HEIC is the format an iPhone uses by default, and it is the reason photos that look fine on the phone refuse to open on Windows, in older photo software, or on most websites you try to upload them to. This converter decodes HEIC and HEIF images with the heic-to library, a WebAssembly build of the libheif decoder, and writes out ordinary JPG files that open anywhere.
Apple adopted HEIC because it stores the same picture in roughly half the space of a JPEG. That efficiency is exactly what makes it awkward to share: the format depends on the HEVC video codec, whose patent licensing has kept it out of most browsers and out of Windows without a paid extension. Converting to JPG trades a little file size for the ability to actually use the photo.
The HEIC decoder runs as WebAssembly inside your browser. Your camera roll is never uploaded, and the GPS coordinates many iPhone photos carry are dropped during conversion rather than transmitted somewhere.
.heic and .heif extensions are accepted, and you can select a whole batch at once.Conversion runs in two stages. First the HEIC file is decoded to a full-quality intermediate JPEG at quality 0.92, which is what the decoder produces. That image is then encoded again at the quality you selected — 0.92 for High, 0.85 for Normal — using MozJPEG where the browser supports WebAssembly workers.
Choosing High therefore gives you the closest possible match to the original: both stages sit at 0.92, well above the threshold where JPEG artefacts become noticeable on photographic content. Expect the resulting file to be roughly one and a half to two times the size of the HEIC, which is simply the cost of the older, less efficient codec.
A HEIC file exported from an iPhone contains the still image, which is what gets converted. The short video component of a Live Photo is stored as a separate .mov file alongside it and is not part of the HEIC, so it is unaffected. Burst sequences export as individual HEIC files and convert individually.
HEIC uses the HEVC codec, which Windows does not decode without a paid extension from the Microsoft Store, and which most browsers do not support at all because of its patent licensing. Converting to JPG sidesteps the whole problem.
Very slightly, and only in ways that are difficult to see. The HEIC is decoded to an intermediate JPEG at quality 0.92 and then encoded at your chosen quality. Selecting High keeps both stages at 0.92, which is above the level where compression artefacts are visible on photos.
Usually yes, roughly one and a half to two times. HEIC compresses far more efficiently than JPEG; that efficiency is what you give up in exchange for a file every device can open.
No. The conversion redraws the image and writes a fresh JPEG, so EXIF metadata including GPS coordinates, camera model and timestamps is not carried over.
Yes. Add as many as you like; they are decoded one after another and the results are packed into a single ZIP. Very large batches are limited only by your device’s memory.
No. The libheif decoder is downloaded once as WebAssembly and then runs entirely in your browser. The photos themselves are never transmitted.