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How to Disable Unnecessary Image Sizes in WordPress

Last updated on August 7, 2026

Key Takeaways

• Single toggle, no nested options

• Quick WordPress optimization with one click

• Does not affect core WordPress functionality

• Reversible (disable to restore default behavior)

Why You Need It

WordPress generates multiple image sizes (thumbnail, medium, medium_large, large) by default. If you don’t use certain sizes, they consume disk space unnecessarily.

How to Enable this Feature

Step 1: Navigate to Settings

Click into the Classic Monks plugin settings, then the Performance tab, Media Enhancements subtab.

Step 2: Enable the Feature

Toggle on the feature.

Disable unnecessary image sizes

Step 3: Save and Test

Click Save Changes. Test on the frontend.

Common Use Cases

Sites with custom sizes

If you’ve registered custom sizes and don’t need the default sizes, disabling them saves disk space.

Performance optimization

Fewer image sizes mean fewer database entries and faster backups.

Developer integration

This feature registers 1 WordPress hook in media-functions.php:

Filters:

  • intermediate_image_sizes calls cm_disable_unwanted_image_sizes() (Removes selected intermediate image sizes)
// Hooked in media-functions.php
add_filter( 'intermediate_image_sizes', 'cm_disable_unwanted_image_sizes' );

The feature modifies WordPress behavior by registering or removing hooks. Disabling it reverses those changes and WordPress returns to its default behavior.

Before you enable this feature

  1. Test on staging first to verify no conflicts with your theme or other plugins
  2. Check dependent plugins that may rely on the functionality being modified
  3. Monitor after enabling for any unexpected behavior on the frontend

How it works under the feature

This feature runs during the WordPress initialization phase. When enabled, its PHP code registers hooks that modify specific WordPress behaviors. The changes are non-destructive and reversible.

No database schema changes are made. The feature state is stored as a boolean value in the wp_options table and can be toggled at any time from the admin settings.

Troubleshooting

Cause: The toggle is off, or a caching plugin is serving the old page.
Fix: Verify the toggle is on. Clear all caching layers.

Cause: Another plugin depends on the functionality that this feature disables.
Fix: Disable this feature if it breaks another plugin.

Sumit Your Ideas or Feature Requests

All submissions go through a manual review, so not every idea will be published. That said, the most upvoted ideas are given priority on our official roadmap.Please check if your idea already exists before submitting. If you find it, simply upvote it to help us prioritize it.