Compress Images Online
Compress images online for free: JPG, PNG, WebP and iPhone HEIC, one or dozens at once. See the real size and a before/after preview. Nothing is uploaded.
- Free, no sign-up
- Files stay on your device
- No watermark
By using this tool you agree to our Terms and Privacy Policy.
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How to compress images
Upload one or many images: JPG, PNG, WebP, GIF, BMP or iPhone HEIC.
Pick Extreme, Recommended, Light or a target size in KB, and check the before/after preview.
Download each image or all of them as a ZIP. Nothing leaves your device.
An image compressor that shows you the result first
Real sizes, not guesses
Every compression level shows the exact size it produces on your own image, and a draggable before/after slider (with a 100% zoom on the centre) lets you check the quality before you download.
Smart PNG compression
PNGs are reduced to an optimised colour palette with dithering, like dedicated lossy PNG tools, so they usually get much smaller while keeping transparency.
Target size and resizing
Need every photo under 200 KB for a form or a website? Set a target size per image, choose a maximum width or height, or convert to WebP, JPG or PNG.
Never bigger, never uploaded
If an image is already well optimised, the original is kept instead of a larger copy. All the work happens in your browser: no upload, no sign-up, no watermark.
Compress images without guessing
Picking a compression level blind means guessing how big the file will be. BestConverter measures the result on your own image first: each level shows the exact file size it produces, and a draggable before/after slider with a 100% zoom on the centre lets you compare details before you download. Add one image or dozens at once, choose a level once, and every file is compressed with the same settings. With several images you can switch the preview between them before you start.
How each format is compressed
- JPG photos are re-encoded at a tuned quality. Large phone and camera photos usually get much smaller with no visible change.
- PNG images are converted to an optimised palette of up to 256 colours with Floyd-Steinberg dithering and saved as an indexed PNG. Transparency is kept, and images with few colours stay pixel-perfect.
- WebP is usually the smallest choice for websites, and you can convert any image to it. If your browser cannot save WebP, the option is disabled.
- HEIC photos from iPhones are converted to widely supported JPG. BMP files are saved as JPG, and still GIFs as PNG.
Hit a size limit exactly
Job portals, government forms and online shops often reject images over 100 KB, 200 KB or 1 MB. Choose Target size, enter the limit, and each image gets the highest quality that fits. If quality alone is not enough, the dimensions are reduced step by step until it fits. You can also set a maximum width or height, for example 1920 px for Full HD, which saves the most space on large photos. Images are never enlarged.
Honest results
Re-encoding can make an already optimised file larger. With Never make a file bigger turned on (the default), BestConverter keeps the original in that case and tells you so. Animated GIFs are kept unchanged instead of losing their animation. Re-encoded images lose their EXIF metadata, including GPS location. The final screen lists the savings for every file, and you can download them one by one or all together as a ZIP. Files that cannot be read are skipped and listed at the end.
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Frequently asked questions
How do I compress an image to under 100 KB?
Upload the image, choose Target size and type 100 in the KB box. BestConverter finds the highest quality that fits, and if quality alone is not enough it reduces the dimensions step by step. If a limit cannot be reached, you get the smallest version possible and a note telling you so.
How much smaller will my images get?
It depends on the image. Large photos straight from a phone or camera usually shrink the most with the Recommended level and no visible difference, while images already compressed for the web may shrink only a little. Extreme saves the most with some visible loss, and Light keeps the most detail. The options window measures every level on your image before you start.
Can I compress PNG images without losing transparency?
Yes. PNG output keeps transparent and semi-transparent areas. PNGs are compressed by reducing them to an optimised palette of up to 256 colours with dithering, and logos, icons and screenshots with few colours are kept pixel-perfect. Only JPG cannot store transparency, so transparent areas turn white if you choose JPG.
Can I compress iPhone HEIC photos?
Yes. HEIC and HEIF photos are decoded in your browser and saved as JPG (or the format you choose), which every app and website can open. HEIC is already a very efficient format, so the JPG can be about the same size or larger unless you also pick a Resize option.
Does compressing an image remove EXIF data and GPS location?
Yes, for every image that is re-encoded. Camera model, date taken and GPS location are removed, which is good for privacy, and photos are rotated upright first. If an image is kept as the original because compression would not help, its metadata is unchanged.
Is it safe to compress images online here?
Yes. Compression runs entirely in your browser, so your images never leave your device and there is no daily limit. The only limit is your device memory: very large images (tens of megapixels) may need the Resize option on phones.