LocalPixWebP and AVIF are reasonable originals on the web. They are a poor attachment when the next system only understands JPEG: a legacy CMS, a mail client that shows a broken icon, or an application portal whose accept list is .jpg / .png. Convert at the moment you need compatibility. Keep the modern file if you are only publishing on a site that already serves it.
LocalPix does not encode WebP or AVIF in this MVP, and it does not turn JPG back into those formats. The tools are one way: WebP to JPG and AVIF to JPG, using the browser’s decoder and a local canvas JPEG.
Convert when
- The CMS or form rejected the upload and named the type (not the pixel size).
- A recipient on desktop mail cannot open the image, and sending a screenshot of it would be larger and worse.
- You exported AVIF or WebP from a design tool and the print or email step wants JPEG.
Stay on WebP or AVIF when
- You are optimizing a page you control and the audience’s browsers already decode it.
- You need animation. These tools are for stills. An animated WebP is the wrong input.
- You need transparency. JPEG has no alpha. A transparent WebP becomes a flat image once it is JPEG. For a cutout, use Remove background and keep the PNG (product photo guide).
Steps
- Open WebP to JPG or AVIF to JPG. Proof, if you want it: Verify local and How to self-prove 0-byte upload.
- Drop the still. If your browser cannot decode AVIF, the page shows an error and stops. Try a current desktop browser — there is no server fallback that would upload the file.
- Download the JPG from the local
blob:URL. - If that JPG is over a KB cap, continue with Compress to KB (100 / 200 / 500 KB).
Pitfalls
- Decode support differs. WebP is widely decoded. AVIF still fails in some older browsers. The failure is local and visible.
- A second generation. WebP/AVIF → JPEG is lossy. Do not convert again unless the format is the reason the file was rejected.
- HEIC is not WebP. iPhone camera files use HEIC to JPG.
FAQ
Does the image leave the device?
No. Decode and JPEG encode stay in the tab. No photo upload to LocalPix.
Can I convert JPG to WebP or AVIF here?
No. Only WebP → JPG and AVIF → JPG are in this MVP.
AVIF failed immediately. Was it uploaded?
No. If the browser cannot decode AVIF you get an error on AVIF to JPG. The file was not sent away to be decoded.
Related
WebP to JPG · AVIF to JPG · Compress to KB · Attachment KB caps · Verify local