Convert PNG to WebP
The editor above is set to export WebP. Drop in a PNG and you will normally see the file size fall by half or more, with transparency intact. The conversion runs on your device — the PNG is never uploaded.
Why PNG files get so large
PNG is lossless: it reproduces every pixel exactly, which is why it is the right format for screenshots, logos and anything with hard edges. The cost is that it has very little room to be clever about photographs.
Its compression works by predicting each pixel from its neighbours and storing the difference, then packing those differences with the same general-purpose algorithm used by ZIP files. That is superb for large areas of identical colour — a flat UI background compresses to almost nothing — and close to useless for a photograph, where no two adjacent pixels are ever quite the same. A photo saved as PNG routinely takes five to ten times the space of the same photo as JPEG or WebP.
PNG also has two quite different modes. Palette PNGs store up to 256 colours and are small; truecolour PNGs store 16 million and are not. Most screenshot tools and design exports produce truecolour, which is why a simple-looking screenshot can still be several megabytes.
Scrolling captures are the extreme case. A whole web page grabbed with a scrolling screenshot tool such as GrabCanvas can be many thousands of pixels tall, and the PNG grows with every one of them. WebP stops at 16,383 pixels on either side, so a capture taller than that has to be cropped into parts before it can be converted.
What you gain
| Kind of PNG | Export | Typical saving |
|---|---|---|
| Photograph saved as PNG | WebP quality 80 | 85–95% |
| Screenshot with text | WebP quality 90 | 50–85% |
| UI element, flat colour | WebP quality 100 (lossless) | 20–30% |
| Logo with transparency | WebP quality 100 (lossless) | 20–30% |
| Already-optimised palette PNG | WebP | little or none |
The quality slider on this page starts at 90 rather than 80, because PNG sources are more often graphics and screenshots than photographs, and text edges are the first thing to suffer from aggressive compression.
Lossless WebP, at quality 100
This is the part most converters do not tell you. WebP is two formats sharing one file extension: a lossy one related to video compression, and a lossless one designed to compete directly with PNG.
The browser encoder CropShrink uses switches between them at the top of the range. At quality 100 you get lossless WebP — pixel-for-pixel identical to your PNG, typically 20–30% smaller. Below 100 you get lossy WebP, which is far smaller again but no longer exact.
That gives you a clean decision. If the pixels must be exact — a logo on a brand background, a diagram with hairlines, a screenshot someone will read text from, a QR code — use quality 100 and you lose nothing but bytes. If it is a photograph, drop to 80 and take the much larger saving.
Transparency comes across
WebP supports an eight-bit alpha channel, exactly like PNG, so soft shadows, feathered edges and rounded corners survive the conversion. There is no need to flatten anything or to keep a PNG fallback for transparency alone.
This is the main reason to convert to WebP rather than JPEG. JPEG has no alpha channel at all; exporting a transparent image as JPEG flattens it onto white, which is visible the moment it sits on any other colour. If your image has transparency, WebP and PNG are the only two options here.
Browser support, and when not to convert
WebP is supported by every major browser released since 2020 — Chrome, Edge, Firefox, Safari 14 and later, and the mobile versions of all of them. For a public web page in 2026 you can serve WebP without a fallback and not think about it again.
Outside the browser it is patchier, and that is where the exceptions live:
- Email attachments. Desktop mail clients and the software your recipient opens them in may not handle WebP. Send JPEG or PNG.
- Print and design handoff. Print shops and older design tools expect JPEG, PNG or TIFF.
- Upload forms that list accepted types. If the form says JPG or PNG, it means it.
- Documents and presentations. Office software support is recent and inconsistent across versions.
The AVIF vs WebP guide covers the newer alternative. For those, compress as JPEG or PNG instead — the same editor, a different format in the export panel.
One last note on metadata: converting re-encodes the image through the browser, which writes no EXIF. Camera details, timestamps and GPS coordinates are dropped. That is usually welcome before publishing a photo, but it does mean the WebP is not an archival copy of the PNG. Keep the original.
More image tools
Every one of these is the same editor, opened for a different job — and all of them run on your device.
- Compress an imageShrink a photo for the web, an email or an upload form.
- Compress to 100 KBHit a hard upload limit without guessing at the quality slider.
- PNG to AVIFSmaller again than WebP, transparency intact.
- Resize an imageChange the pixel dimensions with Lanczos3, Catmull-Rom or Mitchell.
- Crop an imageTrim to what matters, freeform or to a fixed ratio.
- Remove EXIF dataStrip the GPS location, camera and serial number from a photo.
Or start from the full editor, which does all of it at once.