How to Convert PNG and JPG to WebP (Without Making Files Bigger)

WebP is the image format Google built to make web pages lighter. The same picture usually takes up far less space as a WebP than as a PNG or JPG, which is why page-speed tools keep telling you to "serve images in next-gen formats".

But converting an image to WebP does not guarantee a smaller file. We converted five real images (a camera photo, a photo that had already been compressed for the web, a photo saved as PNG, an app screenshot and a small logo) at every quality setting. Some shrank by 88%. One grew by 42% at a perfectly normal setting. The difference comes down to what kind of image it is and one slider.

This guide shows how to convert PNG and JPG files to WebP for free with FileNaut's PNG to WebP and JPG to WebP converters, which setting to use for each kind of image, and how to do it in bulk from the command line.

• To convert one image: open PNG to WebP or JPG to WebP, add the file, click Convert Image, then Download WEBP. It runs in your browser, so the image is never uploaded.
• Screenshots, logos, icons and anything with text: set quality to 100. That makes a lossless WebP, identical pixel for pixel, and in our tests it was also the smallest file.
• Photos: use 75 to 80. Never use 100 for a photo; it made every photo several times larger.
• Check the result: the converter shows the new size against the original. If the WebP is bigger, lower the quality or keep the original.

This works the same on Windows, Mac, Linux, Chromebook, iPhone and Android.

1. Open the converter for your file type: PNG to WebP or JPG to WebP. For BMP, GIF and other formats, use the Image Converter and choose WEBP as the target format.
2. Drag your image onto the page, or click Browse Files.
3. Set the Quality slider. It starts at 80, which suits most photos. Move it to 100 for screenshots, logos and graphics (the next section explains why).
4. Click Convert Image. A typical image takes a second or less.
5. Read the result line. It shows the new size and how it compares with your original, for example "49% smaller than the original". If it says larger, click Change settings and convert again, lower the quality and retry.
6. Click Download WEBP. The file keeps your original name, so Screenshot 2026-10-14 at 11.42.03.png downloads as converted_Screenshot 2026-10-14 at 11.42.03.webp.

Using Safari or an iPhone? Safari can display WebP images but cannot create them: when a web page asks it for a WebP, it quietly hands back a PNG instead (we confirmed this in Safari 26). FileNaut detects that and switches to a WebP encoder built from Google's own libwebp library that runs inside the page, so you still get a genuine WebP and your image still never leaves your device.

Here is what happened when we converted five images at different settings. Sizes are what FileNaut's converter produced; Python's Pillow library, which uses the same libwebp encoder, gave results within 1% of these.

Four rules fall out of that table:

1. Screenshots, logos and graphics: use lossless (100). It was the smallest option for both, and the pixels are identical to the PNG. Lossy settings altered the pixels and, for the logo, made the file bigger.
2. Photos: use 75 to 80. Lossless WebP stores every pixel of a photo exactly, which is why it ballooned to several times the size of a JPG.
3. A JPG that was already compressed may barely shrink. Our web photo saved just 1% at quality 80 and grew 42% at quality 90. Each conversion throws a little more detail away, so you are paying in quality for very little saving. Try 75; if the WebP still is not clearly smaller, keep the JPG.
4. Photos saved as PNG are the big win. A PNG is the wrong format for a photograph, and converting one to WebP at 80 cut it by 88% with no visible difference.

Why the same slider number gives such different results: a JPG's "quality" and a WebP's "quality" are separate scales on separate formats. Google's widely quoted figure, that WebP is 25 to 34% smaller than JPG, compares files of equal visual quality, not files with the same number on the slider.

Yes. Unlike JPG, WebP has an alpha channel in both its lossy and lossless modes. We converted a logo with a transparent background and a transparent hole in the middle: both stayed fully transparent in the WebP, in Chrome and in Safari. If you are converting a transparent PNG for a website, WebP is the format that keeps the transparency and shrinks the file. Converting it to JPG would fill the background with solid white.

Photoshop and GIMP

Recent versions of Photoshop open and save WebP without a plug-in: use File → Save a Copy and choose WebP, then pick lossy or lossless. Older versions need Google's WebPShop plug-in. In GIMP, use File → Export As, give the file a .webp name, and choose the quality in the dialog that follows.

Mac and Windows built-in apps

Both can open WebP files, but neither is a reliable way to create them. On this Mac, the built-in sips image tool lists WebP as a format it can read but not write: asked to convert a PNG, it printed the output path and saved nothing. Use the online converter or one of the methods below instead.

Command line: cwebp

Google's free cwebp tool (part of the libwebp download) is the standard way to convert in bulk:

cwebp -q 80 photo.jpg -o photo.webp
cwebp -lossless screenshot.png -o screenshot.webp

To convert every PNG in a folder on Mac or Linux:

for f in *.png; do cwebp -lossless "$f" -o "${f%.png}.webp"; done

Python (Pillow)

If you have Python installed, Pillow converts in two lines. This is the method we used to double-check the sizes in the table above:

from PIL import Image
Image.open("photo.jpg").save("photo.webp", quality=80)
Image.open("logo.png").save("logo.webp", lossless=True)

Your website platform may already do it

Before converting a whole site by hand, check whether your platform already serves WebP for you. Many image CDNs, e-commerce platforms and frameworks (the Next.js image component, for example) automatically convert uploaded images to WebP for browsers that support it. If yours does, uploading WebP yourself gains little, and keeping your original PNG and JPG files gives the platform the best source to work from. On WordPress, WebP uploads are supported natively, and image-optimisation plugins can convert your existing media library.

Every current version of Chrome, Edge, Firefox, Safari and Opera displays WebP, on desktop and mobile, so for most sites a plain image tag is enough:

<img src="hero.webp" alt="Product photo" width="1200" height="800">

If you must support very old browsers (Internet Explorer, or Safari before version 14), wrap it in a <picture> element with a JPG or PNG fallback:

<picture>
  <source srcset="hero.webp" type="image/webp">
  <img src="hero.jpg" alt="Product photo" width="1200" height="800">
</picture>

Converting the format is only half of making images light. A 4000-pixel-wide photo shown in an 800-pixel column is still five times wider than it needs to be: resize it first, then convert. Our guide to resizing an image covers the dimensions to aim for.

• Keep your originals. WebP is a delivery format. Edit the PNG or JPG master and export a fresh WebP each time, rather than re-editing and re-saving the WebP.
• Convert from the best source you have. A camera original or an uncompressed PNG converts far better than a JPG that has already been compressed once or twice.
• Judge by size and by eye. Look at the converted image at 100% zoom, especially around text and sharp edges, before you replace the original.
• Do not send WebP by email or to print shops. Some email clients, office software and print services still do not accept it. Send JPG or PNG there.
• Animated GIFs need a dedicated tool. FileNaut converts still images, so an animated GIF comes out as a single frame. Google's gif2webp tool, from the same libwebp download as cwebp, keeps the animation.

Open the PNG to WebP or JPG to WebP converter, use 100 (lossless) for screenshots and graphics and 75 to 80 for photos, and check the size line before you download. Photos saved as PNG and screenshots shrink dramatically. A JPG that was already compressed may not, and when the WebP comes out bigger, the right move is to keep the original.