Back to Community
Home / Community / Plugin → Ewww image optimizer

Troubleshooting EWWW Image Optimizer: Why Your Bulk Optimization Stalls or Fails

46 threads Sep 10, 2025 Plugin → Ewww image optimizer

Content

If you're using EWWW Image Optimizer and find that the bulk optimization process stalls, fails with an error, or doesn't process all your images, you're not alone. This is a common issue reported by users, often stemming from server limitations, configuration conflicts, or the sheer volume of images. This guide will walk you through the most common reasons for these failures and the steps you can take to resolve them.

Why Bulk Optimization Fails or Stalls

Based on community reports, bulk optimization issues typically occur for a few key reasons:

  • Server Timeouts: The PHP max_execution_time limit can interrupt long-running optimization scans. One user confirmed their limit was set to 900 seconds, yet the scan still timed out.
  • Parallel Optimization Conflicts: Some users have reported that enabling the 'Parallel Optimization' advanced setting can cause images to become stuck with an "In Progress" status. Disabling this feature resolved the issue for them.
  • Large Batches of Images: Optimizing a site with thousands of images and their numerous resizes can put a significant load on the server, leading to interrupted processes. The plugin is designed to work in batches to avoid this, but sometimes it needs help.
  • Third-Party Plugin Conflicts: Integration issues with other plugins, especially those that offload media to external storage like Azure or S3, can prevent images from being optimized or re-uploaded correctly. One user identified a conflict with the Windows Azure Storage plugin that caused a 409 error.
  • Basic Authentication: If your site uses HTTP Basic Auth, the plugin's background optimization process will be disabled because the server cannot send a request to itself without the proper credentials.
  • Database Issues: After reinstalling the plugin, missing database tables (like wp_ewwwio_images and wp_ewwwio_queue) can cause errors and prevent the bulk optimizer from recognizing existing images.

How to Fix Bulk Optimization Issues

1. Address Server Timeouts and Resources

While increasing your PHP max_execution_time is a good first step, it may not always be sufficient. The plugin is designed to work in short batches to circumvent this limit. If scans are timing out, ensure you are using the latest version of the plugin, as updates often include improvements to this batching logic.

2. Toggle Parallel Optimization

If images are stuck "In Progress," navigate to the plugin's Advanced Settings and try disabling the Parallel Optimization option. This has been a confirmed solution for some users experiencing this specific hang-up.

3. Check for Plugin Conflicts

Conflicts with other plugins are a common source of problems. If you are using a storage plugin like Windows Azure Storage or Offload Media Lite, be aware that manual offloading can cause path retrieval errors ("Could not retrieve file path"). For S3 users, the 'EWWW Image Optimizer' team suggests using their dedicated S3 Image Optimizer tool to handle images uploaded outside of WordPress. Temporarily disabling other plugins can help you identify if a conflict is causing the bulk optimizer to fail.

4. Understand What Bulk Optimization Does

It's important to note that the bulk optimizer is primarily for images outside the media library. Media library images are typically optimized on upload. The bulk tool scans your theme folders, some plugin paths, and any custom folders you specify. If it's not finding images, you may need to configure the Folders to Optimize setting in the plugin's advanced options.

5. Review the Debug Log

For deeper issues, enable debugging. Go to the plugin's support tab and enable the debug log. Reproduce the bulk optimization error, then check the log for detailed error messages. This can provide crucial clues, such as permission errors or specific file path failures.

6. Verify Database Integrity

If you reinstalled the plugin and the bulk optimizer shows errors about null properties or doesn't see any images, the necessary database tables may be missing. A complete uninstall and reinstall of the plugin should recreate these tables and resolve the issue.

Conclusion

Bulk optimization failures in EWWW Image Optimizer are usually solvable by methodically checking server settings, reviewing potential conflicts, and ensuring the plugin is configured correctly for your specific site setup. Starting with the most common solutions—managing server timeouts, disabling parallel optimization, and checking for conflicts—will resolve the majority of issues users encounter.

Related Support Threads Support