PNGtoWebP
Convert PNG to WebP
Up to 3 files at once, 100 with Pro. Mixed formats are fine.
Converting PNG to WebP does everything PNG does, transparency included, in 25 to 50 per cent less space — and up to 80 per cent less if the PNG was really a photograph. Drop a whole folder above: each file converts on your own machine, keeps its alpha channel, and comes back as a ZIP with the names intact.
Why replace PNG with WebP on a website
PNG is the format people reach for when an image has to be exact: a logo, an icon, a screenshot, a chart, anything with hard edges or a transparent background. It is lossless, so nothing is ever smudged, and it pays for that with size. On a page carrying twenty interface assets, that bill adds up to the number your performance report is complaining about.
WebP is the answer because it is the only widely supported format that covers both jobs. It compresses photographs about as well as JPG and it has a real alpha channel, so the transparent logo that had to be a PNG and the hero photograph that had to be a JPG can both be WebP. One format instead of two, on a site that already has enough moving parts.
How much smaller a PNG gets as WebP
How much you save depends on what the PNG contains, and the range is wide. Screenshots, flat graphics and interface assets typically come down by a quarter to a half. A photograph that somebody saved as a PNG — which happens more often than it should — can lose eighty per cent or more, because PNG is a genuinely poor way to store continuous tone. If your PNGs are large and you are not sure why, that is usually the reason.
Lossy or lossless WebP: which to choose
There is a choice worth making deliberately. WebP has a lossy mode and a lossless one. Lossy is the default and is right for photographs and screenshots, where a small imperceptible loss buys a large saving.
Lossless keeps every pixel exactly as PNG does, and is still smaller than the PNG was. That is the one to use for a logo, an icon set or any graphic with fine hard edges, where a hint of softening around a one-pixel line is visible to the person who drew it even if nobody else notices.
Transparency survives the conversion untouched
The transparency question, which is the first thing people ask when moving away from PNG, simply does not arise: it is preserved, there is no fill colour to choose, and a cut-out image behaves exactly as it did. That is the practical difference between this conversion and PNG to JPG, where transparency has to be thrown away and filled with something.
When to keep the PNG anyway
Two cases. Favicons — browser support for a WebP favicon is patchy and the file is tiny anyway, so it is not worth the risk. And anything a human will be emailed or asked to open outside a browser, where WebP is still occasionally refused by older desktop software.
Everything else on the site can move. Drop a whole build folder at once: each file converts in your browser with its own progress, nothing is uploaded, there is no size limit beyond your own machine, and the results come back as a single ZIP with the names intact.
How to convert PNG files to WebP in bulk
- Drop your PNG files onto this page — a whole folder works.
- Each converts in your browser, transparency and all.
- Take them individually or as one ZIP.
PNG vs WebP: identical picture, smaller file
| PNG | WebP | |
|---|---|---|
| Full name | Portable Network Graphics | WebP Image |
| File extension | .png | .webp |
| Media type | image/png | image/webp |
| Compression | Lossless — nothing is discarded | Either, depending on the setting |
- Quality
- Some quality is given up for a smaller file. At the default setting the difference is hard to see.
- Where it runs
- This conversion runs inside your browser. Your file is never uploaded, and it works with the network disconnected.
PNG to WebP: common questions
- Are my PNG files uploaded anywhere?
- No. This conversion runs entirely inside your browser, so the file never leaves your device. You can confirm it yourself: open the network tab of your browser's developer tools and watch that nothing is sent while the file converts.
- Does WebP keep transparency?
- Yes, fully. WebP has a proper alpha channel, which is the main reason it can replace PNG rather than only JPG. A logo with a transparent background converts without any need to choose a fill colour.
- How much smaller will the WebP be?
- For screenshots, UI assets and flat graphics, usually 25 to 50 per cent. For a photograph that was saved as PNG, far more — often 80 per cent or better, because PNG stores photographs very inefficiently.
- Is converting PNG to WebP lossless?
- It can be. At the default setting a small, invisible amount is given up. WebP also has a lossless mode that keeps every pixel exactly and is still smaller than PNG, which is the right choice for a logo or an icon where edges must stay perfectly crisp.
- Can I use a WebP as a favicon?
- Not reliably. Favicons want ICO or PNG, and browser support for a WebP favicon is patchy. Keep a PNG or an ICO for that one file.
- Do I need a fallback for old browsers?
- In practice, no. WebP has been supported everywhere for years, including Safari. If you support genuinely ancient browsers, a picture element with a PNG source is the standard way to do it.
- Can I convert a whole folder of PNGs at once?
- Yes. Drop as many as you like; each converts separately with its own progress, keeps its name with the extension swapped, and the batch comes back as one ZIP. Because it runs on your machine there is no queue and no daily allowance.