Why iPhones take HEIC photos
Since iOS 11, iPhones store photos as HEIC by default: the HEIF container format holding an image compressed with HEVC, the same family of codec as modern video. Apple chose it because it keeps photos smaller than JPEG at comparable quality, which adds up quickly on a phone that shoots every day. The format is a good one — the problem is everywhere around it.
HEVC is patent-encumbered, so support is not free for other software to include. macOS and modern Android handle HEIC natively; Windows needs image extensions from its Store, with the HEVC piece historically sold rather than given away. Most websites and forms accept only JPEG, PNG, WebP or GIF, and reject .heic uploads outright. A photo that opens fine on the phone that took it can be unusable two metres away — that gap is what this tool closes.
What a conversion actually does
HEIC and JPG are both compressed formats, so this is a decode-and-re-encode, not a rename. The decoder turns the HEVC data into full pixel data, and the browser’s encoder writes it back out as a JPG at your chosen quality — the same canvas API every other tool on this site uses. One re-encode at high quality keeps what a screen can show; only repeated re-encoding at low quality visibly degrades a photo.
If a website accepts PNG but not JPG transparency loss matters to you, the PNG option writes the decoded pixels without JPEG compression. Note that HEIC photos from a camera are already opaque, so JPG is the usual choice — PNG mostly serves screenshots and graphics.
Should I just switch my iPhone to JPEG?
For photos you will keep sending to websites and Windows machines, that is a reasonable setting: Camera → Formats → Most Compatible makes the camera write JPG directly, at the cost of larger files. What the setting cannot do is convert the photos you already have. A library shot in HEIC stays HEIC, and exporting from the Photos app one by one is slow. That is the moment for a converter: drop the batch, download the JPGs, done.
Why nothing is uploaded
Photos are among the most personal files there are — faces, homes, children, documents. Free online converters that process HEIC in the cloud ask you to hand exactly that to a server you know nothing about, on the strength of a deletion promise you cannot verify. Here the decoding happens inside the page itself, the JPG is written by your own browser, and the proof is one network tab away: no request carries your photo. The broader case is in why upload-based tools are a privacy problem.
Questions
Is my photo uploaded anywhere?
No. The decoding runs inside your browser itself, next to the encoder that writes the JPG. Nothing about your photo is transmitted, and no request you watch in the network tab carries it.
Does converting HEIC to JPG lose quality?
The pixels are decoded fully, then re-encoded once at the quality you choose. At the default 90% the result is visually close to the original; choose PNG if you need the decoded pixels without any JPEG re-encoding.
Windows wants me to install or buy an extension to open HEIC. Do I need it here?
No. This page does not use the image codecs installed on your computer. The decoding happens inside the browser itself, so it works the same on Windows, Android and Linux, where HEIC support is missing or paid.
Why do my photos arrive as HEIC when I copy them to my computer?
A USB copy transfers the files exactly as the phone stores them, and the phone stores HEIC. On the iPhone, Settings → Apps → Photos → Transfer to Mac or PC → Automatic (Settings → Photos on older iOS) makes the phone convert photos as it transfers them, which fixes future copies. It does nothing for files already on the computer — that is the moment for this converter. The separate Camera → Formats → Most Compatible setting is what makes the camera shoot JPG in the first place.
Can I convert several photos at once?
Yes, up to 30 per batch. Drag a whole selection in, then use Download all. Each HEIC becomes one JPG named after the original file.