A file with the .webp file extension is a file format developed by Google to reduce the size of images without having to sacrifice quality for storage space. WebP images are designed to make the web faster, with smaller, richer photos for developers to use.
What Is a WebP File?
WebP (pronounced Weppy) format is the sister project of WebM video container format---based on the VP8 video codec developed by On2 Technologies---released by Google. Google acquired On2 Technologies on February 19, 2010, then released WebP in September of the same year.
With 60%-65% of bytes on most web pages being images, Google set out to create a free, open-source file format that stores both lossy and lossless compression formats in high-quality. While maintaining quality but reducing the size of images, pages load faster, use less bandwidth, and save battery power---especially on mobile---when pages use WebP images.
WebP uses predictive compression to encode an image that checks the values in neighboring blocks of pixels to predict the values in a block, and then it only encodes the difference between them. This allows pixels to be copied multiple times throughout a single file, and redundant data is removed from each block. Saving only the data that changes between each block reduces storage space compared to PNG and JPEG formats. You can learn more from the official WebP compression techniques reference page.
WebP lossless images are 26% smaller than PNG files and up to 34% smaller than lossy JPEG files at an equivalent structural similarity (SSIM) quality index.
How Do I Open One?
Because WebP is developed by Google and royalty-free, it has already been integrated into lots of applications and software you might already have on your computer. Most web browsers already have the required plugin to handle the format.
WebP images are designed for the web and are almost indistinguishable from JPEG and PNG, so you may not have even noticed that's what you were looking at. You can save a WebP image to your computer the same way you would any other image on the internet; right-click the image and click "Save Image As."
Choose a destination on your computer where you want to save the image, then click "Save."
If you have Chrome, Firefox, Edge, or Opera, all you have to do is double-click the image, and it opens in your default browser for you to view.
You can edit WebP files using graphics software, like GIMP, ImageMagick, or Microsoft Paint, which natively open WebP files by default. On Windows, right-click the image, point to "Open With," then choose the program you want to edit with.
IrfanView, Windows Photo Viewer, and Photoshop all require plugins to open WebP images.
You can always change the default application for a file type should you want to open the file with a different program altogether on Mac and Windows. Or, just use Google Chrome to download WebP images as JPEG or PNG in the first place.
