How f-auto picks a format
Every browser tells the server which image formats it can display. Simpanan reads that on each request and chooses:
- AVIF if the browser supports it. Usually the smallest for photos.
- WebP if the browser doesn't support AVIF but does support WebP.
- The original format for older browsers that support neither.
https://cdn.simpananawan.com/tr:w-800,f-auto/u/you/photo.jpgIt stays one link. You don't prepare several files or write a long <picture> element.
Why it matters
According to Google's own tests, lossy WebP images are on average 25 to 34 percent smaller than JPEGs of equivalent quality, and lossless WebP is about 26 percent smaller than PNG. AVIF is often smaller still for photos. Smaller files mean pages appear sooner, especially on mobile connections.
The exact saving differs for every image. The easiest way to find out is to try it in the demo on the homepage, which shows the original size next to the result.
Animated GIFs keep moving
Simpanan doesn't produce animated AVIF, so f-auto never turns a GIF or WebP into AVIF. Animated GIFs are delivered as they are so they keep playing, while still GIFs are converted to WebP like any other image.
Choosing a format yourself
If you need a specific format, put it in the link:
| Option | Result |
|---|---|
f-auto | AVIF, WebP or the original, depending on the browser. |
f-webp | Always WebP. |
f-avif | Always AVIF (if the server can't make AVIF, the original format is sent). |
f-jpg | JPG. Transparent areas get a white background. |
f-png | PNG, keeping transparency. |
Set quality with q- from 1 to 100 (default 80). PNG transparency is kept when converting to WebP or AVIF.
Safe for caches
Because one link can produce several formats, f-auto results are cached only in each visitor's own browser, never in shared caches like proxies or other CDNs. Every format is still kept in Simpanan's own cache, so it stays fast, and a visitor on an older browser never gets an AVIF by mistake.