JPG to WebP Converter

That depends mostly on how the JPG was saved. Photos straight from a camera or phone are stored at high quality and shrink a lot; JPGs already compressed for a website shrink less. Measured with this converter, 22 detailed photos saved as high-quality JPGs (3.0 MB in total) came out like this:

Part of each saving comes from compressing again at a lower quality, which a new JPG would give you too. WebP’s own advantage is the gap between the columns: matched for how close they stayed to the originals, the WebP files were about 25–30% smaller than the JPGs. That agrees with Google’s published figure for WebP of 25–34%.

Smooth pictures shrink the most. A 1600 × 1200 landscape with a clear sky went from 193 KB to 35 KB at 85%, while the same photo re-saved as a JPG at 85% was still 154 KB.

• 85% (the default): the closest match. In the test above, WebP at 85% stayed nearer the originals than JPG at 85% and was still 13% smaller.
• 75–80%: a good choice for photos on web pages, where a smaller file means the page appears sooner, especially on a phone connection.
• 60–70%: for thumbnails and small previews, where fine detail matters less.
• 100%: avoid it for JPGs. In Chrome, Edge and Firefox it makes a lossless WebP, which stores the JPG’s pixels exactly, compression artefacts and all: the 3.0 MB of test photos became 7.3 MB.

To judge a setting, convert one photo and open the original and the WebP in Compare Two Images, which has a before/after slider.

• Start from the best copy you have. A JPG that has been saved several times, or downloaded from social media, has already lost detail. WebP keeps what’s left but can’t restore it.
• Already heavily compressed JPGs need a lower setting. Photos saved as JPG at 60% came out a third bigger as WebP at 85%, and only slightly smaller at 75%. For those, 75% or lower is the useful range.
• Resize before converting. A 12-megapixel phone photo is 4,000 pixels wide, and most web pages show it at 2,000 or less. Resize it to the display size first: fewer pixels save more than any format.
• Sideways phone photos come out upright. Photos stored on their side with a rotation tag are turned the right way.
• Camera details aren’t copied. The date, camera model and GPS location in a JPG’s EXIF data are left out of the WebP. To see what a photo contains first, use the EXIF viewer.

WebP is made for web pages, and every current browser shows it. Elsewhere, JPG is still the safer choice:

• Sending photos to people: a JPG opens on every phone and computer, while a WebP may not open in someone’s email app or photo viewer.
• Printing: photo-printing services and print shops usually ask for JPG.
• Upload forms: job applications, official forms and online marketplaces often accept only JPG or PNG.
• Your originals: keep the camera JPGs and convert copies for your website.

Converted a photo you now need as JPG? The WebP to JPG converter turns it back, though each conversion loses a little more detail, so it’s better to go back to the original.