How to use it
- Click Choose files or drop your pictures on the box. You can also paste one with Ctrl+V.
- Choose an Output format. Same as the original keeps each file's own format.
- Move the Quality slider. Lower values give smaller files with more visible loss.
- Optionally set a Maximum width or Maximum height in pixels, then click Compress images.
- Slide the comparison to check the first picture, then download each file or all of them as a ZIP.
What the quality setting does
JPEG and WebP are lossy: the encoder throws away the detail the eye is least likely to miss, and the quality setting decides how much. For photographs the usual range is 75 to 85; much lower, and blocks and smeared edges start to show.
PNG is lossless, so the quality setting does not change it. To make a PNG smaller, choose WebP or JPEG, or reduce its size. AVIF usually gives the smallest files at the same look, where your browser can write it, but it takes longer to encode.
Metadata and the rule that a file never grows
Re-encoding writes a new picture from its pixels only, so camera, date and GPS information are not carried into the copy. The rotation of a phone photo is applied to the pixels first, so it still appears upright.
If the new file would not be smaller than the original, the tool keeps the original file unchanged, metadata included, and says so. The figure on each result shows the saving.
Limits
Pictures larger than 50 megapixels are scaled down to 50 megapixels before compression, because a browser cannot work reliably on larger canvases. An animated GIF or WebP is compressed as one still picture, its first frame.
Example: a phone photo for a website
You have a 4000 × 3000 pixel photo from your phone, a JPEG of several megabytes. Set Maximum width to 1600 and keep the quality at 80. The picture is scaled to 1600 × 1200 pixels, which is plenty for a web page, and written again as a new file. The result shows how much smaller it is than the original.
The original on your phone stays as it was: the tool only creates a new file for you to download.
Frequently asked questions
Are my pictures uploaded to a server?
No. Your browser decodes, scales and encodes each picture on your own device. You can check this by turning off your internet connection after the page has loaded and compressing an image.
Why is a compressed file sometimes the same size as the original?
If the re-encoded file would not be smaller, the tool keeps the original, so no file ever grows. A JPEG that is already well compressed often gives this result at a high quality.
Which quality should I choose?
For photographs, 75 to 85 keeps most of the detail at a much smaller size. For screenshots and graphics with flat colours, PNG or WebP at a high quality usually looks better than JPEG.
Does compression remove the location and camera details?
Yes, when a file is re-encoded. The copy is written from its pixels only, so the camera, date and GPS information are not carried over. A file that is kept unchanged keeps its metadata.
Why is AVIF missing from the list?
AVIF is offered only where your browser can write it. Many browsers can open AVIF pictures but cannot save them yet, so the option appears only when it works on your device.
Can I compress several pictures at once?
Yes. Add up to 50 files, run the compression once, and download them all as one ZIP file. Each picture is compressed separately and gets its own result.
Sources
- WebP: Google's guide to the WebP image format
- ITU-T T.81: the JPEG standard
- AV1 Image File Format (AVIF) specification
- HTMLCanvasElement.toBlob(): how the browser writes an image
Figures and text last checked on Tuesday, November 10, 2026.