Disabling automatic JPEG compression in WordPress using PHP

By default, WordPress automatically compresses JPEG images to 90% quality when you upload them. While this helps reduce file size, it can noticeably lower image quality—especially if the image was already optimized before upload. On ruachost.com, you can disable this automatic compression using a simple PHP snippet.

Why Disable JPEG Compression?

• Preserve original image quality.

• Prevent double compression of already optimized images.

• Ensure sharper visuals for photography or design‑focused sites.

Steps to Disable JPEG Compression

1. Log in to WordPress with an administrator account.

2. In the dashboard, go to Appearance → Theme Editor.

3. Select your active theme and open the functions.php file.

4. Add the following code snippet at the end of the file:

   // Disable automatic JPEG compression in WordPress
   add_filter('jpeg_quality', function($arg){ return 100; });
   

   • 100 ensures images are saved at full quality.

   • You can adjust the value (0–100) if you prefer a custom compression level.

5. Save the file.

6. Upload a new JPEG image → WordPress will now keep it at the specified quality.

Important Notes

• Always back up your theme before editing functions.php.

• Use a child theme to preserve changes during updates.

• This change only affects new uploads. Existing images remain compressed.

• To re‑apply settings to old images, use the Regenerate Thumbnails plugin.