WebP vs PNG: Which Format Should You Use?
One is up to 90% smaller for photos; the other keeps every pixel perfect. Here's how to choose.
WebP vs PNG looks like a format war, but it's really a question of what you're trying to do. PNG is lossless — every pixel is stored exactly, at the cost of a big file. WebP is a modern format that can be lossy (much smaller, visually identical) or lossless (still smaller than PNG).
The short answer: for photos and most web images, WebP wins by a mile — often 90% smaller than the same image as PNG. For graphics that must stay pixel-perfect (logos, screenshots, icons), PNG's lossless guarantee still matters. Below we break it down with real numbers.
Size: WebP crushes PNG
This is the whole ballgame. PNG compresses images losslessly, which means a photograph — full of gradients and fine color detail — barely shrinks at all. A 4MB photo saved as PNG stays around 4MB.
The same photo as a lossy WebP? Roughly 300–400KB — about 90% smaller, and visually indistinguishable at normal viewing sizes. Even lossless WebP is typically 20–30% smaller than the same PNG, because WebP's lossless encoder is simply more efficient.
Put another way: if you're serving photos on a website, choosing PNG over WebP means shipping 10× the bytes for the same picture.
Transparency: both do it, differently
A common myth is that PNG is the only format that supports transparency. Not true — WebP supports transparency too (8-bit alpha), and it can carry it in lossy mode, which PNG cannot.
The real difference is fidelity. PNG's alpha channel is lossless and has been the de-facto standard for two decades, so it's rock-solid everywhere. WebP's lossy transparency can introduce slight edge artifacts on high-contrast transparent graphics.
Rule of thumb: for logos and icons where a crisp transparent edge matters, keep PNG. For photos or large graphics that happen to need transparency, WebP is fine and far smaller.
Quality and artifacts
PNG's quality story is simple: it's lossless, so quality is always 100% — but you pay for it in file size.
WebP's quality story is a tradeoff you control. At a lossless setting, WebP is also 100% quality and still smaller than PNG. At a lossy setting (say, quality 80), a photo is visually indistinguishable to almost everyone, and the file shrinks dramatically.
The one place PNG genuinely wins on quality is sharp edges and text. Lossy WebP — like lossy JPEG — introduces slight "ringing" around high-contrast boundaries. So a screenshot or diagram with small text is better as lossless PNG (or lossless WebP).
When to use which — the verdict
• Photos on a website → WebP. You'll cut 80–90% off the file size with no visible loss. • Screenshots, diagrams, text-heavy images → lossless PNG (or lossless WebP). Sharp text and hard edges stay crisp. • Logos and icons with transparency → PNG. Lossless alpha is the safe, universally-compatible choice. • Anything you're not sure about → WebP lossless. It's strictly smaller than PNG at identical quality.
You can convert between these in your browser with CompressFast — no upload, no account. Convert PNG to WebP (or back) in seconds and compare the sizes yourself.
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FAQ
Is WebP better than PNG?
For most web images, yes. Lossy WebP is typically 80–90% smaller than PNG for photos with no visible quality loss, and even lossless WebP is 20–30% smaller than PNG at identical quality. PNG's edge is its rock-solid lossless transparency for logos and icons.
Is WebP or PNG better for transparency?
Both support transparency, but PNG's lossless alpha is more universally compatible and artifact-free. For logos and icons with crisp transparent edges, use PNG. For photos or large graphics that just happen to need transparency, lossy WebP is fine and much smaller.
Does converting PNG to WebP lose quality?
Not if you use lossless WebP — it re-encodes with zero pixel change and is typically 20–30% smaller. If you use lossy WebP for a photo, the quality loss is invisible at normal viewing sizes while the file shrinks by ~90%.
Should I use WebP or PNG for screenshots?
Screenshots contain text and sharp UI edges, which lossy compression tends to artifact. Use lossless PNG, or lossless WebP if you want a smaller file with identical quality.
Can I convert PNG to WebP in the browser?
Yes. Tools like CompressFast convert PNG → WebP (and WebP → PNG) entirely in your browser — no upload, no account. Drop the file, pick the format, download the result.