February 21, 2026 By Semih Çatal 7 min read

Why WebP Is Not Supported on Some Browsers: Causes & Fixes (2026)

WebP is widely supported across modern web browsers in 2026, offering massive performance benefits and smaller file sizes compared to traditional formats like JPG and PNG. However, web developers, WordPress site owners, and everyday users still frequently report frustrating issues where WebP images fail to load, display as blank thumbnails, or trigger confusing compatibility warnings.

If you've encountered broken images on your website or received complaints from users who cannot view your visual content, you are not alone. In this comprehensive guide, we will explore exactly why WebP may not be supported in certain environments, the technical reasons behind these failures, and how to fix them permanently.

Is WebP Supported by All Browsers?

The short answer is: Almost, but not entirely. As of 2026, global browser support for WebP sits comfortably above the 95% mark. Most modern, updated browsers handle the format natively and seamlessly, including:

However, that remaining ~5% represents millions of users globally. Older browser versions, legacy operating systems, specific embedded applications, and e-mail clients may lack the necessary codecs to decode and render the WebP format. When these unsupported environments encounter a `.webp` file without a fallback, the image simply breaks.

Common Reasons WebP Does Not Work (And How to Fix Them)

Compatibility issues usually stem from a handful of specific configuration errors or environmental limitations. Let's break down the most common culprits and their technical solutions.

1. Outdated Browser Versions & OS Limitations

While Chrome and Firefox adopted WebP years ago, Apple's Safari was notably late to the party. Safari only introduced WebP support in macOS 11 Big Sur and iOS 14. If a user is visiting your website on an older MacBook running macOS Catalina (10.15) or an iPhone stuck on iOS 13, their Safari browser physically cannot read the WebP format.

Similarly, Internet Explorer (which is officially retired but still lingering in some enterprise environments) has zero support for WebP.

The Solution: You cannot force a user to update their operating system. Instead, you must implement structural fallbacks in your HTML (explained in section 3) to ensure these users are served a standard JPG image instead.

2. Incorrect Server Configuration (Missing MIME Types)

This is arguably the most common issue faced by developers moving to WebP. When a browser requests an image from your server, the server responds not just with the image data, but with an HTTP header specifying the MIME type. This tells the browser exactly how to process the incoming byte stream.

If your web server is not explicitly configured to recognize `.webp` files, it may serve the image with a generic MIME type like application/octet-stream or text/plain. When the browser receives this, it refuses to render it as an image, resulting in a broken icon.

The Fix for Apache Servers: You need to add the correct MIME type to your `.htaccess` file.

# Add WebP MIME type in Apache
<IfModule mod_mime.c>
    AddType image/webp .webp
</IfModule>

The Fix for Nginx Servers: Add the MIME type to your `mime.types` configuration file.

# Add WebP MIME type in Nginx
types {
    image/webp webp;
}

3. Missing Fallback Images (The HTML Picture Element)

If your website's HTML directly references a WebP file like this: <img src="photo.webp">, you are creating a single point of failure. If the browser does not support WebP, the image breaks entirely.

The Best Practice Fix: Modern web development dictates the use of the HTML5 <picture> element. This allows you to serve the WebP image to browsers that support it, while seamlessly "falling back" to a JPG for browsers that do not.

<picture>
  <!-- Browser will try to load this first if it supports WebP -->
  <source srcset="image.webp" type="image/webp">
  
  <!-- Fallback for older browsers (Safari 13, IE11) -->
  <img src="image.jpg" alt="A description of the fallback image">
</picture>

This method guarantees 100% compatibility across all browsers, old and new.

4. CDN or Caching Misconfigurations (The Accept Header)

Many modern Content Delivery Networks (CDNs) like Cloudflare or Akamai offer "Auto-WebP" features. They detect if a visitor's browser supports WebP (by reading the Accept: image/webp HTTP header) and dynamically convert your JPG to WebP on the fly.

However, if your server's caching layer (like Varnish, Redis, or a WordPress caching plugin) is misconfigured, it might cache the WebP version and accidentally serve it to a user whose browser does not send the WebP Accept header.

The Solution: Ensure your caching infrastructure is configured to Vary by the Accept header. Your server must cache separate versions of the page/image based on whether the incoming request supports WebP.

