WebP vs JPG: which is smaller?

The numbers: same photo, matched quality

Quality scales are not directly comparable between formats, so these were matched by visual inspection — zoomed in, no visible difference. Typical results for a 1600×1200 photograph:

JPG at quality 80: ~280KB. The baseline everyone knows.
WebP at quality 80: ~190KB. Roughly one-third smaller than the JPG.
AVIF at quality 60: ~150KB. Nearly half the JPG's size.

These are typical values, not guarantees — a noisy low-light photo compresses worse in every format, and a simple graphic compresses better. The ranking stays the same though: AVIF smallest, WebP in the middle, JPG largest, at equal visual quality.

Why WebP files are smaller

WebP uses a newer compression design (derived from the VP8 video codec) that predicts image content more efficiently than JPG's 1990s-era DCT approach. It also does two things JPG cannot: transparency like PNG, and animation like GIF — both at much smaller sizes than those older formats. For a website, that means one format can replace three.

When JPG still wins

Smaller is not always better. JPG wins on compatibility: every device, browser, printer driver and government upload portal made in the last 30 years accepts JPG. Some exam and visa portals explicitly reject WebP uploads — for those, convert to JPG first and check the exam photo size guide for the exact limits. JPG also renders progressively on slow connections, showing a blurry preview that sharpens, which some readers prefer.

Rule of thumb: if a human or an old system will open the file, use JPG. If a modern browser will display it on a website, use WebP.

When WebP wins

WebP is the right default for anything displayed on the web: blog images, product photos, thumbnails, hero banners. A page whose images are one-third smaller loads visibly faster on mobile data, and page speed feeds directly into both user experience and search rankings. WebP also handles transparency at a fraction of PNG's file size — a logo with a transparent background that needs 400KB as PNG is often under 100KB as WebP with no visible difference.

Browser support in 2026

WebP is supported by every modern browser — Chrome, Edge and Firefox since 2018–2019, Safari since 2020. Unless your audience uses very old software, support is a solved problem. AVIF support is also broad now (all major browsers since 2021–2022), but encoding is slower and a few tools still choke on it, so WebP remains the safer modern choice for general use.

Where AVIF fits

AVIF compresses better than WebP — often 20–30% smaller again at the same quality — but it encodes much more slowly and is less universally supported in desktop software. Use AVIF for large hero images where every kilobyte counts and you control the delivery; use WebP everywhere else. SizeMint reads and writes AVIF alongside JPG, PNG and WebP, so you can compare all three on your own photo in seconds.

Convert between formats in SizeMint

1. Drop in your image

Open the SizeMint compressor and add a JPG, PNG, WebP or AVIF file. Everything runs in your browser — nothing is uploaded.

2. Pick the output format and target size

Choose WebP for web use or JPG for maximum compatibility, then enter an exact target size. The compressor finds the best quality that fits, so you can compare formats at the same byte budget honestly.

3. Compare before you commit

Convert the same photo to both formats at the same target size and zoom into fine detail — foliage, fabric, text edges. Keep the version that looks better; the numbers above are typical, but your photo is the final judge.

Frequently asked questions

Is WebP always smaller than JPG?

At matched visual quality, yes — typically 25–35% smaller for photographs. For tiny thumbnails under a few kilobytes the difference shrinks, and for simple graphics PNG or WebP-lossless may beat both.

Will WebP work everywhere?

In browsers, yes — all modern ones support it. In desktop software, old portals and some government forms, no: a few still reject WebP. When in doubt, submit JPG.

Should I convert all my JPGs to WebP?

For images served on a website, yes — it is one of the cheapest speed wins available. For archival photos, keep the originals; every re-encode between lossy formats loses a little detail.

What about AVIF vs WebP?

AVIF files are smaller but slower to encode and slightly less supported. WebP is the practical default in 2026; AVIF is the specialist choice for maximum compression.

Related guides

For transparency and graphics, read how to compress PNG without losing quality. Hitting an exact limit? See how to compress an image to 20KB.