Every person who has ever plugged an iPhone into a Windows PC knows the moment: you open the camera roll folder, double-click a photo you just took, and you get either a grey thumbnail or an error that reads something like "this file format is not supported." The photos are fine. The camera is fine. The problem is a four-letter format called HEIC that nobody warned you about.
I've spent the better part of two years helping friends, relatives, and students get their iPhone pictures onto school websites, job-application portals, and old laptops. In this guide I'll explain what HEIC is, why it exists, why it breaks so many workflows, and — most importantly — the exact steps to convert it to JPG on Windows, Mac, and iPhone itself, without paying for an app or trusting a sketchy website with your photos.
What is HEIC, anyway?
HEIC stands for High Efficiency Image Container. It's the file extension for images saved in the HEIF format (High Efficiency Image File Format), which is based on the same compression technology as the HEVC video codec. Apple switched the default iPhone camera to HEIC starting with iOS 11 in 2017, and almost every iPhone made after that date shoots in this format by default.
The trade-off is simple. At the same subjective visual quality, a HEIC photo takes roughly half the file size of an equivalent JPEG. A 12-megapixel iPhone shot that lands at 3.5 MB as a JPEG often comes out around 1.5–2 MB as HEIC. On a 128 GB phone that stores thousands of photos, that difference is real storage you don't have to buy extra iCloud space for.
The catch is compatibility. HEIC is brilliant inside Apple's walled garden — Photos on macOS, iOS, and iPadOS open it natively. The moment you leave that ecosystem, the format falls apart.
Why your iPhone photos won't open on Windows
Windows does not ship with a HEIC decoder built in. Until you install one, the operating system has no idea how to read the compression inside a .heic file. You'll see the symptoms in three common places:
- File Explorer thumbnails are black or blank. Windows cannot generate a preview, so you see a generic icon instead of the picture.
- The Photos app says "This file isn't supported" or "It looks like we don't support this file format."
- Web upload forms reject the file. When you try to upload a homework photo to a university portal or a resume headshot to a hiring site, the form throws "unsupported file type" and only lists
.jpg,.jpeg, and.png.
None of this means your photo is corrupt. It means the receiving software lacks the codec. The fix is either to install a decoder on the machine that needs to view the file, or to convert the photo to JPG once and for all.
Three reliable ways to convert HEIC to JPG
After testing every approach I could find, there are three paths that actually hold up. Here's how they compare.
Method 1: In-browser conversion (fastest, most private)
This is the route I recommend for most people. You drag your .heic files into a converter that runs entirely in your browser — the decoding happens with a WebAssembly build of libheif on your own machine, and nothing is uploaded to a server. Our own HEIC to JPG converter works this way: drop in one photo or fifty, pick JPG (or PNG/WebP), and download each result individually or as a single ZIP. Because the files never leave your device, it's safe for anything sensitive — a photo of a signed lease, a passport scan, client work.
Method 2: Install the Windows HEVC extension (keeps HEIC as-is)
If you mostly just want to view your photos on a Windows machine without converting anything, install the HEIF and HEVC extensions from the Microsoft Store. After that, the built-in Photos app and File Explorer thumbnails finally render HEIC natively. The downside: you still have a HEIC file that will be rejected by most websites, and the HEVC Video Extensions are sometimes listed as paid (around $0.99) even though free copies exist via the device-manufacturer version. This fixes viewing, not uploading.
