How to Convert PNG to WebP: Cut Your Image Size by 30% or More

Your website loads slowly. Google PageSpeed is yelling at you. Half the problem is your images. And most of those images are PNG files that are way too large.

PNG is great for quality. But it's terrible for page speed. A single PNG can easily be 1-2 MB. Multiply that across a page with ten images and you're at 10-15 MB. Your visitors are waiting. Many are leaving.

WebP fixes this. It cuts PNG file sizes by 30% or more while keeping the same visual quality. And it still supports transparency.

How Much Smaller Are WebP Files Than PNG?

The savings are real and consistent. Here's what typical conversions look like:

Image type	PNG size	WebP size	Savings
Product photo (no transparency)	1.5 MB	180 KB	88%
Logo with transparency	80 KB	22 KB	73%
Screenshot	400 KB	120 KB	70%
Icon set sprite	200 KB	55 KB	73%
Infographic	900 KB	250 KB	72%

The biggest savings come from photographs stored as PNG. This is one of the most common mistakes on the web. Photos should never be PNG. They should be WebP, AVIF, or at minimum JPG. A photo in PNG format is 5-10 times larger than it needs to be.

Even for images that genuinely need PNG (transparent graphics, icons, screenshots), WebP delivers 25-35% smaller files while keeping transparency intact.

Does WebP Support Transparency Like PNG?

Yes. This is one of the most important things about WebP. You don't have to choose between transparency and small file sizes.

WebP supports full alpha channel transparency. Fully transparent areas, partially transparent areas, smooth anti-aliased edges. Everything that works in PNG works in WebP.

The difference is size. A transparent PNG logo at 80 KB becomes a transparent WebP at 20 KB. Same logo. Same transparency. 75% less data.

This matters a lot for websites that use many transparent images. E-commerce sites with product cutouts. Sites with custom icons and UI elements. Any page where images float on top of backgrounds.

Will WebP Work in All Browsers?

Yes, for all practical purposes. WebP is supported by Chrome, Firefox, Safari, Edge, and Opera. That covers over 97% of web users worldwide.

Safari added WebP support in 2020. That was the last major holdout. Since then, WebP has been safe to use everywhere.

The only users who can't see WebP are on very old browsers. Internet Explorer doesn't support it. Neither do browsers from before 2020. If your audience includes these users, you can set up a fallback using the HTML <picture> element. Serve WebP to modern browsers and PNG to old ones.

For most websites in 2026, you can safely use WebP without any fallback. The browser share that doesn't support it is well below 3%.

How Do You Convert PNG to WebP?

ConvertIMG converts PNG to WebP right in your browser. Drop your PNG files in, choose WebP, set your quality, and download. No server uploads. No sign-up. Your files stay on your device.

Quality settings matter for WebP. Here's what to use:

90-95% for images where quality is critical. Portfolio work, hero images, product close-ups. Files are still much smaller than PNG.

80-85% for general web images. This is the sweet spot. The quality difference from 95% is invisible at normal viewing distances. File sizes drop significantly.

70-75% for thumbnails, background images, and decorative graphics. At small sizes or behind text, high quality is wasted. Save the bytes.

Lossless mode for cases where you need pixel-perfect WebP. Logos, icons, and technical diagrams can be converted to lossless WebP. Files are still 25-30% smaller than PNG, with zero quality loss.

Should You Replace All Your PNGs With WebP?

For web delivery, yes. There's almost no reason to serve PNG files on a website in 2026. WebP gives you the same quality at a fraction of the size. Your pages load faster. Your hosting bill drops. Your search rankings improve.

There are a few exceptions:

Favicons. Some browsers still expect PNG favicons. Keep those as PNG.

Social media preview images. Open Graph and Twitter Card images are sometimes better as PNG or JPG. Not all social media crawlers handle WebP perfectly.

Source files for editing. Keep your original PNG files in your project assets. Use WebP for the deployed versions only. If you need to edit an image later, start from the PNG source.

For everything else, convert to WebP. The transition is straightforward. Replace each PNG with its WebP version. Update your HTML img tags. Done.

If you're using a CMS like WordPress, many plugins can automatically serve WebP versions of your uploaded images. You don't even need to change your content.

What About Using AVIF Instead of WebP?

AVIF goes even further than WebP. It produces files that are 20-30% smaller than WebP at the same quality. If you want the absolute best compression, AVIF is the winner.

But WebP has two advantages over AVIF:

Wider support. WebP works in 97%+ of browsers. AVIF is at about 93%. The gap is small but real.

Faster encoding. Converting PNG to WebP is faster than converting to AVIF. For large batches, the speed difference matters.

The ideal setup for a website: serve AVIF first, WebP as the fallback, and PNG (or JPG) as the last resort. But if you're picking one format, WebP is the safest bet. It's supported nearly everywhere and gives you massive savings over PNG.

For a deep dive on all major formats and when to use each, read our image format guide.

Ready to Shrink Your PNGs?

Stop serving bloated PNG files on your website. ConvertIMG converts PNG to WebP in seconds. Free, private, works in your browser. Drop your files in and watch your image sizes shrink.