pngtowebp.org

Deep dive · 6 min read

PNG vs WebP: a deep dive into image formats

How both formats actually compress your data, where each one wins, and when you should still keep PNG.

Compression: where they really differ

PNG uses lossless compression based on DEFLATE — the same algorithm behind ZIP. It's good at compressing flat areas of colour, but it's bound by the limits of its 30-year-old approach. Every PNG you make is a perfect copy of the source.

WebP is more flexible. Its lossless mode uses a more modern predictor + entropy-coding pipeline that beats PNG by ~26% on the same images. Its lossy mode borrows the intra-frame coder from VP8 (a video codec) — that's how it routinely halves JPEG files at the same quality.

Feature comparison

FeaturePNGWebP
CompressionLossless onlyLossless & lossy
TransparencyYes (8-bit alpha)Yes (8-bit alpha)
AnimationOnly via APNG (limited support)Yes, native
Browser support (2025)Universal~97% of users globally
HDR / wide gamutLimited (no HDR; sRGB common)No HDR (use AVIF for HDR)
Best forSource/master filesWeb delivery

When to use WebP over PNG

For almost every image you put on a public web page, WebP is the better delivery format. Use it when:

When PNG still earns its place

The conversion workflow

Convert in batches with our browser-side tool, or pipe a directory through cwebp if you live in the terminal — see the batch conversion guide for both routes.

Bottom line

PNG hasn't gone anywhere — it's still a great master format. But for images that ship to actual users over a network, WebP is the better default in 2025. The migration takes minutes; the bandwidth and Core Web Vitals wins last.

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