Method 3: Convert during transfer (Apple's built-in path)
On a Mac, HEIC opens everywhere already, so conversion is trivial: select photos in Preview or Photos, use File → Export, and choose JPEG. On Windows, if you plug the iPhone in via USB and use the "Import" wizard in the Photos app, newer Windows versions can transcode to JPEG on import — but this is finicky and often fails without the extensions installed.
| Method | Best for | Uploads files? | Batch? | Cost |
|---|---|---|---|---|
| Browser converter (WASM) | One-off uploads, sensitive photos | No — stays on device | Yes, ZIP output | Free |
| Windows HEVC extension | Just viewing on PC | No | n/a (no conversion) | Free–$0.99 |
| Mac Preview export | Mac owners, small batches | No | Select-all, works | Free |
| Cloud converter websites | Nothing — avoid for sensitive files | Yes, uploaded to server | Often capped | Free with limits |
How to make your iPhone shoot JPG by default
If you're tired of this problem recurring every time you take a photo, the cleanest fix is to stop producing HEIC in the first place. On your iPhone, open Settings → Camera → Formats. You'll see two options:
- High Efficiency — the default, which saves HEIC. Best for saving space.
- Most Compatible — forces the camera to save standard JPEG files. Best if you constantly transfer photos to Windows or upload them to websites.
Tap Most Compatible. From now on every new photo is a JPEG that opens anywhere. The trade-off is file size: expect roughly double the storage per photo. For most people with 256 GB phones, that's a worthwhile price for never hitting "unsupported file" again.
One more setting worth knowing: in Settings → Photos, scroll to the bottom and find Transfer to Mac or PC. Set it to Automatic so that when you cable-transfer photos, iOS converts them to JPEG on the fly. Leave it on "Keep Originals" only if you know you need the raw HEIC.
Batch converting and common pitfalls
Converting one photo is easy. Converting 200 from a family vacation folder is where people get stuck. A few lessons I've learned:
- Always batch with a ZIP output. Downloading 200 individual JPEGs by hand is how you accidentally skip files. A browser tool that bundles results into one archive is the sane way.
- Preserve metadata if it matters. JPEG keeps the date and GPS info, but a few conversion paths strip EXIF. If you're organizing a photo library, check the output dates before you overwrite originals.
- Don't re-compress repeatedly. Every JPEG re-encode throws away a little more quality. Convert HEIC → JPG once, at quality around 90%, and stop. If you then need a smaller file for the web, that's a separate resize step, not a second HEIC conversion.
- HEIC live photos are two files. A Live Photo is a still image plus a short video. Converting the
.heiconly gives you the frame; the video part stays behind.
When you need to go the other direction — or convert between JPG, PNG, and WebP for web use — our image format converter handles those three directions in the same local-browser way, including filling transparent backgrounds when you flatten a PNG onto a JPEG.
Need to convert your iPhone photos right now? Drop your HEIC files into the converter — no upload, no sign-up.
Open the HEIC to JPG converterFrequently asked questions
Does converting HEIC to JPG reduce image quality?
It's a re-encode, but at JPEG quality 90% the difference is invisible on screen and in print for most photos. HEIC itself is already compressed, so you're not starting from a "raw" file. The main loss is in fine detail at 100% zoom and any transparency, which JPEG doesn't support. If you need pixel-perfect output, choose PNG instead.
Can I convert HEIC files without installing anything?
Yes. A browser-based converter uses a local WebAssembly decoder, so there's nothing to install and the files never leave your device. You can even turn off your internet connection after the page loads and it still works. This is the fastest option if you're on a work PC where you can't install software.
Why do my converted JPEGs look larger than the originals?
Because HEIC is roughly twice as efficient as JPEG at the same quality. A 1.8 MB HEIC typically becomes a 3–4 MB JPEG. That's expected, not a bug. If file size matters after conversion, resize the image or re-save at a lower quality — but for uploading to a website or email, the JPEG size is normal.
Should I just switch my iPhone to JPEG forever?
If you regularly move photos to Windows, upload them to forms, or send them to people on Android, yes — set "Most Compatible" in Camera settings. If you live entirely inside Apple devices and care about storage, keep HEIC and convert only when you need to share a specific photo.
Are my photos safe when I use an online converter?
Only if the converter runs locally. Many "free online" converters upload your photos to their servers, process them, and keep a copy — which is a real privacy risk for anything personal. A browser-based tool that uses WASM keeps every byte on your machine, so it's safe to test by going offline.
