PRACTICAL GUIDE
How to Convert HEIC to JPG Without Uploading Your Photos
Why an iPhone photo will not open on someone else's computer, how to convert it on your own device, and what the conversion costs you.
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Why your phone made a file nobody can open
HEIC is a container around HEVC, the same compression used for video. For a photograph it is roughly twice as efficient as JPG at the same visual quality, which is why Apple switched to it: the same camera roll takes half the space.
The cost is compatibility. HEVC is patent-encumbered, so support was never universal, and plenty of Windows machines, older Android phones, upload forms, print shops and web applications still cannot read the file at all. The photo is fine. The rest of the world just cannot open it.
The conversion happens on your device
A browser cannot decode HEIC on its own, so the decoder has to be downloaded: about seven hundred kilobytes, once, cached by your browser afterwards. On a slow connection the first conversion waits for that download; every one after it is close to instant.
What is worth noticing is what does not happen. The photograph itself is never uploaded. That matters here more than for most conversions, because the files people need to convert out of HEIC are, almost by definition, personal photographs.
What you give up by converting
JPG is the older, less efficient format, so the same picture at comparable quality becomes a bigger file. You also lose whatever HEIC-specific features the original carried: depth information, the burst or Live Photo frames, and in some cases a wider colour range. For sharing and uploading none of that matters. For your archive it does, which is the argument for converting a copy and keeping the original.
Convert first, then resize or compress
If the destination has a file size limit, do the format conversion first and treat the resulting JPG as your starting point. Trying to shrink a HEIC before converting is working with a format most tools cannot read, and converting a heavily reduced file just bakes in the reduction. Convert, then resize to the dimensions you need, then compress if the limit is still not met.
Or stop your phone making them
On an iPhone, Settings then Camera then Formats offers Most Compatible, which records JPG directly. You lose the storage saving and gain never having this problem again. There is also a middle path: leave the camera on High Efficiency and set Transfer to Mac or PC to Automatic, which converts on the way out.
Frequently asked questions
Is my photo uploaded to convert it?
No. The decoder runs in your browser and the conversion happens on your own device. Nothing about the image is sent to a server, which is the point: a photograph is not something to hand to a stranger's machine in order to change its file extension.
Why is the first conversion slow?
A browser has no built-in HEIC decoder, so one has to be downloaded the first time you convert something — around seven hundred kilobytes. It is then cached, so later conversions in the same browser skip the wait entirely and take a fraction of a second.
Will the JPG be bigger than the HEIC?
Usually, yes. HEIC is roughly twice as efficient, so the same photograph at comparable quality lands in a larger JPG. If the result needs to be under a size limit, compress or resize the JPG afterwards rather than converting at a very low quality setting.
Does the location data survive the conversion?
It should not: the image is decoded and re-encoded from pixels, which leaves the metadata block behind. If you want to see what a file was carrying and confirm it is gone, the metadata remover reports both before and after.