Reading Your Suspended-Tab Statistics

## Why it matters

Numbers matter when you're trying to understand whether a tool is working. The stats panel gives you three things: a snapshot of what's happening right now, a running total for this browser session, and a breakdown of why some tabs aren't being suspended (the exclusions). If Scalpel is quiet and you're not sure whether it's actually saving you memory, the stats panel shows proof. If you've got a hundred tabs open and only thirty are suspended, the panel tells you which sites are taking up the most suspended memory, useful if you're trying to decide which never-suspend list entries might be overkill.

## How it works

The stats panel lives in Scalpel's popup and tracks data in chrome.storage.session, a Chrome API that holds per-session state (emptied each time the browser closes). Here's what it records and why.

Freed now is a snapshot: how many tabs are currently suspended right now, in this window, plus an estimated memory total (85 MB per tab as a rough average). This updates after every suspend or restore action.

This session is cumulative: the total number of tabs you've suspended since the browser started. If you suspended ten tabs this morning and eight more just now, it shows eighteen.

Protected right now breaks down why other tabs aren't suspended. It lists:

• Pinned tabs (the tiny icons at the left of the tab strip, which people usually want to keep awake)
• Audible tabs (currently playing sound)
• Tabs with unsaved form input (a text field where you've typed something but not submitted)
• Sites on your never-suspend list

Top sites shows which domains have contributed the most suspended memory. If you've suspended thirty tabs and half of them are from Slack, that row shows Slack with the highest count.

## What does not matter

The stats don't track across browser sessions. When you close Chrome and reopen it, the counter resets to zero. That's by design: the tally is for "this session," not lifetime. If you want a total, you'd need to use browser's own diagnostics (like chrome://discards or the Task Manager), which are meant for users and developers, not extensions.

The 85 MB estimate isn't gospel. A simple static article might use 15 MB when suspended; a complex web app might use 200 MB. Scalpel uses 85 MB as a reasonable average. If you want to know the real number for a specific tab, open Chrome's Task Manager (Shift+Esc on Windows/Linux, Cmd+Shift+Esc on Mac) and watch the memory column before and after you suspend. That's the ground truth.

The stats panel doesn't affect the extension's behaviour. Turning the stats panel on or off doesn't change when tabs are suspended or restored. It's observation only.

## Code example

Behind the scenes, Scalpel stores the stats like this:

// Save current session stats to chrome.storage.session
const stats = {
  freedNow: 12,
  estimatedMemory: 12 * 85, // 1020 MB
  thisSession: 47,
  protected: {
    pinned: 3,
    audible: 1,
    unsavedInput: 2,
    neverSuspendList: 5
  },
  topSites: [
    { hostname: "slack.com", count: 8 },
    { hostname: "github.com", count: 5 },
    { hostname: "mail.google.com", count: 4 }
  ]
};

chrome.storage.session.set({ sessionStats: stats });

// Retrieve stats
chrome.storage.session.get("sessionStats", (result) => {
  console.log(result.sessionStats);
});
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Every time a tab is suspended or restored, Scalpel updates these numbers and the UI re-renders.

## How Scalpel shows it

Open Scalpel's popup and click the stats icon (or toggle the "Show stats" option in settings). The panel expands to show:

1. A card at the top with "Freed now: X tabs (~YYY MB)"
2. A running counter: "This session: ZZ tabs suspended total"
3. A breakdown of protected tabs: pinned (count), audible (count), unsaved input (count), never-suspend list (count)
4. A "Top sites" list showing which domains you've freed the most

If the stats panel is off, you won't see this data in the popup. But the extension is still counting in the background; it'll just be invisible until you turn the panel on.