AVIF Format Deep Dive: Next-Gen Image Compression Explained

Every few years, a new image format arrives promising smaller files and better quality. Most fade into obscurity. AVIF is different. Backed by the Alliance for Open Media (AOM) — a consortium that includes Google, Apple, Mozilla, Microsoft, Netflix, and Amazon — AVIF is built on the AV1 video codec, one of the most efficient compression technologies ever developed. It is not a speculative experiment. It is the format that Netflix uses to serve billions of thumbnails, that Android uses as its default screenshot format, and that every major browser now supports.

AVIF consistently delivers 30–50% smaller files than JPEG and 20–30% smaller files than WebP at equivalent visual quality. It supports HDR, wide color gamuts, transparency, and animation. On paper, it is the best image format available today.

But AVIF also has real limitations. Encoding is significantly slower than JPEG or WebP. Browser support, while growing fast, has not yet reached the near-universal 97% that WebP enjoys. And the format's complexity means some tools and platforms still do not handle it well.

This guide covers everything you need to know about AVIF — how it works under the hood, how it compares to WebP and JPEG with real compression data, where browser support stands today, and how to adopt it progressively without breaking anything for your users.

How AVIF Works: AV1 Intra-Frame Coding for Images

AVIF stands for AV1 Image File Format. It takes the intra-frame coding technology from the AV1 video codec and packages it in the HEIF (High Efficiency Image File Format) container, as defined in the AOM AVIF specification. Understanding the underlying technology explains why AVIF compresses so much better than older formats.

AV1 Intra-Frame Coding

In video compression, an intra-frame (I-frame) is compressed independently without referencing other frames. AVIF uses AV1's intra-frame coding pipeline, which includes several techniques that go well beyond JPEG or WebP:

Flexible block partitioning. JPEG uses fixed 8×8 blocks and WebP uses 4×4 and 16×16 blocks. AV1 supports superblocks up to 128×128 pixels that can be recursively partitioned into varying sizes — large blocks for smooth areas, small blocks for detailed regions, allocating bits where they matter most.

Advanced prediction modes. AV1 offers over 50 directional intra-prediction modes compared to JPEG's none and WebP's 13. More accurate prediction means less data to store, resulting in dramatically better compression for gradients, patterns, and geometric shapes.

Multi-symbol arithmetic coding. AV1's entropy coder adapts to the statistical properties of image data, squeezing out savings that simpler coders like JPEG's Huffman coding leave on the table.

In-loop filtering. AV1 applies deblocking filters, constrained directional enhancement filters (CDEF), and loop restoration filters during decoding. These reduce blocking artifacts at block boundaries, allowing more aggressive quantization (smaller files) while maintaining visual quality.

HDR, Wide Color Gamut, and More

AVIF's feature set goes well beyond compression efficiency:

• Color depth: 8-bit, 10-bit, and 12-bit per channel (JPEG and WebP are limited to 8-bit). Higher bit depth eliminates banding in subtle gradients — sunset skies, skin tones, studio backdrops.
• Wide color gamuts: BT.2020 and BT.2100 support lets AVIF represent vivid colors outside the sRGB gamut that JPEG and WebP cannot encode.
• HDR transfer functions: PQ and HLG support enables true HDR images for HDR displays — increasingly valuable as HDR monitors become mainstream.
• Alpha transparency: Supported in both lossy and lossless modes, with independent compression for the alpha channel.
• Animation: Image sequences in the HEIF container offer a high-quality alternative to GIF and animated WebP, though tooling is still maturing.

AVIF vs WebP vs JPEG: Compression Comparison

The real test of any image format is how it performs on actual images. We compressed five test images across JPEG, WebP, and AVIF at equivalent visual quality to measure the differences.

Test Methodology

• Source images: Five images representing common web content — a landscape photograph, a portrait, a product shot on white background, a screenshot with text, and a graphic illustration with flat colors.
• Quality calibration: Rather than using the same numerical quality setting (which means different things in each format), we calibrated settings to produce equivalent SSIM (Structural Similarity Index) scores of approximately 0.95, representing high visual quality suitable for web delivery.
• JPEG settings: Quality 82, progressive encoding, 4:2:0 chroma subsampling.
• WebP settings: Quality 80, lossy mode.
• AVIF settings: Quality 65 (AVIF quality scales differently — lower numbers produce higher quality relative to JPEG/WebP), speed 4 (balanced encoding speed).
• Conversion tool: ImgCompress.app running client-side in Chrome 122 on a MacBook Pro (M2, 16 GB RAM).

Results

What the Data Shows

AVIF beats JPEG by 39–49% across all image types. The savings are most dramatic for photographic content, where AV1's advanced prediction modes and flexible block partitioning excel. Even the flat illustration sees a 39% reduction.

AVIF beats WebP by 19–33%. The gap is smaller than WebP-to-JPEG, but still substantial. For the landscape photo, AVIF saves an additional 117 KB over WebP — 32% smaller on top of WebP's already significant advantage.

