AVIF is excellent and awkward
AVIF produces the smallest files of any format a browser will display — often 30–50% below WebP at matching quality. The problem has never been the format; it is everything that is not a browser.
JPG is the format that opens in absolutely everything, which is the whole reason to leave AVIF. Transparency is filled with white, because JPG has no alpha channel.
Where the friction actually appears
- Desktop photo editors, many of which still cannot open it
- Marketplace and job-board uploaders that validate file types
- Print services and document templates
- Anything running on an operating system a few years old
Nothing leaves your machine
The decoding and re-encoding both happen in this tab using your browser's own image support. That also explains the one failure mode: if your browser cannot decode AVIF, there is no server to fall back to. AVIF decodes in Chrome 85+, Firefox 93+ and Safari 16+. If your browser is older than that, this page cannot read the file — nothing is uploaded, so there is no server-side fallback.
Questions
Why convert away from AVIF at all?+
Because AVIF is the newest of the mainstream formats and support outside browsers is thin. Photo editors, office software, marketplace uploaders and print services frequently reject it. The file is excellent and nothing can open it, which is not a useful combination.
Will the file get bigger?+
Yes, usually noticeably. AVIF is the most efficient of these formats, so moving to JPG costs size. That is the trade you are making for compatibility.
My browser says it cannot read the file.+
AVIF decodes in Chrome 85+, Firefox 93+ and Safari 16+. If your browser is older than that, this page cannot read the file — nothing is uploaded, so there is no server-side fallback.