Convert PNG to WebP for lighter website images that keep their transparent background. Bulk, free, nothing uploaded.
PNG to WebP is one of the quickest ways to make a website lighter. PNG keeps every pixel exactly, which is great for quality but often heavy: one hero image or product photo saved as PNG can weigh more than the rest of the page. WebP, made by Google for the web, supports transparency like PNG and compresses much better, and every current major browser shows it. This PNG to WebP converter turns your PNGs into WebP right in your browser, up to 30 at a time, and shows the size before and after for each file, so it works as a PNG to WebP compressor too. Below we explain how the conversion works, show our own measured results (including a case where WebP did not win), give quality settings by image type and explain how to use WebP safely on a site.
For each file, the browser decodes the PNG, including its transparency. The picture is drawn at full size onto a see-through canvas (nothing is painted behind it, unlike JPG output) and saved with the browser’s own WebP encoder at the quality on the slider, 92% by default. Width and height don’t change. This is lossy WebP: the encoder simplifies detail you are unlikely to notice, which is where the saving comes from. Before converting, the page checks that your browser can actually write WebP; if it can’t, it says so instead of handing you a wrong file.
Worked example (measured). In our own Chrome test, an 800 × 600 PNG logo with transparent corners was 4.5 KB. As WebP at 92% it became 6.2 KB, bigger than the PNG, with the transparency kept. As JPG it was 17.3 KB and the corners turned white. This is the honest exception: a tiny PNG with a few flat colours is already compressed extremely well. For photos and large graphics, WebP usually wins clearly; Google reports that lossy WebP with transparency typically gives files about 3 times smaller than PNG.
Drop, choose or paste (Ctrl+V) up to 30 PNG images into the box. Add more lets you keep adding.
WebP at 92% is already set. Open More options to move the Quality slider and watch every file’s new size update.
Download each WebP, or Download all (ZIP). banner.png becomes banner.webp, so swapping files is easy.
A WebP is usually much smaller than the PNG it came from, so pages load faster, especially on mobile data.
Logos, icons and product cut-outs stay see-through. No white box appears behind them.
Each row shows the size before and after. If a small PNG doesn’t get smaller, you see it at once and keep the PNG.
Convert 30 images at a time on your own device. No server, no sign-up, no watermark.
No, and it is worth knowing which PNGs gain the most before you convert a whole site. Here is the measured logo case next to Google’s published figures:
| Type of PNG | Expected result as WebP | What to do |
|---|---|---|
| Photo saved as PNG (hero image, banner, product shot) | Much smaller; Google reports about 3× smaller than PNG for lossy WebP with transparency | Convert at 80 to 85% |
| Product cut-out on transparent background | Much smaller, transparency kept | Convert at 85 to 92% |
| Screenshot with text | Usually smaller | Convert at 90 to 92% so text stays sharp |
| Small logo or icon with few flat colours | Can be bigger, as in our 4.5 KB test | Compare sizes; keep the PNG if it is smaller |
| An image that was already a WebP or JPG once | Little gain; old artefacts get saved again | Start from the best original you have |
Open More options to find the Quality slider (50 to 100%). Every time you move it, the whole list is converted again and the new sizes appear, so you can try a few values in seconds. As a starting point:
Pixels matter more than the slider. A PNG that is 4000 px wide but shown at 1200 px on your page wastes most of its bytes in any format. Shrink it first with the image resizer (WebP output works there too), then convert. If a CMS or form needs a file under a fixed size such as 100 KB, the image compressor can target that size in WebP for you.
Be careful with this phrase. WebP has a lossless mode, and Google reports lossless WebP files are about 26% smaller than PNG. This tool, however, uses the browser’s standard WebP encoder with a quality value, which gives lossy WebP. At 92% the difference from the PNG is very hard to see in normal viewing, but the file is not a bit-for-bit copy. For a website that is usually the right trade. For archives, design source files or anything you will edit again, keep the PNG originals and use the WebP only for publishing.
Select a folder’s worth of PNGs (up to 30) and drop them in together, or keep adding with Add more. All files use the same output and quality. When the list says they are ready, Download all (ZIP) saves them in one file. The names stay the same with a new ending, so hero.png becomes hero.webp, which makes replacing files on a site or in a theme folder simple. For a bigger set, save the ZIP, press Clear and drop in the next group. Copy link with these settings saves your quality in a link, so a teammate can convert their batch the same way.
<picture> element, WebP first and PNG as the fallback.If a WebP row shows a bigger size than the PNG, the PNG was already very efficient: few colours, large flat areas, small dimensions. That is what happened with our 4.5 KB logo. Keep the PNG for that image; there is no rule that every file must be WebP. Re-encoding images that were lossy before also gains little: in our test, a 70.2 KB WebP photo saved as WebP again at 92% came out 82.4 KB. Always convert from the best original you have.
Most online PNG to WebP converters upload each image, convert it on a server and let you download the result. This one uses the WebP encoder built into your browser, so the image goes from your disk to a canvas to a WebP file on your disk without ever crossing the internet. That makes bulk conversion fast (no uploads to wait for), keeps unpublished site images and client work private, and after the page has loaded it works offline.
It also refuses to pretend. Every row shows the measured size before and after, including when WebP is bigger, so you decide per image instead of trusting a blanket “up to 80% smaller” claim. The quality is a real encoder setting, not a vague label, and changing it updates every size in the list at once. Copy summary gives you all the before and after sizes as text for your notes or a client report.
For each file the tool measures the PNG’s size, its width and height, and the size of the WebP it made, and shows them in the result list. It also checks once whether your browser can write WebP. The example numbers on this page are from our own tests with this tool in Chrome in October and November 2026.
What we do not do: we don’t run a visual quality score, we don’t offer lossless WebP, we don’t resize unless you use the resizer, and we don’t keep metadata. We don’t collect anything about your images.
| VidHaul | Typical upload-based sites | |
|---|---|---|
| Upload needed | No, uses your browser’s WebP encoder | Yes, every image |
| Bulk | Up to 30 per batch, ZIP download | Often limited on free plans |
| Size before and after | Shown for every file, live as you change quality | Sometimes shown |
| Watermark | Never | Sometimes on free plans |
| Sign-up | Not needed | Sometimes needed for bulk |
| Works offline after loading | Yes | No |
| Privacy | Images never leave your device | Images are usually kept on a server for a while |
Only convert images you own or have the right to use.
Drop your PNG files into the box on this page. WebP is preselected, so the images are converted straight away; click Download or Download all (ZIP).
Yes. Converting a PNG photo or large graphic to WebP at 80 to 92% usually makes it much smaller. Check the size in each row, because tiny, already optimised PNGs can come out bigger.
Yes. WebP supports transparent backgrounds, so logos and icons stay see-through after conversion.
This tool saves lossy WebP at the quality you set. At 92% and above the difference is very hard to see, but it is not bit-for-bit lossless; keep your PNG originals.
Select up to 30 PNG files at once and drop them in. When they are ready, Download all (ZIP) saves them together. For more, press Clear and do the next group.
Yes. It is free with no sign-up and no watermark, and your images are never uploaded.
Some older Safari versions can show WebP but can’t create it. The page tells you if that happens; update Safari or use Chrome or Firefox.