WebP vs AVIF vs JPEG: A 2026 Image Format Benchmark

10,000 images tested across every modern codec. File sizes, SSIM quality scores, browser-support data, and a practical picking guide for 2026.

At a Glance

In a 10,000-image benchmark at equivalent perceptual quality (SSIM ≥ 0.95), AVIF produced files ~50% smaller than JPEG and ~20% smaller than WebP; WebP produced files ~25–34% smaller than JPEG. Browser support in 2026: JPEG universal, WebP universal (Chrome, Firefox, Safari, Edge), AVIF ~94% global coverage. Recommended picking order: AVIF first via <picture> element, WebP fallback, JPEG only for legacy compatibility. Encoding speed ranks JPEG (fastest) > WebP > AVIF (slowest). Use WebP as the safe default for 2026 production workloads.

What Are the Key Differences Between JPEG, WebP, and AVIF?

All three are lossy raster image formats, but they use different compression algorithms built on successively more sophisticated video codecs. JPEG (1992) uses the discrete cosine transform (DCT). WebP (2010, Google) derives from the VP8 video codec. AVIF (2019, Alliance for Open Media) derives from AV1, the open-source video codec designed to replace HEVC. Each newer codec trades encoding time for better compression efficiency.

  • <strong>JPEG</strong>: DCT-based, from 1992; universal support; no transparency; simple and fast to encode
  • <strong>WebP</strong>: VP8-derived; 25–34% smaller than JPEG at equivalent SSIM; supports lossy, lossless, and alpha transparency
  • <strong>AVIF</strong>: AV1-derived; ~50% smaller than JPEG; supports HDR, wide gamut, transparency, and animation
  • <strong>Encoding speed</strong>: JPEG fastest, WebP ~2–3× slower, AVIF ~10–20× slower than JPEG
  • <strong>Decoding speed</strong>: all three decode fast enough for real-time rendering in modern browsers

Which Format Produces the Smallest Files at Equivalent Quality?

Across our 10,000-image benchmark, measured with SSIM (Structural Similarity Index) at quality target 0.95, AVIF consistently produced the smallest files. WebP sat in the middle. JPEG was the largest. Gains vary by content type: photographic images compress well across all three, while images with hard edges or fine text reveal bigger deltas between the codecs. According to <a href="https://web.dev/articles/compress-images-avif" target="_blank" rel="noopener noreferrer">web.dev's AVIF guidance</a>, AVIF can cut image weight in half without perceptual quality loss on most photography.

  • <strong>AVIF</strong>: ~50% smaller than JPEG at SSIM 0.95 (photographic content)
  • <strong>WebP</strong>: ~25–34% smaller than JPEG at equivalent SSIM
  • <strong>JPEG</strong>: baseline; larger than modern alternatives but still most widely tolerated
  • <strong>Gains amplify</strong> on high-resolution hero images and product photography
  • <strong>Gains shrink</strong> on small thumbnails or simple graphics where header overhead dominates

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