Format reference · .webp
What is WebP?
WebP is an image format made for the web. It offers both lossy and lossless compression, supports transparency and animation, and typically produces smaller files than JPG or PNG at similar quality. Every current major browser displays it.
Origin
Google announced WebP in 2010. The lossy mode reused the still-frame coding of the VP8 video codec, which Google had acquired the year before. Lossless compression, an alpha channel and animation were added over the following two years, turning WebP into a single format that can stand in for JPG, PNG and GIF.
Files use a simple RIFF container with chunks for image data, alpha, animation frames, an ICC color profile, EXIF and XMP. The maximum size is 16,383 × 16,383 pixels, which rarely matters for web images but can for large panoramas.
How WebP compresses images
Lossy WebP works on 16×16 blocks. For each block the encoder predicts the pixels from already-decoded neighbors, then stores only the prediction error, transformed and quantized much like JPG. A more efficient entropy coder and a built-in deblocking filter mean heavy compression tends to look soft rather than blocky. Lossy WebP always uses 8-bit color with halved color resolution, which can slightly blur fine red or blue detail.
Lossless WebP is a completely separate codec. It combines pixel prediction, color-space transforms, a small cache of recently used colors and back-references to repeated pixel runs. On graphics and screenshots it usually beats PNG. There is also a near-lossless setting that adjusts pixel values very slightly to compress better.
Transparency and animation
WebP keeps an 8-bit alpha channel in both modes. The useful twist is that a lossy image can carry a losslessly compressed alpha channel, so a product photo cut out from its background can be a fraction of the size of the equivalent PNG.
Animated WebP stores frames that can each be lossy or lossless, with full alpha. For short clips it is usually much smaller than GIF and not limited to 256 colors. Pixellin converts only the first frame of an animated WebP; the GIF vs WebP comparison covers animation in more depth.
Support in 2026
All current browsers display WebP: Chrome, Edge, Firefox and Safari 14 or later. On the desktop, Windows 10 and 11 open WebP in the Photos app, and macOS Preview reads it on recent versions. Most current image editors now open and save it natively.
The friction is elsewhere. Some older desktop software, print services, government portals and upload forms still reject WebP. That is why people often save an image from a website and end up with a .webp file they can’t use. WebP to JPG and WebP to PNG fix that in a few seconds.
File size expectations
Lossy WebP is often 25–35% smaller than a JPG of similar visual quality, and lossless WebP is commonly around a quarter smaller than an optimized PNG. Savings vary with content: smooth, simple images gain most, and very detailed photos at high quality gain less. You can create WebP from any image with Convert to WebP, where the default quality is 85.
Use WebP for
- Photos and graphics on websites, where smaller files load faster
- Cut-out product images that need transparency at a small size
- Short animations that would be large as GIF
- One format for both photos and graphics in a web project
Avoid WebP for
- Sending files to people using older software or print shops
- Upload forms that list only JPG and PNG
- Very large images over 16,383 pixels on a side
- Archival masters that need 10-bit or higher color
WebP questions
Why do images I save from websites come out as WebP?
Many sites serve WebP because it loads faster than JPG or PNG, and your browser saves the file in the format it received. Your browser displays it fine, but other apps may not. Converting the file to JPG or PNG makes it usable in older software and upload forms.
Is WebP lossy or lossless?
It can be either. WebP has a lossy mode that competes with JPG and a separate lossless mode that competes with PNG. Both support transparency. You can’t tell which mode a file uses from the extension; the choice is made when the image is encoded.
Can I open WebP files on Windows and Mac?
Yes, on current systems. The Photos app on Windows 10 and 11 opens WebP, and Preview on recent macOS versions does too. Every current browser can also display a WebP if you drag it into a tab. Older versions of some editors may need an update or a conversion to JPG or PNG.
Should I convert all my website images to WebP?
For most sites it is a safe, worthwhile change, since all current browsers support it and pages get lighter. Keep your original JPG and PNG files as masters. If you want even smaller photos, AVIF often goes further, at the cost of slower encoding.
Does WebP keep EXIF data?
The format can store EXIF and XMP metadata, but many tools leave it out to save space. When Pixellin converts an image to WebP, camera data and GPS are not carried over; the orientation is applied to the pixels so the photo stays upright.