Quality versus target size
Quality mode gives you direct control over JPG and WebP encoding. Target mode searches a limited set of quality values and chooses the highest one that fits your KB limit.
Private image compressor
Compress images online—
privately.
Reduce JPG, PNG, and WebP file sizes directly in your browser. Choose a quality level or target size in KB, inspect the result, and download it without uploading your image.
✓ Quality or target-KB mode✓ Original and compressed preview✓ Image stays on your device
01
Private · on-deviceAdd an image
JPG, PNG, or WebP up to 20 MB. One image at a time.
Add an image to choose compression settings.
3 formatsJPG, PNG, WebP
2 modesQuality or target size
On-deviceNo image upload
1 downloadCorrect format and size
Private by architecture
How private image compression works.
ResizeKit uses the image decoder and canvas encoder already built into your browser. Your file is read from your device, processed in local memory, and downloaded from a temporary local URL.
Nothing degrades twice
Every settings change starts from the original decoded source, never from the last compressed result. That prevents repeated quality loss while you experiment.
Dimensions stay under your control
ResizeKit does not silently shrink width or height. Target mode changes dimensions only when you turn that option on, and the result shows the exact final size.
Choose the right output
JPG, PNG, or WebP?
File size depends on the image itself, not just the extension. These practical differences help you choose an honest output.
Photos and broad compatibility
Adjustable lossy quality and no transparency. Transparent pixels use the background color shown in the tool.
Lossless pixels and transparency
No browser quality slider. A significantly smaller target may require reduced dimensions or a different format.
Small files with transparency
Adjustable quality, modern browser support, and transparency make WebP a strong choice when file size matters.
When the number is strict
What if the target cannot be reached?
ResizeKit first tries quality reduction at the original dimensions. If the smallest practical result remains above the target, it says so plainly and offers two honest choices: allow a proportional dimension reduction or switch to a more efficient format such as WebP.
A target result is labeled reached only when the generated bytes are actually at or below the requested limit.
Compression questions
Know what happens to your image.
No. ResizeKit decodes, compresses, previews, and prepares the download inside your browser. Image bytes are not sent to ResizeKit or a third-party compression service.
Make the file fit
Compress an image →A smaller image is one local compression away.
No account, upload, or watermark.