Why HEIC files won't open everywhere
Since iOS 11, iPhones and iPads have saved photos in HEIC (High Efficiency Image Container) by default. The format stores images at roughly half the file size of an equivalent JPG, which is why Apple adopted it — but support outside the Apple ecosystem is patchy. Windows can't preview HEIC without an extra codec extension, many older photo editors don't recognize it, and upload forms on job sites, government portals, and marketplaces often reject it outright. Converting to JPG, a format every device and website has handled for decades, is the fastest way around all of that.
How this converter works
When you drop a HEIC file in, a WebAssembly decoder running inside a Web Worker reads the file and re-encodes it as a JPG, entirely on your own computer. The Web Worker keeps the heavy decoding off the page's main thread, so the interface stays responsive while a batch churns. Queue as many photos as you like; three convert in parallel, and each one shows its status as it moves from pending to done. Afterwards, save files one at a time or take the whole set as a single ZIP.
Why local conversion matters for photos
Photos deserve more caution than most files. A HEIC straight off an iPhone can carry GPS coordinates, capture times, and device details in its metadata, and the picture itself might show faces, documents, or the inside of your home. Because this converter does all its work in the browser, none of that is transmitted anywhere — open your browser's network panel while converting and you'll see no upload request. There is no server-side copy to be stored, scanned, or leaked.