You take a photo on your iPhone, transfer it to your Windows PC, and it will not open. Or you try to upload it to a website and get an unsupported format error. The file ends in .heic. This is normal, it is fixable in seconds, and you do not need to install anything sketchy to do it.
What HEIC is, and why Apple uses it
HEIC (High Efficiency Image Container) is the format iPhones have used by default since iOS 11. It is based on the HEVC video codec and stores the same quality as JPG at roughly half the file size, plus extras like Live Photos and depth data. The trade-off is compatibility: Apple devices handle it natively, but Windows, many web uploaders, and older software do not. JPG is the format everything accepts.
Option 1: stop shooting in HEIC
If you would rather never deal with this again, change the setting once. On your iPhone, go to Settings, then Camera, then Formats, and choose Most Compatible. New photos will save as JPG. Your existing photos stay HEIC, so you will still need to convert the ones you already have.
Option 2: convert on your device
On a Mac, open the photo in Preview, choose File, then Export, and pick JPEG as the format. On Windows 10 or 11, the Photos app can open HEIC files if the HEIF Image Extensions from the Microsoft Store are installed, and then you can save a copy as JPG. Both work fine for one or two photos, but they get tedious for a whole album.
Option 3: convert in the browser, without uploading
The fastest option for a batch of photos is a converter that runs entirely in your browser. Your photos are decoded locally and never sent to a server, which matters: family photos are not something to hand to a random conversion site. Drop the .heic files in, pick JPG, PNG, or WebP as the target, and download the results.
One practical tip: converting HEIC to JPG and then re-saving that JPG again and again degrades quality, because JPG is lossy. Convert once, keep the original HEIC as your archive copy, and use the JPG for sharing or uploading. For a whole album, convert in one batch rather than file by file, and keep the filenames identical apart from the extension — that way the converted set stays in the same order as the originals and nothing gets lost.
After converting, shrink the file
A JPG straight out of a modern iPhone is often 3–6 MB — too big for email attachments and slow on web pages. After converting, compressing it to a sensible quality and size usually cuts the file by 60–80% with no visible difference. That is a separate step from converting, and it is worth doing for anything you publish or send.
Try it
Drop your photos into the HEIC Converter to convert them to JPG, PNG, or WebP locally in your browser. Then run the results through the Image Compressor to shrink them for sharing. One more thing worth doing before you share any photo: read How to Remove EXIF Data from Photos Before Sharing — HEIC files carry location data, and converting does not remove it.