JPG to AVIF Converter

What is JPG to AVIF Conversion?

JPG to AVIF conversion is the process of transforming an image from the classic 1990s format into a modern next-generation format designed for maximum compression efficiency. AVIF (AV1 Image File Format) is based on the AV1 video codec and provides a 30-50% file size reduction compared to JPG while maintaining or even improving visual quality.

The AVIF format was standardized by the Alliance for Open Media (AOM) in 2019. The alliance includes the largest technology companies: Google, Apple, Microsoft, Amazon, Netflix, Meta, Mozilla, and Intel. Such support guarantees long-term format development and its widespread implementation in browsers, operating systems, and software.

AVIF is not just "another image format." It is the result of years of research in video compression, adapted for static images. The AV1 codec was originally created for 4K and 8K video streaming, which explains its exceptional efficiency when working with photographs.

History of AVIF and the AV1 Codec

From Video to Images

AV1 (AOMedia Video 1) has been developed since 2015 as an open and free alternative to proprietary video codecs like H.265/HEVC. The goal was to create a next-generation codec without licensing fees.

Key milestones:

• 2015 - founding of the Alliance for Open Media
• 2018 - finalization of the AV1 specification
• 2019 - publication of the AVIF specification for images
• 2020 - Chrome becomes the first browser with AVIF support
• 2021 - Firefox adds AVIF support
• 2023 - Safari receives full AVIF support

Why AV1 is So Efficient

AV1 includes over 100 innovative compression technologies:

• Block prediction - more flexible than in JPEG or WebP
• Superblocks - adaptive image partitioning into blocks from 4x4 to 128x128 pixels
• Warped motion - compensation for complex distortions
• Film grain synthesis - preserving film grain with minimal impact on size

These technologies were developed for video but work excellently for photographs as well.

Technical Differences Between JPG and AVIF

Comparison of Compression Algorithms

JPG (JPEG) uses Discrete Cosine Transform (DCT), developed in 1992:

• Fixed 8x8 pixel blocks
• Single prediction mode
• Lossy compression only, no lossless option
• No alpha channel support

AVIF uses modern AV1 codec technologies:

• Adaptive blocks from 4x4 to 128x128 pixels
• More than 60 intra-prediction modes
• Support for lossy, lossless, and their combination
• Full alpha channel support

Detailed Feature Comparison

Real Examples of Size Reduction

Conversion results for typical photographs:

Moreover, the visual quality of AVIF q60 is comparable to JPG q85 - compression artifacts are less noticeable due to advanced algorithms.

Advantages of the AVIF Format

Superior Compression

AVIF provides a 30-50% file size reduction compared to JPG at similar visual quality. For large websites, this means:

• Savings of terabytes of traffic monthly
• Reduced load on servers and CDNs
• Lower costs for hosting and data transfer

HDR and Wide Color Gamut Support

AVIF is the first widely supported web format with HDR:

• 10-bit and 12-bit color depth - 4096 or 16384 brightness levels instead of 256 in JPG
• Wide color gamut (BT.2020) - more shades, especially greens and reds
• PQ and HLG - HDR standards for modern displays

For owners of HDR monitors and modern smartphones, photographs in AVIF look significantly more vibrant and realistic.

Transparency and Layers

Unlike JPG, AVIF supports an alpha channel for transparency:

• Semi-transparent effects and shadows
• Images with cutout backgrounds
• Overlay graphics on any background

At the same time, the file size remains smaller than PNG with similar transparency.

Fewer Compression Artifacts

AV1 algorithms create less noticeable artifacts:

• No blockiness (no visible 8x8 block boundaries)
• Better gradient preservation (less banding)
• More accurate preservation of fine details and textures
• More natural edge processing of objects

When JPG to AVIF Conversion is Necessary

Website Optimization

AVIF is particularly effective for:

Hero images - main banners take up a significant portion of page load. Reducing their size by 50% noticeably improves load time and LCP.

