Troubleshooting WebP Images Not Displaying on iPhone and Safari

Many users of the 'Imagify Image Optimization – Optimize Images | Compress Images | Convert WebP | Convert AVIF' plugin report a common issue: WebP images fail to display correctly on Apple devices, particularly iPhones and in the Safari browser. Instead of showing the image or falling back to the original JPEG/PNG format, users often see a blank space, an empty box, or a broken image icon. This guide will explain why this happens and walk you through the most effective troubleshooting steps.

Why Does This Happen?

The core of this issue typically lies in how WebP support is handled by different browsers and potential conflicts with other website scripts. Based on community reports, the main causes are:

• Browser Support Gaps: While Safari now supports WebP, this support was rolled out gradually. Full support for the desktop version of Safari arrived later than for iOS. Older threads indicate that some versions of Safari may still have issues with certain WebP implementations.
• Lazy Load Conflicts: A recurring theme in support threads is a conflict between WebP delivery and lazy loading plugins (e.g., from WP Rocket). The combination can sometimes break the fallback mechanism on less common browsers.
• Display Method: The plugin offers two primary methods to serve WebP images: using <picture> tags or Apache rewrite rules. Each method has its own strengths and potential pitfalls depending on your server configuration and other active plugins.
• Third-Party Plugin/Theme Conflicts: Some page builders, sliders (like LayerSlider), and themes may not fully support the HTML structure or server rules used to deliver WebP files, preventing proper display.

How to Troubleshoot and Fix the Issue

Follow these steps to identify and resolve the problem. Always clear your cache (both on your site and your browser) after each change.

1. Verify the Current Status

First, ensure WebP display is actually enabled in your Imagify settings. Sometimes, the feature may have been turned off during troubleshooting. Also, check if the issue is present on your live front-end page, not just in a customizer or preview mode.

2. Switch the WebP Delivery Method

This is the most common and effective fix. Imagify provides two ways to serve WebP images:

• Use <picture> tags (preferred): This method wraps the WebP image in HTML5 <picture> tags with a fallback to the original image. It is generally the most compatible method.
• Use rewrite rules: This method uses Apache server rules to dynamically serve the WebP file to supporting browsers. This requires that your server runs on Apache (not NGINX) and that the mod_rewrite module is active. Note: This method is not compatible with most CDNs.

If you are using one method and experiencing issues, try switching to the other. The 'Imagify Image Optimization – Optimize Images | Compress Images | Convert WebP | Convert AVIF' team suggests that if you are not using a CDN, the rewrite rules method can often resolve display issues.

3. Check for Conflicts with Lazy Loading

Temporarily disable any lazy loading features, either from a plugin like WP Rocket or your theme. Then, check your site on an iPhone again. If the images load correctly, you have identified a conflict. You may need to reconfigure your lazy load settings or exclude certain images from being lazy-loaded.

4. Isolate Third-Party Plugin and Theme Conflicts

Conflicts with other plugins or your theme are a common cause. To test this:

1. Temporarily switch your theme to a default WordPress theme like Twenty Twenty-Four.
2. Deactivate all other plugins except Imagify.

If the WebP images display correctly on iPhone after this, reactivate your plugins one by one and switch back to your theme, testing after each change, to find the culprit. As seen in the threads, plugins like LayerSlider have historically had compatibility issues that may require an update from their development team.

5. Test with Another WebP Plugin

For advanced troubleshooting, you can test if the issue is specific to Imagify's implementation. Install another WebP plugin (e.g., WebP Express) and configure it. If the problem persists with a different plugin, the issue is likely related to your server configuration or a broader conflict with your theme/other plugins. If it works, the issue may be specific to Imagify's current interaction with your site setup.

By methodically working through these steps, you can identify the root cause of why WebP images are not displaying on iPhones or in Safari and apply the appropriate fix.