The State of Image Formats in 2026
For years, the choice was simple: JPEG for photos, PNG for graphics. Today, WebP and AVIF have matured enough to challenge JPEG as the default web image format. But which one should you actually use? The answer depends on your priorities: maximum compression, encoding speed, browser coverage, or feature support.
This guide compares all three formats across the metrics that matter.
Technical Overview
JPEG (1992)
JPEG uses a Discrete Cosine Transform (DCT) to separate image data into frequency components, then quantizes and entropy-codes the result. It's fast to encode and decode, but it doesn't support transparency or animation, and its compression efficiency hasn't improved significantly since the format was standardized.
WebP (2010)
Google's WebP uses block prediction and transform coding derived from the VP8 video codec (lossy mode) and a separate lossless algorithm with advanced entropy coding. It supports transparency (alpha channel), animation, and both lossy and lossless compression.
AVIF (2019)
AVIF is based on the AV1 video codec, developed by the Alliance for Open Media (Google, Apple, Mozilla, Netflix, and others). It supports HDR, wide color gamut (10- and 12-bit), transparency, and animation. Its compression efficiency is the best of the three, but encoding is computationally expensive.
Head-to-Head Comparison
| Feature | JPEG | WebP | AVIF |
|---|---|---|---|
| Compression type | Lossy only | Lossy + Lossless | Lossy + Lossless |
| Typical savings vs JPEG | — | 25–35% | 40–55% |
| Transparency (alpha) | No | Yes | Yes |
| Animation | No | Yes | Yes |
| HDR / Wide color gamut | No (8-bit) | No (8-bit) | Yes (10/12-bit) |
| Max resolution | 65,535 × 65,535 | 16,383 × 16,383 | 65,536 × 65,536 (tiled) |
| Encoding speed | Very fast | Fast | Slow (3–10× slower) |
| Decoding speed | Very fast | Fast | Moderate |
| Progressive loading | Yes | No | No (but tiled decoding) |
| Browser support (2026) | 100% | 97%+ | 92%+ |
| Spec license | Free (patent-encumbered legacy) | BSD (Google) | Royalty-free (AOM) |
Compression Efficiency in Practice
To put real numbers behind the comparison, we compressed a set of 20 diverse photographs at equivalent visual quality (SSIM ≈ 0.95) using Deflato:
- JPEG at quality 80: average file size 247 KB
- WebP at quality 80: average file size 158 KB (36% smaller)
- AVIF at quality 65: average file size 112 KB (55% smaller)
The AVIF savings are striking, especially for photographic content with smooth gradients and fine textures. For images with sharp edges and flat colors (like screenshots or illustrations), WebP lossless often competes closely with AVIF.
Browser Support in Detail
As of March 2026:
- WebP: Supported in Chrome 23+, Firefox 65+, Safari 14+, Edge 18+, and all major mobile browsers. The only notable holdout is very old iOS devices stuck on iOS 13 or earlier.
- AVIF: Supported in Chrome 85+, Firefox 93+, Safari 16.4+, Edge 121+, Samsung Internet 16+. Older Samsung Internet and some niche browsers may still lack support.
For most sites targeting a global audience in 2026, WebP is safe to use without a fallback. AVIF is safe for the vast majority of users, but a WebP or JPEG fallback is recommended if you need to cover the long tail.
When to Use Each Format
Use JPEG when…
- You need universal compatibility with legacy systems, email clients, or native apps that don't support modern formats
- Encoding speed is critical (e.g., real-time thumbnail generation)
- You're working with tools or CMSes that don't support WebP/AVIF output
Use WebP when…
- You want a safe, well-supported upgrade from JPEG with good savings
- You need transparency without the file size penalty of PNG
- Encoding speed matters (WebP encodes 3–5× faster than AVIF)
- You want a single format that works in nearly all browsers without fallbacks
Use AVIF when…
- Maximum compression is the priority (bandwidth-constrained users, large image galleries)
- You need HDR or wide color gamut support
- You can provide a WebP or JPEG fallback for older browsers
- Encoding time is not a bottleneck (static site builds, batch processing)
Converting Between Formats with Deflato
Deflato supports all three formats as both input and output. You can convert a batch of JPEGs to WebP or AVIF in seconds:
- Upload your images (drag and drop, or paste a URL)
- Select the output format from the dropdown (JPEG, WebP, or AVIF)
- Adjust the quality slider — the file size estimate updates live
- Download the results individually or as a ZIP
If you need to automate conversions, the Deflato API accepts an output_format parameter:
curl -X POST https://deflato.com/api/v1/compress -H "Authorization: Bearer YOUR_API_KEY" -F "file=@photo.jpg" -F "output_format=AVIF" -F "quality=65" --output photo.avifConclusion
There is no single "best" format — only the best format for your situation. For most websites in 2026, WebP is the practical default: excellent compression, universal support, fast encoding. If you want to squeeze out every last byte, AVIF is the winner on compression, provided you can handle the slower encoding and serve a fallback. JPEG remains relevant for legacy workflows and systems that haven't caught up to modern formats.
The easiest path: serve AVIF with a WebP fallback and a JPEG safety net. Tools like Deflato make generating all three variants painless.