E-commerce stores - thousands of product cards with photos. Saving 50% on each image is critical for total data volume.

Galleries and portfolios - large numbers of high-resolution images require maximum optimization.

News portals - articles with numerous illustrations load faster, improving behavioral factors.

Impact on Core Web Vitals

Google uses Core Web Vitals as a ranking factor. AVIF directly affects metrics:

LCP (Largest Contentful Paint) - time to render the main content. If the largest element is an image, reducing its size by 50% proportionally speeds up LCP.

FID/INP - interactivity delay. Less data to load means the main thread is freed up faster.

Switching to AVIF can improve PageSpeed Insights scores by 10-20 points for image-heavy websites.

Conversion Process: How Encoding Works

Stages of JPG to AVIF Conversion

1. JPG decoding - the source file is unpacked, pixels are restored with pre-existing compression artifacts.

2. Image analysis - the encoder determines optimal block partitioning, prediction modes for each region.

3. Intra-frame prediction - for each block, the best of 60+ prediction modes is selected based on neighboring pixels.

4. Transform and quantization - the difference between prediction and actual data is transformed and quantized with the specified quality level.

5. Entropy coding - the result is compressed using CABAC method to minimize file size.

6. AVIF formation - data is packaged into a HEIF container (ISO Base Media File Format) with metadata.

Encoding Speed

AVIF encodes slower than WebP and JPG due to the complexity of AV1 algorithms. Typical encoding time ratios:

For one-time conversion, this is not critical, but when processing thousands of images, AVIF requires significant computational resources.

AVIF Browser Compatibility

Current Support (2024)

Not supported: Internet Explorer, Safari before version 16.4, old versions of all browsers.

Global Coverage

According to Can I Use data, AVIF is supported by approximately 85-90% of browsers globally. For some regions, this percentage may be lower due to slower browser updates.

Software Support

AVIF vs WebP: What to Choose

Direct Comparison

Recommendations for Choosing

Use AVIF if:

• Maximum compression is critical for your project
• Your audience uses modern browsers
• You need HDR or wide color gamut support
• You are ready to implement fallback to WebP/JPG

Use WebP if:

• Maximum compatibility is important
• You need fast on-the-fly image generation
• Your audience includes users of older browsers

Optimal strategy: AVIF -> WebP -> JPG (progressive enhancement)

Implementing AVIF on Websites

HTML picture Tag with Fallback

<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description" width="800" height="600">
</picture>

The browser will choose the first supported format. Older browsers will receive JPG.

Server-Side Delivery via Accept Header

Nginx or CDN can automatically serve AVIF to browsers with support:

Accept: image/avif,image/webp,image/*

Cloudflare, Fastly, and other CDNs offer automatic conversion and delivery of the optimal format.

Quality Settings Optimization

Recommended quality values for balancing size and visual quality:

• Quality 60-70 - optimal for web, ~50% savings from JPG
• Quality 80-85 - high quality, ~30-40% savings
• Quality 90+ - minimal losses, but less size benefit

AVIF Format Limitations

Encoding Speed

AVIF encodes 10-50 times slower than JPG. This is critical for:

• Services with on-the-fly image conversion
• Processing user uploads in real-time
• Generating thumbnails on demand

Solution: pre-convert in offline mode, cache results.

Limited Support

About 10-15% of browsers do not support AVIF:

• Old versions of Safari (before 16.4)
• Internet Explorer (no longer relevant)
• Outdated mobile browsers

Solution: mandatory fallback to WebP or JPG.

Maximum Image Size

The AVIF specification limits size to 65535x65535 pixels. In practice, this is not a problem, but worth considering for gigapixel images.

Software Support

Not all programs support AVIF:

• Older versions of Photoshop require a plugin
• Many Windows 10 viewers cannot open AVIF
• Some CMS require additional modules

The situation is rapidly improving with each software update.