PNG to WebP Converter - Free & Private

Shrink PNG graphics to WebP while keeping every transparent pixel exactly where it is.

🖼️

Drop PNG files here or click to select

Up to 20 files at once. Nothing is uploaded, conversion runs in your browser.

85 to 95 keeps photos looking identical at a much smaller size.

PNG to WebP with transparency intact

WebP keeps the alpha channel, which is the entire point of this conversion. A logo, an icon set or a product cut out on a transparent background stays cut out while the file shrinks hard. Lossy WebP with alpha routinely lands 60 to 80 percent below the equivalent 24 bit PNG for illustrations and interface captures, because the colour data is compressed predictively while the transparency mask is stored separately and losslessly.

Design system maintainers and ecommerce teams gain the most. A catalogue of 400 packshots on transparent backgrounds is easily 900 MB as PNG and under 200 MB as WebP, with the cutouts still landing cleanly on whatever colour a category page happens to use. Game developers shipping sprite sheets, and documentation writers whose PNG diagrams quietly dominate a repository, see the same effect on their own asset folders.

The quality slider only touches colour information. Move it and the edges of a cutout stay exactly where they were, because the alpha mask never goes through the lossy pass. What does suffer at low settings is flat brand colour, which can pick up faint blotches. For artwork with hard edges and few colours, stay at 90 or above; for photographic content with a soft transparent border, 75 is usually invisible even side by side.

WebP is not always the right answer. A flat two colour icon at 32 pixels is better served by SVG, which scales to any display density and often weighs less than either raster format. Very small PNGs, under roughly 2 KB, can come out larger as WebP because of container overhead. And if the asset is heading into a printed brochure or an older desktop publishing package, keep the PNG, because layout software support for WebP is still uneven.

Everything is decoded and re-encoded on your device, so unreleased branding and assets covered by a non disclosure agreement never reach a server. Drop up to twenty PNGs in at once and the tool reports the saving per file, which is handy evidence for a sceptical colleague. Trim empty transparent padding first with the Image Cropper when the export came out of a design tool with a generous canvas, and reach for the App Icon Generator when the same artwork also has to ship as launcher icons.

How the PNG to WebP Converter Works

  1. 01Drop the PNG files you want to shrink into the upload area
  2. 02Leave quality high for hard edged artwork, or lower it for photographic content with soft edges
  3. 03Read the per file saving in the results list, since flat graphics behave very differently from photographs
  4. 04Download the WebP files with their transparency carried straight through

Keeping transparency while cutting file size

WebP stores the alpha channel separately from the colour channels and compresses it losslessly, which is why a cutout stays sharp even when the quality slider sits well below maximum. That split is the reason this conversion behaves so differently from PNG to JPEG, where transparency has to be destroyed before encoding can even start. In practice you can push interface captures and illustrations down to a fifth of their PNG size and still have edges that land cleanly on any background colour. The setting that needs care is flat brand colour. Large areas of a single corporate colour can develop faint blotches at low quality, and those are far more noticeable than any softening in a photograph, because the eye has a perfectly uniform reference sitting right next to the defect. If your artwork is mostly flat fills and hard edges, keep quality at 90 or above and accept a smaller saving. If it is a photographic subject with a feathered transparent border, 75 is usually indistinguishable and the file drops much further.

When to Use PNG to WebP Conversion

Use it when a transparent asset is heading for the web and its PNG size is hurting. Product cutouts in a catalogue, interface screenshots in documentation, illustration libraries and sprite sheets are the obvious candidates. Do not use it for icons that could be vectors, because an SVG scales to any screen density and usually weighs less. Skip it for very small PNGs under a couple of kilobytes, where container overhead can make the WebP bigger. And keep the PNG when the asset is going into print layout software or a desktop publishing package, where WebP support is still patchy.

Common Use Cases

  • Compress a catalogue of packshots on transparent backgrounds before uploading them to a storefront
  • Shrink documentation screenshots with transparent rounded corners so a repository stops bloating Image Cropper - Aspect Ratio Presets Free
  • Ship illustration assets to a design system without the multi megabyte PNG payload
  • Prepare sprite sheets and interface overlays for a browser game where load time decides retention
  • Convert exported artwork that also has to become launcher icons App Icon Generator - iOS, Android & Favicon

Expert Tips

  • Crop away empty transparent padding before converting. Design tools often export on a generous canvas and those pixels still cost bytes.
  • Inspect a flat colour area at 100 percent zoom after conversion, because blotching in a brand colour is the first thing a client notices.
  • Keep quality at or above 90 for anything with hard edges and type, and drop to 75 only for photographic subjects with soft borders.

Frequently Asked Questions

Does WebP really keep transparency?→
Yes. Both the lossless and the lossy WebP modes support an 8 bit alpha channel, exactly like a 24 bit PNG. This converter preserves it, which is also why there is no background colour picker on this page: nothing needs flattening.
Why did one of my files get bigger instead of smaller?→
That is normal for very small or very simple PNGs. A tiny flat icon may already be a few hundred bytes, and the WebP container overhead can exceed the compression gain. Compare the two numbers in the results list and keep whichever file is smaller.
Is the transparent edge softened by the quality slider?→
No. The alpha mask is stored losslessly whatever the quality setting, so the shape of the cutout is identical at 60 and at 100. Only the colour information inside the shape is affected by the slider.
Should I use this for icons and logos?→
Only if they are already raster. If you still have the vector source, export an SVG instead: it stays crisp on high density displays, is usually smaller than either raster format for flat artwork, and can be recoloured with CSS.

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