Image Compression
Compress PNG/JPG images
Features
Keep the PNG/JPG format
Compress while keeping the original image format and preserving transparency
Adjust quality with slider
Adjust from 10–100%. PNG at 100% compresses while preserving quality
Batch process multiple images
Upload multiple files together and compress them at the same time
Compare size before and after
Display the size before and after compression and the reduction rate for each image
How to use
Select image files
Choose PNG and JPG images from the upload field and add multiple at once
Adjusting quality
Move the slider between 10% and 100%; changes are applied to all images instantly
Check the size reduction rate
Check each image's size before and after compression and the reduction rate in the preview
Download the compressed images
Save them one by one, or save them all at once as a ZIP with "Download all"
Use cases
Speeding up web pages
Reduce image size to improve display speed and page loading
Lightening email attachments
Shrink attachments with size limits to a sendable size
Saving storage
Reduce device and cloud storage usage to keep more images
For SNS and blog posts
Optimize size while keeping image quality to match the limits of posting sites
Basic Knowledge
Difference Between Lossless and Lossy Compression
PNG is a lossless compression format that preserves image quality, while JPG is a lossy compression format that discards information imperceptible to the human eye to achieve significant size reduction. The same image may compress more effectively in different formats depending on content: PNG works better for illustrations and text, while JPG is more efficient for photographs.
Image Quality and File Size Trade-off
With JPG, even a slight reduction in quality settings can significantly decrease file size, but excessive reduction causes block-like noise artifacts. PNG compression works by reducing the number of colors used, so lowering quality settings may introduce banding in gradients. Finding the right balance typically involves comparing the visual appearance against file size to determine the optimal trade-off point.
Safety and Privacy
Runs entirely in your browser
Your input data is processed only within your browser and is never sent externally.
Processing only in your browser
compressing images is processed entirely within your browser, and input data is not sent to any server.
Communications encrypted with HTTPS
Page loading is also encrypted by TLS, and content cannot be read by third parties.
No transmission to third parties
Input content is not sent to external services such as ad networks or trackers.
No automatic saving of results
the compressed images and input suggestions are not stored on the server.
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Updates
- update #119
Add image quality explanation in image compressor and display preview larger
Changed the slider label to 'Image Quality' and now displays on screen that images that would become larger after compression will output the original file as-is.
- update #117
Image Compressor: PNG compression quality slider now applies
At 100% quality, compression preserves image fidelity. Below 99%, file size reduces according to quality level. Transparency is maintained.