Real HEIC decoding in your browser
CollagePlus includes a pinned libheif WebAssembly decoder instead of relying on inconsistent native browser support. Conversion runs in a module Worker where supported, keeping the interface responsive during batches.
No uploads or hidden cloud conversion
The original HEIC bytes, decoded pixels and JPG/PNG results remain on your device. Temporary output URLs are released when files are removed or the page is closed.
JPG or PNG?
JPG is smaller and works almost everywhere. PNG is lossless and may be much larger. Transparent HEIC pixels are flattened onto white only when JPG is selected.
Bursts and multi-image containers
A HEIC container can hold several images. This focused converter exports the primary first image and labels results when additional images are present.