Compress / WebP
Compress WebP Images Online
Shrink WebP files further with an adjustable quality slider. Useful when an exported WebP is still heavier than your page budget allows.
Why Compress WebP Files?
Exports are often too generous
Design tools export WebP at quality 90 or above by default. Dropping to 75 typically halves the file with no visible change.
Already the right format
Compressing rather than converting means you keep WebP's advantages, including the alpha channel, and only trade quality for size.
Page weight budgets
Hitting a Largest Contentful Paint target is usually about total image bytes. This is the last lever before changing the image itself.
Preview before committing
The estimated output size updates as you move the slider, so you can find the point where quality starts to visibly suffer.
What each quality setting actually costs
WebP holds quality well through the first part of the range and then gives way quickly. The step from 90 to 80 removes more than half the remaining bytes for a small measurable change, which is where most of the useful saving lives.
| Measure | Quality 90 | Quality 80 | Quality 70 | Quality 60 |
|---|---|---|---|---|
| File size | 851 KB | 451 KB | 352 KB | 309 KB |
| Saving against the original | 15% | 55% | 65% | 69% |
| Similarity to original (SSIM) | 0.994 | 0.977 | 0.969 | 0.963 |
Measured on a 3840 x 2160 photograph of 1,006 KB, compressed with sharp exactly as this tool does. Transparency is preserved at every setting. If the source WebP was written losslessly, expect larger savings than these, since this test started from an already lossy file.
Questions
Does this compress lossily or losslessly?
Lossily. WebP can do both, and the difference is larger than most people expect: on a photograph, lossless WebP came out at 1,914 KB while the same image at quality 80 was 543 KB, roughly a quarter of the size for a difference you have to hunt for. Lossy is the right mode for compressing a photo, which is what this tool assumes.
Why did my WebP get bigger?
Because lossy WebP is the wrong tool for flat artwork. We measured a flat-colour graphic at 9 KB as lossless WebP and 22 KB at quality 80, so compressing it made it more than twice the size and threw away pixels doing it. Lossy encoding spends bytes describing gradients that a logo does not have. If your WebP is a logo, a screenshot or a diagram, it is probably already close to as small as it usefully gets.
How does WebP compare to JPG at the same setting?
WebP wins clearly. In our format benchmark across 46 images, WebP at quality 80 totalled 17.4 MB against 30.1 MB for JPEG at quality 80, at essentially the same measured similarity to the original, 42.1 dB against 42.3 dB. Roughly 40% fewer bytes for the same picture.
Will transparency survive?
Yes. WebP keeps its alpha channel through lossy compression, which is one of the real advantages it has over JPEG.
Are my files uploaded?
Yes. Compression runs on our server rather than in your browser, files are processed in memory and discarded when the download starts, and each one counts against the daily limit.
This one comes to our server
A browser cannot do this one, so the file is uploaded, held in memory, converted, returned and discarded. Nothing is written to disk and there is no account to attach it to.
What the privacy policy saysFurther reading
Benchmark11 minI ran a real photo corpus through every format this site outputsPNG, JPG, WebP, AVIF, GIF and PDF, measured on the same images with the same pipeline, including the PSNR that shows which ones actually kept the pixels.Trim your WebP files
Adjust quality, preview the size, download.