# Apache Vary Header Example
<IfModule mod_headers.c>
    Header append Vary Accept env=REDIRECT_accept
</IfModule>

5. Email Client Limitations

Web browsers and email clients use fundamentally different HTML rendering engines. While browsers update constantly, email clients are notoriously stagnant. Microsoft Outlook, for example, uses a Word-based rendering engine that simply does not support modern web standards like WebP, AVIF, or even basic CSS grid.

If you embed a WebP image into a newsletter campaign, a massive percentage of your subscribers will see a broken box.

The Fix: Never use WebP in email marketing. Always stick to highly compressed JPG or PNG files for maximum inbox compatibility.

How to Check Browser Support Dynamically

If you are building a custom web application, you might want to detect WebP support dynamically via JavaScript before requesting high-resolution assets.

You can use the following lightweight JavaScript function. It attempts to load a tiny, 2-pixel Base64 encoded WebP image. If it loads successfully, the browser supports WebP.

function supportsWebP() {
  return new Promise((resolve) => {
    const webP = new Image();
    webP.onload = webP.onerror = function () {
      resolve(webP.height === 2);
    };
    webP.src = "data:image/webp;base64,UklGRiIAAABXRUJQVlA4TBEAAAAvAAAAAAfQ//73v/+BiOh/AAA=";
  });
}

// Usage Example:
supportsWebP().then(hasSupport => {
  if(hasSupport) {
    console.log("WebP is supported! Load modern assets.");
  } else {
    console.log("WebP not supported. Load JPG fallbacks.");
  }
});

When Should You Avoid WebP Entirely?

Despite its incredible performance benefits for general web delivery, you should intentionally avoid WebP (and stick to JPG) in the following scenarios:

Troubleshooting Compatibility: Quick Reference Table

Use this quick reference table to diagnose and fix your specific WebP issues instantly:

The Issue The Root Cause The Fix
Image shows as broken icon on all browsers Missing or incorrect MIME type on server. Add image/webp to Apache/Nginx config.
Broken only on older iPhones/Macs User is on Safari 13 or older (iOS 13 / Catalina). Use the HTML <picture> element with a JPG fallback.
Images broken randomly for different users Aggressive caching ignoring Accept headers. Configure CDN/Cache to Vary: Accept.
Broken in Email Newsletters (Outlook, etc.) Email rendering engines do not support WebP. Strictly use JPG or PNG for all email campaigns.
Downloaded WebP file won't open on PC OS lacks native WebP codec/viewer. Convert the file back to JPG locally.

WebP vs JPG for Maximum Compatibility

While WebP drastically improves page load performance, JPG remains the undisputed king of universal compatibility. A well-architected website will use WebP for delivery to modern browsers while maintaining JPGs as the sturdy, reliable fallback.

If you find yourself stuck with WebP files that you or your clients cannot open, edit, or upload to specific platforms, you need a fast and private way to revert them to a standard format.

Need universal compatibility right now? Convert your WebP images back to JPG securely.

Use the Free Client-Side Converter

Final Thoughts

WebP is an incredibly powerful format that is broadly supported across the modern web. In 2026, most compatibility problems are not caused by the format itself, but rather by server configuration errors, aggressive caching, outdated devices, or missing HTML fallbacks.

By implementing correct MIME types, utilizing the <picture> element, and knowing exactly when to fall back to JPG, you can harness the performance benefits of WebP without alienating a single user.

Frequently Asked Questions

Why are my WebP images showing as broken links?

Broken WebP images are usually caused by a missing MIME type configuration on your server. If your Apache or Nginx server does not explicitly send the "image/webp" HTTP header, the browser won't know how to render the file, resulting in a broken image icon.

Does Apple Safari support WebP?

Yes, but only on modern versions. Safari introduced WebP support in macOS 11 Big Sur and iOS 14. Users on older Apple operating systems (like macOS Catalina or iOS 13) cannot view WebP images natively and require a JPG fallback.

Why don't WebP images load in my email newsletter?

Email clients use entirely different, often outdated HTML rendering engines compared to web browsers. For instance, Microsoft Outlook uses a Word-based rendering engine that does not support WebP. You should always use JPG or PNG for email marketing.

How do I provide a fallback for unsupported browsers?

The best practice for providing a fallback is using the HTML <picture> element. You define the <source> as the WebP file, and use a standard <img> tag with a JPG as the fallback for older browsers.