you turn on the stats panel in Scalpel's settings, the popup displays an estimated memory saving. It shows something like "Freed now: 12 tabs (~1020 MB)" based on the formula: (number of suspended tabs) × 85 MB. This is a guide to help you understand the scale of what you've freed, not a guarantee. Actual memory savings might be significantly higher or lower depending on which sites you suspended.

The stats panel also shows a "Top sites" breakdown. If you've suspended tabs from five different sites, it groups them and shows which domain is using the most estimated memory. That's useful if you're trying to decide which sites should go on your never-suspend list (because they're important and you're keeping them awake anyway).