Managing Tabs and Scores with Chromium's Discards Page

This article explains how to use the built-in chrome://discards diagnostic page in the Chromium web browser to monitor and manage system memory. It details how users can inspect tab reactivation scores to understand which tabs the browser prioritizes and provides step-by-step instructions on how to manually discard active tabs to instantly free up RAM.

Accessing the Diagnostic Page

To access the tool, open a Chromium-based browser, type chrome://discards into the address bar, and press Enter. This opens the "Discards" tab, which displays a comprehensive data table listing every currently open tab across all of your browser windows.

Inspecting Tab Reactivation Scores

Chromium uses an internal machine learning system called the Tab Ranker to calculate how likely you are to return to a background tab. This helps the browser decide which tabs to keep in memory and which ones to unload when your computer runs low on RAM. You can inspect these metrics directly on the page:

  • Locate the Reactivation Score: Look for the "Reactivation Score" column in the main table. This column displays a numerical value representing the probability that you will reactivate the tab during your current browsing session.
  • Interpret the Values: A higher reactivation score means the browser predicts you will return to the tab soon. A lower score indicates the tab is likely forgotten. Note that active tabs or very recently opened tabs may not display a score until they have been in the background for a sufficient amount of time.
  • Check the Utility Rank: The first column on the left, "Utility Rank," sorts all open tabs from most important (Rank 1) to least important. This rank is heavily influenced by the reactivation score, alongside the "Site Engagement Score" and current tab activity (such as playing audio). Tabs at the very bottom of this list have the lowest reactivation scores and will be the first ones the browser automatically discards when system memory is depleted.

Manually Discarding Tabs

You do not have to wait for your computer to run out of memory for Chromium to unload unused tabs. You can use the diagnostic page to manually discard tabs and free up RAM immediately:

  • Find the Actions Column: Scroll to the far right side of the diagnostic table to find the "Actions" column.
  • Trigger an Urgent Discard: Click the [Urgent Discard] link next to the tab you wish to unload. The browser will immediately purge that tab's processes and data from your system memory.
  • Accessing Discarded Tabs: Discarding a tab is not the same as closing it. A manually discarded tab remains visible on your browser's top tab strip. When you click on the tab again, Chromium will simply reload the webpage from where you left off.
  • Overriding Protections: The "Can Discard" column shows whether a tab meets the browser's safe criteria for automatic unloading (for example, tabs playing audio or containing unsaved form data are usually protected and marked as false). Clicking [Urgent Discard] bypasses these safety checks and forces the tab out of memory regardless of its current state.
  • Locking Important Tabs: If you notice a tab has a low reactivation score and is at risk of being discarded, you can protect it. Locate the "Auto Discardable" column for that tab and click the toggle to switch it from a checkmark to an X. This prevents the browser from automatically discarding the tab until you close it or restart the browser.