You photograph a document on your iPhone, email it to yourself, open it on a Windows laptop — and nothing happens. The file is called IMG_4821.HEIC and Windows shrugs. Upload it to a job application portal and you get "unsupported file type." Send it to a friend on Android and they receive something they can't open.
The fix takes about ten seconds: convert the photo to JPG. This guide covers how to do that in bulk, for free, without handing your personal photos to a server you know nothing about — using the Quill Tools HEIC to JPG Converter.
Why Your iPhone Saves HEIC in the First Place
Since iOS 11, the default camera format has been HEIC — High Efficiency Image Container. Apple switched because HEIC files are roughly half the size of an equivalent JPEG at the same visual quality. On a 128 GB phone holding twenty thousand photos, that is not a small saving; it is thousands of extra pictures.
The catch is compatibility. HEIC compresses its picture data with HEVC (H.265), a codec that carries patent licensing obligations. That licensing is exactly why Windows doesn't ship HEIC support by default, why older photo editors reject the files, and why a great many upload forms have never heard of the format. Apple optimised for storage; the rest of the ecosystem never fully followed. If you want the longer background, we wrote a plain-English explainer on what a HEIC file actually is.
The Problem With Most Online HEIC Converters
Search "heic to jpg" and you get pages of converters. Nearly all of them work the same way: you upload your photo, their server converts it, you download the result. That means your picture — which might be a passport, a medical form, a photo of your children, or a whiteboard full of unreleased work — sits on infrastructure you have no visibility into, governed by a retention policy you didn't read.
Most of those services are probably fine. But there is no reason to take the bet, because the conversion doesn't require a server at all. Modern browsers can run libheif — the open-source HEIC decoder — compiled to WebAssembly, directly inside the page. The photo is decoded on your own hardware and re-encoded by your browser's own image encoder. Nothing is transmitted, so there is nothing to retain, leak, or log.
That is how the Quill Tools converter works, and it is why it has no file size cap, no daily limit, and no queue: there's no server capacity to ration.
How to Convert HEIC to JPG in Your Browser
- Open the HEIC to JPG Converter.
- Drag in your photos, or click to browse. Select as many as you like — a whole holiday album is fine.
- Choose JPG or PNG as the output format.
- If you picked JPG, set the quality. 90% is the sweet spot for photographs.
- Click Convert. Each photo is decoded and re-encoded on your device, with progress shown as it goes.
- Download images one at a time, or grab the whole batch as a single ZIP.
Because the decoder runs in a background worker thread, the page stays responsive while a large batch works through — and conversion speed depends on your processor rather than your upload bandwidth. A 4 MB photo that would take thirty seconds to upload on a weak connection converts in about a second locally.
JPG or PNG? A Short Answer
Pick JPG. It is what every upload form, email client, printing service, and photo frame expects, and its compression is designed for exactly the kind of continuous-tone content a camera produces.
Pick PNG only when you specifically need a lossless copy — for example, if the photo is going straight into an editor for heavy retouching and you want zero generational loss. Be ready for the file size: PNG uses lossless compression that works brilliantly for flat graphics and screenshots but poorly for photographic noise, so a 2 MB HEIC can easily become a 15 MB PNG.
On quality: converting HEIC to JPG does not "degrade" your photo in any way you will notice. The HEIC is decoded to full-resolution pixels first, then re-encoded. At 90% JPEG quality the difference is invisible at any normal viewing size. Drop to 60% and you will start to see softness in fine detail and gradients — useful when you deliberately want a small file, undesirable when you don't.
What Happens to Live Photos
A Live Photo is a HEIC still frame plus a short MOV video stored alongside it. Converting gives you the full-resolution still image — the motion clip is a separate file and isn't part of the conversion. That is almost always what you want; if you specifically need the movement, share the Live Photo from the Photos app as a video instead.
The Other Fix: Stop Making HEICs
If you convert photos constantly, change the source. On your iPhone: Settings → Camera → Formats → Most Compatible. From that point on, the camera captures JPEG and nothing needs converting again.
The trade-off is real, though — you will use roughly twice the storage per photo, and you lose HEIC's deeper colour support. A reasonable middle ground is to leave the camera on High Efficiency and convert only the handful of photos you actually need to send somewhere. There is also a subtlety worth knowing: when you AirDrop or share to certain apps, iOS sometimes converts to JPEG automatically and sometimes doesn't, which is precisely why the problem shows up unpredictably.
After Converting: Two Things Worth Doing
Converted JPGs from a modern iPhone are still large — 12 MP at high quality is a few megabytes each. If they're headed for a website, an email, or a form with a size limit, run them through the Image Compressor afterwards; halving the file size again with no visible difference is routine.
And if you photographed a multi-page document, the Images to PDF tool will bundle the converted pages into one properly ordered PDF — which is what most people actually wanted when they photographed the paperwork in the first place.
Frequently Asked Questions
Why won't my iPhone photos open on Windows?
Because they're HEIC, not JPEG. Windows can display HEIC only after installing Microsoft's HEIF Image Extensions, which depends on a paid HEVC codec package. Converting to JPG avoids the whole issue.
Is there a limit on how many photos I can convert?
No. There's no server metering usage — the only practical limit is your device's memory when converting very large batches at once.
Do my photos get uploaded anywhere?
No. Decoding happens in your browser via WebAssembly and encoding via your browser's canvas. The photo never leaves your device.
Convert your camera roll with the HEIC to JPG Converter, shrink the results with the Image Compressor, or bundle them up with Images to PDF — all free, all local.