HEIC decoder used by ImageBench ImageBench opens HEIC photos in your browser with libheif-js 1.23.5, an Emscripten build of libheif 1.23.5 with the libde265 1.0.15 HEVC decoder. It is loaded only when you open a HEIC file, and it runs entirely on your device. The decoder is two plain files served unchanged from this site: /vendor/libheif/libheif.js /vendor/libheif/libheif.wasm They are the files libheif-js ships in libheif-wasm/, byte for byte. You can replace them with your own build of the same library: the site loads them as separate files and does not bundle or modify them. Licences libheif and libde265 are licensed under the GNU Lesser General Public License, version 3 (/licenses/LGPL-3.0.txt), which builds on the GNU General Public License, version 3 (/licenses/GPL-3.0.txt). The libheif licence file, with its MIT-licensed parts, is /licenses/libheif-LICENSE.txt. libheif-js is licensed under the LGPL-3.0. Source code libheif-js 1.23.5 (the build scripts and wrapper): https://github.com/catdad-experiments/libheif-js libheif: https://github.com/strukturag/libheif libde265: https://github.com/strukturag/libde265 If you want the corresponding source for the exact files above and the links do not work, ask me through https://appsbyluke.com/#contact and I will send it.