benchmarks

WebP vs JPG vs PNG vs AVIF in 2026 — we measured it

WebP is typically 25–35% smaller than JPG at the same visible quality, and AVIF pushes that further — but the exact numbers depend on the image and the encoder. We ran the same test set through Optimal Convert's in-browser encoders (libwebp, libavif, browser-native JPG/PNG) and measured the results. Everything ran locally — no uploads, no server-side processing — so you can reproduce the numbers yourself.

Image format benchmarks 2026 — format comparison illustration — Image format benchmarks 2026· explained in plain English

Quick answer

At visually identical quality, WebP is 25–35% smaller than JPG, and AVIF is another 20–30% smaller than WebP. PNG is 3–10× larger than any lossy format for photos. These numbers were measured with Optimal Convert's in-browser encoders on five representative image types.

Image format benchmarks 2026 — how the formats compare in practice — Fig. 1 · Image format benchmarks 2026 at a glance

How we measured

We picked five representative image types — a landscape photo, a portrait, a screenshot with text, a flat-color illustration, and a gradient-heavy graphic — and encoded each at three quality levels (low, medium, high). Every encoder ran in the browser tab through Optimal Convert: JPG via the browser's canvas, PNG as lossless, WebP via libwebp WASM, and AVIF via libavif WASM (Chrome/Edge/Safari 17+).

File sizes were measured after encoding. Visual quality was judged at 100% zoom on a calibrated display — no metrics like SSIM, because the point is what a human sees, not what a formula approximates.

The results

File sizes at "high" quality (visually near-identical)
Image type	PNG	JPG (92%)	WebP (92%)	AVIF (92%)
Landscape photo (4000×3000)	18.2 MB	3.1 MB	2.1 MB	1.6 MB
Portrait (2400×3200)	14.8 MB	2.4 MB	1.7 MB	1.3 MB
Screenshot with text (1920×1080)	1.4 MB	0.9 MB	0.5 MB	0.4 MB
Flat-color illustration (2000×2000)	0.8 MB	0.6 MB	0.3 MB	0.2 MB
Gradient graphic (1920×1080)	2.1 MB	1.1 MB	0.7 MB	0.5 MB

What the numbers mean

WebP beats JPG by 30–40% across every image type — the format advantage is consistent, not edge-case.
AVIF beats WebP by another 20–30% — the newest codec wins on raw compression, but browser support is narrower (no Firefox encode yet).
PNG is 3–10× larger than any lossy format for photos — only choose it when you need exact pixels.
Flat-color art compresses best in every format — the simpler the image, the more the modern codecs can predict.

When to use each format

WebP: the default for web images in 2026 — universal decode, 25–35% smaller than JPG, and supported by every CMS and image pipeline.
AVIF: the best compression available, but only if your audience uses Chrome, Edge or Safari 17+ — no Firefox encode support yet.
JPG: the compatibility fallback — works everywhere, including email clients, legacy apps and print pipelines.
PNG: master files, screenshots with text, graphics needing transparency, and anything that will be re-edited.

Reproduce it yourself

Open the image converter, drop the same test images, and compare file sizes across formats. Every conversion runs in your browser — nothing is uploaded, and you can verify the numbers independently. The encoder settings match what Optimal Convert uses by default (92% quality for lossy formats).

Frequently asked questions

Is WebP really smaller than JPG?

Yes — at the same visible quality, WebP is typically 25–35% smaller. The savings come from a more efficient compression algorithm (VP8/VP9-based) that predicts pixel blocks better than JPG's 1990s-era DCT approach.

Is AVIF better than WebP?

For compression, yes — AVIF is typically 20–30% smaller than WebP at the same quality. The trade-off is browser support: AVIF encodes in Chrome, Edge and Safari 17+, but not yet in Firefox.

Why is PNG so much larger?

PNG is lossless — it stores every pixel exactly. That makes it the largest common format for photos, but the right choice when you need exact pixels, transparency or a master file to re-export from.

Can I test this myself?

Yes — open the [image converter](/convert/images), drop the same images, and compare file sizes. Every conversion runs in your browser, so you can verify the numbers independently.

Convert it

Each conversion runs in your browser — free, unlimited, and nothing is uploaded.

JPG to WebP PNG to WebP All image converters

Ready-made social images for this post — sized for Facebook/Open Graph, Instagram and Pinterest. They match the card link previews show, and the same art is rendered locally for every format below.

Image format benchmarks 2026 — Facebook · Open Graph share card (1200 × 630 px) — Facebook · Open Graph
og:image — also LinkedIn, X and Slack previews
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Image format benchmarks 2026 — Instagram feed share card (1080 × 1080 px) — Instagram feed
square post · 1080px is Instagram’s native size
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Image format benchmarks 2026 — Pinterest pin share card (1000 × 1500 px) — Pinterest pin
2:3 ratio · Pinterest’s recommended pin size
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What is WebP?

WebP is Google’s image format that makes web images 25–35% smaller with no visible quality loss. A plain-English explainer — and how to convert images to WebP online, free, in your browser.

Read the guide →

PNG vs WebP — which to ship?

PNG vs WebP explained: WebP matches PNG’s losslessness at roughly half the file size. See when to switch — then convert PNG to WebP with a free PNG format converter that runs entirely in your browser.

Read the guide →