PNG to WebP Converter

What does PNG to WebP conversion do, and what does this tool add?

PNG to WebP conversion turns a lossless PNG file into Google's WebP format. Most people do it to keep the same picture in a smaller file, so a web page opens faster. The tool on this page works inside your browser, which means your file never leaves your device, and the page uploads and stores nothing.

Here is what the tool does:

• It detects the input itself: It reads the format from the first bytes of the file and ignores the extension. As a result, a file with a wrong extension still opens correctly.
• Transparency stays intact: Transparent areas in the PNG stay transparent in the WebP.
• The output is lossy WebP: The quality slider starts at 92% and you can change it at any time.
• The pixel size stays the same: Width and height do not change, so use the image resizer if you also need smaller dimensions.

We run this conversion before launch in our web design projects, because transparent PNGs exported from design files are often the heaviest assets on a page. For the wider picture, read our guide on how to optimize images for website speed and SEO.

Does PNG to WebP make your site faster?

Yes, usually. Images are the heaviest files on most pages, so shrinking them is one of the most direct ways to speed a page up. According to Google's WebP documentation, lossless WebP images are 26% smaller than PNGs. Google also reports that lossy WebP images are 25-34% smaller than comparable JPEG images at the same SSIM quality index.

Google adds that when lossy compression is acceptable, WebP with transparency typically gives files 3 times smaller than PNG. That is exactly the case this tool covers, so the figure applies to your files. Still, these are typical values, so your own result depends on the image.

A smaller file helps in three places:

• Load time: The largest element on a page is often an image, so image weight feeds straight into LCP, one of the Core Web Vitals.
• Mobile data: Visitors download less, which matters because slow connections feel every extra kilobyte.
• Rankings: Speed alone does not decide rankings, but the effect of site speed on SEO shows up through user experience.

In short, PNG to WebP will not work miracles on its own. On a page full of design exports, however, it is one of the cheapest wins available.

Does transparency survive when you go from PNG to WebP?

Yes, it does. That works because WebP supports an alpha channel, which carries the transparent areas. Google's documentation says lossless WebP supports transparency at a cost of just 22% additional bytes. In this tool, therefore, the transparent background, semi-transparent shadows and soft edges of your PNG stay in place in the WebP file.

This is the main difference from JPG. JPG cannot hold transparency, so with JPG as the target the tool fills transparent areas with white, black or a custom colour. A WebP target needs no fill. If you use a logo on both light and dark backgrounds, WebP is therefore the better choice.

One warning applies. When quality drops, lossy compression degrades the boundary lines and soft shadows of a transparent image first. Then, after you download, open the file at real size on a white and on a dark background. If you see halos or jagged edges, raise the quality. For places that need JPG, use the PNG to JPG converter.

How does the quality slider change WebP file size?

This tool writes lossy WebP, and there is no lossless WebP option. The quality slider starts at 92%. However, lowering it shrinks the file and removes detail. For that reason the WebP output does not match your PNG pixel for pixel. On most images you will not spot the difference, yet hard-edged artwork and small text show it first.

To find the balance, try this order:

1. First, leave quality at 92% and look at the before and after size in the row.
2. Second, if the saving is too small, lower the slider in small steps. The tool converts the list again after every change.
3. Then download the result and open it at real size, because the row preview is small and hides flaws.
4. Finally, if you see banding in gradients or halos around edges, go one step back.

If you switch the target to PNG, the slider disappears, because PNG is lossless and takes no quality setting. Also keep your original PNG. Converting a lossy WebP back to PNG does not restore the detail you lost.

When does it make sense to convert logos, icons and product images?

Not every PNG should become a WebP. The image type and the place you use it decide:

• Large logos and transparent graphics: WebP is a good choice for display on a website. If you own the logo as a vector (SVG), that is often the better format for simple line logos.
• Product photos: Cut-out product shots and white-background images give the biggest saving. A shop page can hold hundreds of them, so the gain adds up. See our ecommerce consulting page and the product page guide.
• Blog images and screenshots: WebP pays off for photo-heavy pictures. For text-heavy screenshots, however, check the letter edges.
• Very small icons: If the file is only a few KB already, the gain is also small. Instead, look at the change percentage in the row.

Some PNGs should stay PNG: source files for print, designs you will edit again, and artwork that needs pixel precision. In short, treat WebP as the publishing copy and PNG as the archive copy.

Do WordPress and browsers support WebP?

Yes, they do. Since version 5.8, WordPress lets you upload WebP images to the media library and use them like JPG or PNG. Your server's image library (Imagick or GD) can affect some details; for example, the Site Health screen shows which formats it supports. If you are still choosing a platform, read WordPress vs custom website.

Browser support is also solid. According to MDN, Chrome, Edge, Firefox, Opera and Safari all display WebP. Safari has two conditions: it must be version 14 or later, and on macOS it needs Big Sur (11) or newer.

Saving, however, needs a short note. The tool creates the WebP file with your browser's own encoder. If your browser cannot save WebP, the tool says so openly and does not quietly hand you another format. In that case, open the page in another current browser.

How do you prepare a fallback for older systems?

A fallback is a PNG or JPG copy you keep ready for places that cannot open WebP. Some forms, email apps and older programs may reject WebP, so read the upload rules first.

Two routes work:

• Fallback inside the page: As MDN suggests, wrap your image in a <picture> element, put a <source type="image/webp"> first, and add the PNG or JPG as the plain image. Browsers that understand WebP use it, and the rest use the fallback.
• Fallback as a file: Instead, convert the same image again with PNG or JPG as the target. For the way back, the WebP to PNG converter is ready too.

Never delete the original PNG. Keep the file name and alt text the same; in our SEO consulting work we see that they tell search engines what the image shows, whatever the format. Because the extension changes, the image address changes too, so update every page that still points to the old address.