PNG to WebP

About this converter

This free PNG to WebP converter turns a PNG into a modern WebP, keeping transparency intact. The savings here are usually far larger than with JPG — 60–80% is common, and on a photographic PNG it can be more.

Everything runs in your browser — your image is never uploaded to a server.

Why PNG files get so big

PNG is lossless. Every pixel is stored exactly as it was, and nothing is ever thrown away. That is the right trade for some images and a very expensive one for others.

PNG compresses by spotting repetition — runs of identical pixels, patterns that recur. That works beautifully on a logo with six flat colours, a screenshot of a form, or a chart with clean fills. Such an image can compress to a tiny fraction of its raw size.

It works badly on photographs, because a photograph has almost no exact repetition. Every pixel of a sky differs slightly from its neighbour, so there is nothing to collapse, and PNG ends up storing something close to the raw pixel data. This is why a photo saved as PNG is routinely five to ten times larger than the same photo as JPG, with no visible benefit.

An enormous number of oversized PNGs on the web are simply photographs that were saved in the wrong format — very often a screenshot of a photo, since screenshot tools default to PNG.

WebP has two modes, and that is the whole trick

This is what makes WebP such a good replacement for PNG specifically: it can do both jobs.

Lossless WebP keeps every pixel exactly, like PNG, but compresses it better — typically 26% smaller than the same PNG. For a logo or an interface screenshot you get an identical image in a smaller file, with nothing given up at all.

Lossy WebP discards detail like JPG does, but still supports transparency — something JPG has never been able to do. This is the combination that did not exist before WebP. A product photograph with a cut-out background used to mean a huge PNG, because it was the only common format that could hold both a photo and an alpha channel. Now it can be a lossy WebP at a fraction of the size.

Set a high quality value and you get lossless or near-lossless behaviour. Lower it and you trade detail for size, transparency still intact.

Which quality to choose for what

The right setting depends entirely on what kind of image the PNG holds.

• Logos, icons, flat graphics — use the highest quality. These have hard edges and few colours; they compress well anyway and artefacts around edges are obvious.
• Screenshots with text — high quality, 90 or above. Text is where lossy compression looks worst, producing a faint mush around the letters.
• Photographs with transparency — 80–85 is plenty, and this is where the dramatic savings appear.
• Charts and diagrams — high quality. Thin lines and sharp colour boundaries are exactly what lossy compression blurs.
• Large background images — 75–85 is usually fine, since they sit behind other content.

The rule underneath: hard edges and text need high quality; continuous tone does not.

Transparency survives — with one thing to check

WebP supports a full 8-bit alpha channel, the same as PNG. Soft shadows, feathered edges, anti-aliased curves and partial transparency all come through correctly. This is not the crude on/off transparency of a GIF.

The one thing worth checking after converting at a low quality setting is the edge of a cut-out. Lossy compression works on the colour data, and a semi-transparent edge pixel can pick up a faint halo of whatever colour sat behind it in the original. On a clean cut-out at quality 80 or above you will not see it. On a heavily compressed image with a fine feathered edge against a strong colour, you might — so look at the boundary at full size before you ship it.

How to use it

• Upload your PNG — click the upload area or drag and drop a .png file
• Choose the quality — higher keeps more detail; lower makes a smaller file
• Download — save your WebP

Good to know

• The savings are biggest on photographic PNGs. A screenshot of a photo can drop by 90% with no visible change.
• A tiny icon may not shrink. Under a few kilobytes, format overhead dominates and WebP can come out level or slightly larger. Keep whichever is smaller.
• Resize before converting. A 3000-pixel PNG displayed at 300 pixels wastes more bytes than any codec can recover.
• Favicons should stay PNG or ICO. Support for WebP favicons is inconsistent, and the file is tiny either way.
• Email clients are behind browsers. Some still will not render WebP, so use PNG or JPG in an email template.
• Keep the PNG original if the image is a master asset you will edit again.

Common questions

How much smaller is WebP than PNG?

Far more than most people expect. Lossless WebP averages around 26% smaller than the same PNG with pixel-for-pixel identical output. Switching to lossy WebP, which PNG cannot do at all, commonly saves 60–80%, and on a photograph saved as PNG it can exceed 90%. The bigger the photographic content, the bigger the win.

Will my transparent background be preserved?

Yes. WebP supports a full 8-bit alpha channel exactly as PNG does, so soft shadows, feathered edges and partial transparency all survive. This is one of WebP's main advantages over JPG, which has no transparency at all. At very low quality settings, inspect the edge of a cut-out for a faint colour halo.

Should I use lossy or lossless WebP?

Lossless for logos, icons, diagrams and screenshots containing text — anything with hard edges or lettering, where compression artefacts are visible and the file is small anyway. Lossy for photographs, including photographs with transparent backgrounds, where the saving is large and the loss is invisible at quality 80 or above.

Why is my PNG so large in the first place?

Almost certainly because it contains a photograph. PNG stores every pixel exactly and compresses by finding repetition, and photographs contain almost no exact repetition — so there is nothing for it to collapse. PNG is the right choice for flat graphics and screenshots of interfaces, and the wrong one for photographic content.

Can I convert back to PNG later?

Yes, and transparency will survive the round trip. But if you converted using lossy WebP, the detail discarded in that step is gone for good — converting back gives you a PNG of the compressed image, not the original. Keep your PNG masters if you will need to edit them again.

Does WebP work in emails?

Not reliably. Browser support is universal now, but email clients lag well behind, and several still show nothing at all for a WebP. Use PNG or JPG in email templates. The same caution applies to some desktop software, print workflows and upload forms that accept only PNG and JPG.

Is my image sent to a server?

No. The conversion happens entirely inside your browser, so the file never leaves your computer. This matters for screenshots in particular, which often contain names, addresses, account numbers or internal systems.

Related tools

• WebP to PNG — the other direction, keeping transparency
• JPG to WebP — for photographs that have no transparency
• Image Compressor — shrink an image without changing its format
• Background Remover — create the transparency in the first place