When iPhone photos won't open on Windows โ convert without installing anything
What HEIC is and why it won't open
Since iOS 11, iPhones save photos as HEIC (HEIF): half the size of JPEG at the same quality. Great on the phone, but Windows Photos, older Photoshop versions, many upload forms and some chat apps can't read it or ask for a paid codec. This converter decodes HEIC inside your browser and writes JPG, PNG or WebP โ no file is uploaded.
HEIF is an ISO container format that applies the HEVC (H.265) video codec to still images; .heic is the extension Apple uses. The compression is excellent, but HEVC is covered by patents, so Windows ships without a built-in decoder and asks you to install extensions from the Store โ and the HEVC part is sometimes paid. On a work PC where you can't install anything, or when an upload form accepts only JPG and PNG, converting is the practical way out.
How to use it
- Click the dashed box on the first screen to choose HEIC files, or drag them onto it. Pasting a copied image with Ctrl+V works too, and you can select many files at once.
- On the work screen, pick the output format (JPG, PNG or WebP) and the quality (50โ100, default 90). The quality slider disappears for PNG because PNG is lossless.
- Files convert in the order you added them. Each card shows a preview and the original โ converted size. Change the format or quality and every card is re-converted with the new setting.
- Use Download on a card to save a single image, or Download all to save the converted files one after another. On phones and tablets that support file sharing, a Share / save button appears so you can send the results to your photo library or a messaging app directly.
- Use Add to bring in more files, or Clear to empty the list and go back to the start.
Choosing a format and quality
| JPG | The default, and the safest for sharing, uploading and printing. Quality 90 is indistinguishable from the original; dropping to around 80 saves space with hardly any visible change. |
|---|---|
| PNG | Lossless. Pick it if you need transparency or refuse to lose a single pixel of detail. Photos become much larger than the HEIC, so mind the file size. |
| WebP | Smaller than JPG at the same quality. The better choice for blogs, shops and anything published on the web; only very old software can't open it. |
- Drop in as many HEIC files as you like; they convert in order. Download each one as it finishes, or Download all at the end.
- JPG at quality 90 is visually identical and only slightly larger than the HEIC. Pick PNG if you need transparency, WebP for the web.
- Orientation (rotation) is applied automatically, and EXIF metadata such as GPS location is stripped in the process.
- File names are kept; only the extension changes to .jpg, .png or .webp.
How the conversion happens in your browser
The decoding is done by a WebAssembly build of the open-source libheif library running inside your browser tab. The decoder (about 1 MB) is downloaded once, on the first conversion; after that, no matter how many photos you add, nothing else is fetched. The decoded image goes through the browser's canvas and is re-encoded in the format you chose, and the resulting file is created entirely on your device. Our server never receives or stores your photos. That is why speed depends on your device rather than your connection, and why photos you would rather not hand to a third party โ work documents, pictures of your kids โ can be converted with peace of mind.
If you drop in a JPG, PNG or WebP instead of a HEIC, the decoder is skipped and the canvas simply re-encodes the image in the selected format โ handy for turning a PNG screenshot into a JPG, for example.
Shoot JPG in the first place
On the iPhone go to Settings โ Camera โ Formats โ Most Compatible to save JPG from now on. For photos you already have, use this converter, then shrink them with the image compressor if size matters. Live Photos convert to a still image only.
Frequently asked questions
Why is the first photo so much slower than the rest?
The first conversion includes downloading the decoder (about 1 MB). From the second photo on, only the conversion itself takes time.
Why do I see "Conversion failed"?
It appears when a file merely has a .heic extension but isn't really a HEIC, when the file was damaged in transfer, or when the format isn't supported. The card then reads "Not a HEIC or unsupported format". Export the photo again from the iPhone, or copy the original file over without any intermediate compression, and try again.
The converted file is larger than the original. Is that normal?
Yes โ HEIC compresses more efficiently than JPEG, so a JPG of the same picture is usually bigger. Lowering the quality slider brings the size down, and WebP is a good alternative if the image is going on the web.
Can I download everything as a ZIP?
Download all doesn't build a ZIP; it saves the converted files one by one. If your browser asks whether to allow multiple downloads, say yes. On a phone, the Share / save button is the more convenient way to save several photos to your library at once.
Does it work on Mac, Android or Linux?
It runs in the browser, so it behaves the same on Windows, macOS, Linux, Android and iPhone. There is nothing to install and no account to create.
Related tools
- Image Compressor & Converter โ resize and compress the converted JPGs if they are too large.
- EXIF Viewer & Remover โ check a JPG for leftover location and camera data before you share it.
- PDF Merge ยท Split ยท Image Converter โ bundle several converted photos into a single PDF.
- Photo Blur & Pixelate โ hide faces or license plates before posting.