Frequently asked questions about compressing images
Are my images uploaded?
No. The shrinking happens in your own browser, using the drawing functions your device has for that. No file is sent to us or to anyone else, so we do not see your images either.
Which format should I choose?
WebP for almost everything: every browser from the last few years displays it, and it weighs clearly less than JPEG at the same quality. Choose JPEG when an old system needs to be able to open the file. Keep PNG for images with sharp edges or transparent parts, such as a logo.
Why can I not create AVIF?
No browser can write AVIF today, only display it. If this compressor offered AVIF, it would silently give you something else back. WebP achieves most of the same gain in practice.
What quality should I set?
Around 80, you usually see no change from the original in a photo, while the file becomes much smaller. Go lower for images that appear small on the page, and higher for a photo you show at full width.
Why does my file sometimes get bigger?
Because it was already well optimized. Converting it again at a high quality then adds more than it removes. The list says so too: in that case, just keep your original.
What does the maximum width do?
It shrinks images wider than the chosen value and leaves narrower ones untouched. That is usually the biggest gain: a photo 4000 pixels wide in a box of 800 pixels sends five times more image than can be seen.
Can I shrink an SVG?
Not here. An SVG consists of drawing instructions instead of pixels; you make those smaller by cleaning up the drawing itself, not by re-encoding it.
How do I know which images on my site are too heavy?
That is what the image scan is for. It goes through your pages, measures each file separately and tells you which are too heavy, which are in an outdated format and which are delivered larger than they are shown.
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