Photographic content benefits most, but all types improve. Screenshots and illustrations show 19–21% savings over WebP — narrower margins because WebP already handles sharp edges and solid colors well, but AVIF still wins consistently.

Browser Compatibility: Where AVIF Stands in 2025

Browser support is the critical factor that determines whether you can actually use AVIF in production. Here is the current state based on Can I Use data as of early 2025.

Current Support

Global Support Percentage

According to Can I Use, AVIF has approximately 93% global browser support as of early 2025. This is a significant increase from 2023 when Safari's adoption brought Apple's entire ecosystem on board, but it still falls short of WebP's ~97% coverage.

The remaining ~7% comes primarily from:

• Older Safari versions on macOS Monterey and earlier (Safari 15 and below)
• Internet Explorer 11 (end of life, but still present in some enterprise environments)
• Older mobile browsers on devices that have not received OS updates
• Some niche and embedded browsers

What This Means in Practice

A 93% support rate is high enough for AVIF to be used as a primary format with fallbacks, but not high enough to serve AVIF exclusively without a fallback strategy. The practical approach is to serve AVIF to browsers that support it and fall back to WebP or JPEG for the rest — which is exactly what the <picture> element was designed for.

The good news is that AVIF support is only growing. Every major browser vendor has committed to the format, and as older browser versions age out of the install base, the support percentage will continue climbing toward WebP's 97% level.

Tutorial: Converting Images to AVIF with ImgCompress.app

Let us walk through converting images to AVIF format using ImgCompress.app, so you can see the process and evaluate the results for your own images.

Step-by-Step Conversion

1. Open our image converter in your browser. All conversion happens locally in your browser — your images are never uploaded to any server.

2. Drag and drop your source images (JPEG, PNG, or WebP) onto the upload area. You can upload multiple files for batch conversion.

3. Select AVIF as the target output format from the format dropdown.

4. Adjust the quality setting. For most web images, a quality setting of 60–70 provides an excellent balance of file size and visual quality. For hero images or product photography where quality is critical, use 75–85.

5. Click convert. AVIF encoding is more computationally intensive than JPEG or WebP, so expect slightly longer processing times — typically 2–5 seconds per image depending on dimensions and your device's processing power. ImgCompress.app uses Web Workers to keep the interface responsive during encoding.

6. Preview the results using the before-and-after comparison. Pay particular attention to:

   • Gradient areas (look for banding artifacts)
   • Fine text and sharp edges (check for blurring)
   • Areas with subtle texture (verify detail preservation)

7. Download the converted AVIF files individually or as a ZIP archive.

Recommended Quality Settings by Use Case

Conversion Tips

• Start with quality 65 and adjust from there. AVIF's quality scale works differently from JPEG — a lower number does not necessarily mean dramatically worse quality. Quality 65 in AVIF often looks comparable to JPEG quality 82.
• Compare at actual display size. AVIF artifacts are often invisible at the size the image will actually be displayed on your website. Zoom to 100% only if you need to verify quality for images that users might view at full resolution.
• Use lossless for graphics with text. If your image contains rendered text, diagrams, or pixel art, use lossless AVIF to avoid any compression artifacts around sharp edges.

For a broader overview of converting between all supported formats, see our Image Format Conversion Guide.

AVIF Advantages and Limitations

AVIF is an impressive format, but it is not perfect. Understanding both its strengths and weaknesses helps you make informed decisions about when and how to use it.

Advantages

Best-in-class compression efficiency. As our test data shows, AVIF consistently produces the smallest files at equivalent visual quality. For photographic content, the savings over JPEG (40–50%) and WebP (20–33%) are substantial enough to meaningfully impact page load times and bandwidth costs.

Superior handling of gradients and smooth tones. AVIF's 10-bit and 12-bit color depth support eliminates the banding artifacts that plague 8-bit JPEG and WebP in images with subtle gradients — sunset skies, studio backdrops, skin tones in portraits.

Future-proof HDR support. As HDR displays become standard on laptops, phones, and monitors, AVIF's native HDR capabilities will become increasingly valuable. No other widely-supported web image format offers comparable HDR support.

Royalty-free and open. AVIF is based on AV1, which was specifically designed to be royalty-free. Unlike HEIC (based on HEVC/H.265, which has complex patent licensing), AVIF can be used freely by anyone without licensing fees.

Strong industry backing. The Alliance for Open Media includes virtually every major tech company. This level of backing ensures continued development, optimization, and browser support for the foreseeable future.

Limitations

Slow encoding speed. AVIF's most significant practical limitation. Encoding takes 5–20× longer than JPEG — a few seconds instead of milliseconds per image. For batch processing hundreds of images, this adds up. AV1 encoder optimizations are ongoing and speed has improved substantially, but it remains slower than alternatives.

