PNG to WebP converter
This page turns a lossless PNG into a WebP file that still supports transparency, so you can shrink screenshots, icons and hero graphics without the flat background a JPG would force on you. The tradeoff is that WebP encoding is lossy: pixels you did not keep are gone, so check the result before replacing the PNG you exported.
Compression is lossy; very fine detail can soften at lower quality.
Processed on your device. Files aren’t sent anywhere.
When WebP is the right target for a PNG
PNG is already efficient for flat colour, but it is rarely the smallest format for a screenshot with gradients, shadows or photographic regions. WebP compresses those areas much harder, and it keeps an alpha channel, so a rounded card or a cut-out logo stays transparent instead of being flattened onto white.
Use this route when the image is going on a page and nobody needs to edit it later. If the PNG is your master copy - the file a designer will reopen in an editor - keep the PNG and convert a copy for delivery. WebP is a delivery format, not an archive format, and some desktop tools still cannot open it.
- Good fit: screenshots, UI mockups, banners, icon sets, photos embedded in a PNG container
- Keep PNG instead: logos you will edit, images with text you must zoom at 400%, archival exports
- Keep PNG instead of WebP when the file is already tiny; re-encoding can make it bigger
Transparency survives, the pixels do not
The canvas keeps an alpha channel when the output is PNG or WebP, so partially transparent edges blend the same way. What changes is the colour data inside opaque pixels: WebP is a lossy codec, and at low quality you will see soft banding around gradients and mushy texture in photographic areas.
Because the PNG source was lossless, every detail you discard here is discarded for good. There is no way to recover it from the WebP later.
Browser encoding support
Encoding to WebP is done by your browser, not a server. If the browser cannot encode WebP, the page reports that the format is unsupported in this browser rather than sending your file somewhere else. Decoding a PNG works everywhere, so the input side is not the risk.
Files never leave the device: the conversion runs on a canvas in this tab.
The quality setting is an encoder knob, not a savings percentage
The quality control runs from 40 to 100, starting at 85. It is passed to the browser's WebP encoder; it is not a percentage of the original information kept, and it does not apply to PNG output at all.
Start at 85 and step down only if the file is still too large. Below roughly 60-70, gradients and small text start to break up. The only reliable test is opening the result next to the source at full zoom.
- 85 (default): usually a good balance for screenshots and graphics
- 70-80: when you need a smaller payload and can accept slightly softer edges
- 40-60: previews and thumbnails where detail does not matter
- A smaller number does not guarantee a smaller file for noisy or photographic content
Do not assume WebP is always smaller
Flat, simple PNGs can come out larger as WebP than they were as PNG. That is a normal outcome, not a bug. Compare the byte sizes before you swap files in a project, and keep the PNG if the WebP did not win.
This converter does not promise a compression ratio; it shows the file it produced.
Size steps: Original, 75%, 50%, 25%
The Size control is a four-step segmented choice, not a slider. Original keeps the pixel dimensions exactly; 75%, 50% and 25% scale the drawing before encoding, using high-quality smoothing.
Resizing is often the bigger win: a 2400px screenshot downscaled to 50% loses far more weight than any quality tweak. Do the resize and the WebP encode in one pass here rather than resizing elsewhere first.
- Original: same width and height, only the encoding changes
- 75%: mild downscale for dense screenshots
- 50%: typical for cards, thumbnails and hero images on small screens
- 25%: preview tiles; small text becomes unreadable
Pixel ceiling
Each input file may be up to 25 MiB and you can add up to 10 files at once. The engine refuses an image only when both the source and the scaled output exceed 40 megapixels, so 8000x5000 sits exactly on the boundary and a large source scaled to 50% still converts.
What the output file actually contains
The result is a fresh WebP drawn from pixels: the file is named after your original with the extension changed, and its metadata reports the output width and height. ICC profiles, EXIF data and PNG text chunks are not carried over, so colour labels and camera details disappear.
Animated PNG is not assembled frame by frame; the browser hands the canvas the first frame, so an animated source becomes a single still image.
- Kept: pixel content, alpha transparency, output dimensions
- Lost: colour profile labels, EXIF, alt text you embedded in PNG metadata, animation
- Not touched: the original file on your disk - nothing is overwritten
Batch without uploading
Drop several PNGs and one setting set applies to the whole batch; each output is downloaded separately. Everything runs locally in the browser, so there is no account, no queue and no server copy of your images.