WordPress AVIF Images — How to Serve AVIF Without a Paid Plugin

WordPress 6.5 (released April 2024) added native AVIF upload support to the Media Library — you can now upload AVIF files directly without any plugin. Combined with a free JPG-to-AVIF converter, you can cut your WordPress site's image weight by 50–70% without paying for Imagify, ShortPixel, or similar optimization plugins. Here is the complete workflow.

WordPress 6.5 Now Accepts AVIF Files in the Media Library

Before WordPress 6.5, you had to use a plugin (Imagify, ShortPixel, WebP Express) or Cloudflare to serve AVIF images. As of WordPress 6.5, the core software accepts AVIF uploads directly.

How to check your version: go to Dashboard > Updates. If you are on 6.5 or later, you can upload AVIF files straight to the Media Library and insert them into posts and pages like any other image.

If you are on an older WordPress version, you have two options:

• Update to WordPress 6.5+ — recommended. Core updates are free and the update process is straightforward.
• Use a plugin — free options like WebP Converter for Media handle AVIF serving on older WordPress versions.

The Free Workflow: Convert JPG to AVIF, Then Upload

The manual approach gives you the most control:

1. Identify images to optimize — focus on large images in your theme (hero image, featured images) and frequently-visited posts. These give the biggest impact.
2. Convert JPG to AVIF — use the free converter: drop your JPGs, download the AVIF files. Set quality to 50–55 for photographs, 60+ for product images with fine detail.
3. Upload AVIF to WordPress — go to Media > Add New, and upload your AVIF files. WordPress 6.5+ treats them like any other image.
4. Replace images in posts and pages — in the Block Editor, click on an image block, click Replace, and choose your new AVIF file from the media library.
5. Add a fallback for older browsers — if you have visitors on older Safari (pre-iOS 16), add a fallback using the HTML block with a picture element.

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Automatic AVIF Delivery with Cloudflare (Free)

If your WordPress site is behind Cloudflare (the free CDN), you can enable automatic image format negotiation — Cloudflare serves AVIF to supported browsers and your original JPG to others, without you touching individual images.

To enable it:

1. Go to your Cloudflare dashboard and select your site.
2. Navigate to Speed > Optimization > Content Optimization.
3. Enable Polish (requires Cloudflare Pro plan, $20/month) — this handles AVIF/WebP conversion automatically.

Free Cloudflare plan alternative: manually convert and upload AVIF files as described above. Cloudflare's CDN will still cache and serve them efficiently — you just handle the conversion step yourself.

Real Impact on WordPress Page Speed

Image optimization is one of the highest-impact changes you can make to a WordPress site's speed. Typical results after converting to AVIF:

• Page weight reduction: 40–60% smaller pages on image-heavy posts
• LCP improvement: hero images that took 2.5s to load often drop to 1.2–1.5s
• PageSpeed Insights score: sites that previously scored 60–70 on mobile often jump to 80–90 after image optimization

Run your site through Google PageSpeed Insights before and after — it will flag any remaining oversized images and show exactly how much time each image adds to your load time. Images are almost always the biggest opportunity on content-heavy WordPress sites.

Frequently Asked Questions

Does WordPress automatically convert my uploaded JPGs to AVIF?

Not by default in the free version. WordPress 6.5 accepts AVIF uploads but does not automatically convert existing JPGs. To get AVIF output, you need to either manually convert before uploading (using the free converter) or use a plugin like Imagify or ShortPixel that handles automatic conversion on upload.

Will AVIF images break my site on older browsers?

Only if you use AVIF without a fallback. If you upload AVIF to your media library and use it as the only source for an image block, visitors on very old browsers (IE, Safari pre-2022) will see a broken image. Use the HTML picture element with a JPG fallback, or serve both with a plugin that handles format negotiation automatically.

Which WordPress plugins convert images to AVIF automatically?

Imagify, ShortPixel, and Smush Pro all support AVIF conversion on upload. The free tier of each plugin has monthly limits. For unlimited conversions, the manual pre-conversion workflow (convert JPG to AVIF before upload) is completely free and just requires an extra step.

How much does switching to AVIF improve WordPress Core Web Vitals?

The impact depends on your current images. Sites with unoptimized JPG hero images (1 MB+) typically see LCP improvements of 0.5–1.5 seconds. That translates directly to a better Google PageSpeed score and improved search ranking for page experience.