Incomplete browser support. At 93% global support, AVIF cannot be the sole format without leaving some users behind. A fallback strategy is required.

Limited tooling ecosystem. Major browsers and operating systems support AVIF, but many image editing tools, CMS platforms, and CDN services are still catching up. Some popular WordPress plugins and website builders do not yet handle AVIF natively.

Maximum dimension constraints. AV1 limits individual frames to 8192×4352 pixels in the baseline profile — sufficient for virtually all web images, but a constraint for very high-resolution photography.

Implementation complexity. Using AVIF requires the <picture> element for fallbacks, correct MIME type configuration (image/avif), and potentially updating your build pipeline to generate AVIF versions.

Progressive Adoption Strategy: AVIF + WebP + JPEG Fallback

Given AVIF's compression advantages and its current browser support limitations, the optimal approach for most websites in 2025 is a progressive adoption strategy that serves the best format each browser can handle.

The Three-Tier Fallback Pattern

The HTML <picture> element lets you specify multiple image sources in order of preference. The browser selects the first format it supports:

<picture>
  <source srcset="hero.avif" type="image/avif" />
  <source srcset="hero.webp" type="image/webp" />
  <img src="hero.jpg" alt="Description of the image" />
</picture>

With this pattern:

• 93% of browsers receive the AVIF version (smallest file)
• ~4% of browsers receive the WebP version (still much smaller than JPEG)
• ~3% of browsers receive the JPEG version (universal fallback)

The browser handles format selection automatically — no JavaScript, no server-side detection, no user-agent sniffing. It just works.

Implementation Considerations

Generate all three formats during your build process. Use your image optimization pipeline to create AVIF, WebP, and JPEG versions of each image. The storage cost of three versions is minimal compared to the bandwidth savings from serving the optimal format to each user.

Prioritize AVIF for your largest images. If generating three versions of every image feels excessive, start by creating AVIF versions of your hero images, product photos, and other large images where the compression savings have the most impact. Smaller images like icons and thumbnails can continue using WebP or PNG.

Configure your server's MIME types. Ensure your web server sends the correct Content-Type: image/avif header for .avif files. Most modern web servers and CDNs handle this automatically, but it is worth verifying.

Monitor your analytics. Track which format your visitors actually receive. As AVIF browser support grows, you may eventually be able to drop the JPEG fallback entirely, simplifying your pipeline to just AVIF + WebP.

When to Skip AVIF (For Now)

Consider sticking with WebP + JPEG if your images are primarily small icons or logos (where AVIF's advantage over WebP is modest), your build pipeline cannot accommodate a third format, encoding speed is a bottleneck for real-time processing, or your audience analytics show low AVIF-capable browser usage.

For most websites serving photographic content, the 30–50% savings over JPEG make AVIF worth the effort. Our Ultimate Image Compression Guide covers the broader strategy of choosing the right format for each image type.

The Future of AVIF

AVIF's trajectory is clear. Encoder performance continues improving — SVT-AV1 has made significant strides in reducing encoding time while maintaining efficiency. Adobe Photoshop, GIMP, and major CDN providers now offer AVIF support, and the tooling ecosystem is catching up quickly. With every major browser committed to the format, global support will naturally climb toward WebP's 97% level as older versions age out. Animated AVIF is also maturing, offering a high-quality alternative to GIF with dramatically better compression.

Conclusion

AVIF represents a genuine generational leap in image compression. Built on the AV1 codec with backing from every major tech company, it delivers 40–50% smaller files than JPEG and 20–33% smaller files than WebP at equivalent visual quality. Add native HDR support, wide color gamuts, 10/12-bit color depth, and a royalty-free license, and AVIF is the most capable image format available for the web today.

The practical reality in 2025 is that AVIF works best as part of a progressive strategy — serve AVIF to the 93% of browsers that support it, fall back to WebP for another 4%, and keep JPEG as the universal safety net. This three-tier approach using the <picture> element is simple to implement and ensures every visitor gets the smallest file their browser can handle.

The encoding speed trade-off is real but manageable. For pre-processed assets (blog images, product photos, marketing graphics), the extra encoding time is a one-time cost that pays for itself in reduced bandwidth on every page view. For real-time processing of user uploads, WebP remains the more practical choice until AVIF encoders get faster.

If you have not tried AVIF yet, the best way to evaluate it is with your own images. Convert a few of your largest photographs and compare the file sizes and visual quality against your current JPEG or WebP versions. The numbers will speak for themselves.

Ready to convert your images to AVIF? Try our free format converter — it runs entirely in your browser, supports AVIF along with JPEG, PNG, and WebP, and lets you compare results before downloading.

Related reading:

• Ultimate Image Compression Guide 2025: Reduce File Size by 90%
• WebP vs PNG: Complete Format Comparison Guide for 2025
• Image Format Conversion Guide: JPG, PNG, WebP & AVIF Explained