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WebP vs AVIF vs JPEG: Which Image Format Should You Use in 2026?

The image format landscape has changed. JPEG is no longer the automatic default. Here's a practical comparison to help you pick the right format for every use case.

The short answer

• WebP if you want the best balance of quality, size, and compatibility
• AVIF if you want the smallest files and can tolerate slower encoding
• JPEG if you need maximum compatibility with legacy systems
• PNG only when you need lossless with transparency

File size comparison

Using a typical 12MP photo at perceptually equivalent quality:

AVIF consistently produces files 40-50% smaller than JPEG. WebP is 25-35% smaller. Both with no perceptible quality difference.

Browser support in 2026

As of 2026, all major browsers support both WebP and AVIF. Safari was the last holdout for both, but Safari 16.1 added AVIF support. For general web use, you can safely use either format.

Encoding speed

This is where the formats differ most in practice:

• JPEG: Very fast. Encoding a 12MP image takes ~100ms.
• WebP: Fast. About 2-3x slower than JPEG, still well under a second per image.
• AVIF: Slow. Can take 3-10 seconds per image depending on settings. This matters for batch processing.

If you're converting thousands of images, AVIF's encoding time adds up. ConvX's parallel processing (-j flag) helps by using multiple CPU cores, but WebP is still significantly faster for large batches.

When to use each format

Use WebP when:

• You need a drop-in JPEG replacement that's smaller
• You're processing large batches and encoding speed matters
• You want transparency support (WebP supports alpha, JPEG doesn't)
• You're not sure — WebP is the safe, universally good choice

Use AVIF when:

• File size is the top priority (bandwidth-constrained, mobile-heavy audience)
• You're serving static assets and can pre-encode (CDN, build pipeline)
• You're doing photography or images with fine gradients (AVIF handles these well)

Use JPEG when:

• You need compatibility with legacy systems, email clients, or older apps
• You're sending files to people who may be on older software
• You're interfacing with systems that don't accept newer formats

Converting between formats with ConvX

# JPEG to WebP
convx convert photo.jpg --to webp -q 80

# JPEG to AVIF
convx convert photo.jpg --to avif -q 80

# Batch convert entire folder
convx convert "./images/*.jpg" --to webp -j 4 -d ./optimized

# Use the web-image preset (WebP, quality 80, metadata stripped)
convx convert photo.jpg --preset web-image

Can I use both WebP and AVIF?

Yes. The <picture> element lets you serve AVIF to browsers that support it, WebP as a fallback, and JPEG as a last resort:

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

This gives every visitor the smallest possible file while maintaining universal compatibility.