Image Compressor
Frequently Asked Questions
Everything you need to know about image compression
Is the compression lossless or lossy?
For JPEG and WebP the compression is lossy (with quality loss), controlled by the quality slider. For PNG the quality does not affect sharpness but file compression. For maximum quality use 90-100%, for smaller files lower to 60-80%.
Where are my images uploaded?
Images are NOT uploaded to any server. All compression happens directly in your browser via the HTML Canvas API. Your files remain private on your device.
Which format to choose for the web?
WebP offers the best modern compression (30-50% smaller than JPEG at the same quality). JPEG is ideal for photos. PNG is preferable for images with transparency or graphics with text. For maximum compatibility use JPEG.
Does compression lose quality?
On JPEG and WebP yes, and the quality slider decides how much: between 90 and 100 the loss is invisible, between 60 and 80 the file gets far lighter. On PNG what changes is compression, not sharpness.
Are the images uploaded to a server?
No, the compression happens inside the browser on an HTML canvas, so the files stay on the device. It can be used on confidential images without them going anywhere.
Which format is best for the web?
WebP is the most efficient and at the same quality weighs 30 to 50 per cent less than JPEG. JPEG stays the safe choice for photographs, and PNG is what you need when transparency matters.