How to Fix “This Webpage Is Using Significant Memory” in Safari on Mac

Browsing your favourite websites in Safari on macOS only to have an alarming yellow notification banner drop down beneath the address bar stating “This webpage is using significant memory. Closing it may improve the responsiveness of your Mac” is a frustrating distraction. In severe cases, the browser tab freezes entirely, causing your fans to ramp up and making scrolling jerky.

Safari displays this warning when a single browser process consumes memory far beyond standard web thresholds (typically in excess of 1GB to 2GB for a single tab). The issue is rarely a hardware inadequacy on your Mac; instead, it is triggered by unoptimised client-side JavaScript memory leaks, heavy tracking scripts, auto-playing video streams, unshielded WebGL canvas elements, or incompatible third-party Safari extensions. This tutorial details how to eliminate the warning banner and optimise Safari’s memory footprint.

Method 1: Identify and Remove Leaking Website Data for the Domain

Stale IndexedDB records, local storage blobs, and corrupted cookie files can force Safari’s WebKit engine to continuously rebuild Document Object Model (DOM) trees in memory.

1. Open Safari on your Mac.
2. Click Safari in the top menu bar and select Settings… (or Preferences…).
3. Select the Privacy tab.
4. Click the Manage Website Data… button.
5. In the search box in the upper-right corner, enter the domain name of the webpage triggering the memory warning.
6. Select the website from the filtered search results.
7. Click Remove, followed by Done.
8. Close Settings, reload the webpage, and monitor whether memory consumption normalises.

Method 2: Empty the Safari Browser Cache via Developer Tools

Accumulated temporary script files and media cache objects can saturate WebKit process memory allocations.

1. If the Develop menu is not visible in your top menu bar: go to Safari > Settings > Advanced and check “Show features for web developers” (or “Show Develop menu in menu bar”).
2. Click Develop in the top menu bar.
3. Select Empty Caches (or press Option + Command + E).
4. Quit Safari completely by pressing Command + Q.
5. Relaunch Safari and reopen your tab.

Method 3: Audit and Disable Problematic Safari Extensions

Third-party extensions—especially shopping assistants, ad blockers with massive filter lists, or automated translation tools—inject content scripts into every loaded frame, multiplying memory usage significantly.

1. Open Safari > Settings > Extensions.
2. Uncheck all enabled extensions to disable them temporarily.
3. Reload the webpage that produced the memory warning.
4. If the warning banner disappears, re-enable your extensions one by one, refreshing the page after each, to identify the extension responsible for the memory overhead.
5. Update or uninstall the offending extension.

Method 4: Toggle Advanced Tracking and Fingerprinting Protection

Modern Safari releases include built-in protection against tracking and digital fingerprinting scripts. Enabling strict tracking protection prevents bloated analytical tracking scripts from running memory loops.

1. Open Safari > Settings > Advanced.
2. Locate the option labelled “Use advanced tracking and fingerprinting protection”.
3. Set the dropdown to in all browsing (rather than private browsing only).
4. Return to the Websites tab in Settings, click Auto-Play in the left sidebar, and set the website to “Never Auto-Play” to prevent runaway background video buffers from consuming memory.

Safari Webpage Memory Diagnostics Reference Table

Use the matrix below to assess memory warnings in Safari:

Observed Warning Context	Probable Root Cause	Recommended Solution
Warning on social feeds (Facebook, Twitter/X)	Infinite scroll JavaScript DOM node accumulation	Refresh tab periodically to flush DOM tree
Warning appears across multiple tabs simultaneously	Bloated ad-blocker extension injecting heavy scripts	Disable extension; switch to lightweight content blocker
Warning on complex web apps (Canva, Google Sheets)	High-resolution graphics / WebGL canvas rendering	Close background apps; disable unused browser extensions
Tab reloads automatically with “A problem occurred”	WebKit process exceeded hard memory ceiling	Empty Caches (Opt+Cmd+E) and clear website data
Warning accompanied by high Mac fan noise	Runaway JavaScript loop in cryptocurrency / ad script	Enable “in all browsing” tracking protection in Advanced

Inspecting Tab Memory in Safari Web Inspector

For advanced diagnosis, inspect the exact memory allocation of the offending webpage. With the page open, right-click anywhere on the webpage and select Inspect Element. Click the Timelines tab at the top of Web Inspector, enable the JavaScript & Events and Memory checkboxes, and click the Record button. This visualizes heap allocations in real time, pinpointing whether images, JavaScript closures, or DOM elements are causing the memory bloat.