Image Compressor: Reduce JPG, PNG and WebP File Size
Compress JPG, PNG and WebP images in your browser with a quality level or a target file size, compare before and after, and download them.
Drop images here or choose them
JPG, PNG and WebP. GIF (first frame), BMP and, where your browser can open it, AVIF are also accepted and saved as PNG, JPG or WebP.
Images
Larger images are scaled down to fit inside this box, keeping their aspect ratio. Smaller images are not enlarged. Leave a field empty to limit only the other side.
JPG, PNG and WebP images keep their format. GIF, BMP and AVIF images are saved as PNG, because browsers cannot save in those formats; choose JPG or WebP for smaller files from photos.
JPG does not support transparency: transparent areas become white.
Choose images or drop them on the box above.
Before and after:
"Actual size" shows both images at the pixel size of the compressed image, and the two views scroll together. Your browser may scale images on high-resolution screens.
Notes
- JPG and WebP compression is lossy: some detail is discarded, and a lower quality gives smaller files with more visible artefacts such as blocks, blur or colour fringes. Compressing the same image again loses more detail.
- PNG output is reduced to a limited number of colours (quantisation), which works well for screenshots, logos and graphics but can cause banding in photos and smooth gradients. At the setting 100 the colours are not reduced, but nearly transparent pixels can change colour slightly, and 16-bit PNGs are saved with 8 bits per channel.
- Images that are already compressed may not get smaller, or may even get larger. In that case the original file is selected for download.
- With a target file size, the result is the largest file the tool found at or below the target, so it is usually somewhat smaller than the target. Very small targets can only be reached by reducing the dimensions, or not at all.
- EXIF, GPS, colour profile and other metadata are removed. The orientation recorded by a camera is applied to the pixels, so photos come out upright. Images with a wide-gamut colour profile can look slightly different afterwards.
- For animated GIFs only the first frame is saved.
- Very large images (above about 50 megapixels or 50 MB) need a lot of memory and may fail on phones or in older browsers. A target file size takes longer, because each image is encoded several times.
- Images are processed in your browser and are not uploaded to LeedyBox.
How to use
- Drop JPG, PNG or WebP images on the box above, or choose them with the file button. GIF, BMP and, where your browser can open it, AVIF are also accepted.
- Choose "Quality" and set the slider (75 by default), or choose "Target file size" and enter the largest file size you want in KB.
- If the images are larger than you need, turn on "Also limit the width and height". Choose the output format: JPG or WebP usually give smaller files than PNG for photos.
- Press "Compress images", then use "Compare" and "Actual size" to check the result for blocks, blur or banding.
- Download the images one by one or, for two or more images, all together as a ZIP file. If a compressed file is not smaller than the original, the original is selected for download; you can change this for each image.
Frequently asked questions
Are my images uploaded to a server?
No. The images are compressed in your browser and are not uploaded to LeedyBox. The PNG libraries (UPNG.js and pako) and the JSZip library for the ZIP download are loaded from leedybox.com itself; your images are not sent anywhere.
What does the quality number mean?
It is an encoder setting from 1 to 100, not a percentage of the original file size. JPG and WebP are saved by your browser at this quality. For PNG it sets the largest number of colours, from 256 at 99 down to 16 at 1; at 100 the colours are not reduced.
How does the target file size work?
For JPG and WebP the tool tries qualities between 5 and 95 and keeps the highest one it finds that fits. For PNG it tries fewer and fewer colours. If that is not enough and reducing the dimensions is allowed, the width and height are reduced step by step, down to 10 % of the original, and the search is repeated. If the target still cannot be reached, you get the smallest result with a warning.
Why did an image not get smaller?
Images that are already well compressed and small graphics may not shrink, and saving a JPG photo as PNG often makes it larger. When the result is not smaller, the tool selects the original file for download. Compressing a JPG or WebP image again also loses more detail, so start from the original each time.
What happens to transparency and photo metadata?
PNG and WebP output keep transparency. JPG cannot store it, so transparent areas become white. EXIF, GPS, colour profile and other metadata are removed in every format; the orientation recorded by the camera is applied to the pixels first.