PNG to WebP: choose smaller delivery files without guessing
A transparent product cutout and a screenshot have different requirements from a photograph. PNG stores decoded pixels losslessly, which is useful for masters and editing, but it can carry more bytes than a website needs. This converter creates WebP delivery copies locally so you can inspect the tradeoff before replacing an asset. Keep the source PNG: a smaller export is not automatically a better editing master.
Lossy and lossless WebP are different encodes
The WebP format supports both lossless and lossy compression. This tool currently uses your browser’s lossy WebP encoder. Raising its quality setting can retain more visible detail, but even 100% is not a promise of identical decoded pixels. There is no lossless WebP switch here. For exact pixel storage, keep your original PNG or use PNG with Keep exact pixels and original dimensions.
Keep alpha transparency when the layout needs it
Standard WebP conversion supports the source alpha channel, including partially transparent edges. Leave Platform size on Custom size for a transparent logo or cutout. Marketplace presets intentionally place the image on an opaque white canvas; they are unsuitable when the exported background must remain transparent. Preview edges against contrasting backgrounds and inspect small lettering at 100% before downloading.
Where smaller files can help Core Web Vitals
If a hero image is the Largest Contentful Paint element, fewer downloaded bytes can reduce its resource load duration. That can improve LCP, but conversion alone cannot guarantee a Core Web Vitals pass. Server response time, image discovery, rendering delays and connection speed also matter. Serve appropriately sized responsive images, declare width and height, avoid lazy-loading the main LCP image, and measure the deployed page instead of inferring performance from file size alone.
How it works
- Choose original dimensions for a controlled format comparison, or use the 2048px web limit when that resolution fits the intended placement. WebP output is locked on this page.
- Add your PNG batch. Start with a higher quality for diagrams or fine text; use a lower setting only after checking the result. Smaller source images are not enlarged.
- Open a ready row’s preview, compare the original and converted versions at 100%, and inspect gradients, text and transparent edges. Changing settings requires Apply & re-compress.
- Review actual output sizes, choose file naming, then download individual WebP files or the ZIP. Test a representative exported asset in its real website layout before replacing the entire library.
Frequently asked questions
Why can a WebP export still be larger than its PNG source?
A small palette PNG can already be very efficient. WebP container overhead and the chosen quality may produce more bytes. A cross-format request still returns WebP; the size guard does not secretly substitute PNG.
Does WebP conversion preserve PNG metadata or animation?
Re-encoding through the browser exports a still image and does not preserve original EXIF, embedded profiles or animation. Keep the source file when that information matters, and check appearance in the destination application.
How can I verify transparency survived the conversion?
Leave platform presets off, download the WebP, and inspect it on both light and dark backgrounds. A checkerboard preview helps reveal a transparent canvas, while contrasting backgrounds expose halos around semitransparent edges.