How to Batch Convert iPhone Photos to JPG or PNG
Convert a folder of iPhone HEIC photos to compatible JPG or editable PNG files in one private batch, without uploading the originals.

If you have a folder full of iPhone photos that will not open in another app, you probably need JPG copies. You do not need to change anything on your phone or convert the photos one at a time.
Keep the original HEIC files somewhere safe, then make a new folder for the converted photos. That gives you easy-to-open JPGs without throwing away the smaller originals from your iPhone.
What HEIC is, and which format to choose
Recent iPhones normally save photos as HEIC. It is good at keeping file sizes down, but some websites and older apps still do not accept it. JPG is the simple choice for normal photos. PNG is mainly useful for screenshots and graphics, and it will usually make an iPhone photo much larger.
A Live Photo also has a short video attached to it. Converting the HEIC image gives you an ordinary still photo; it does not put that movement inside the JPG. Keep the original export if you want the Live Photo to keep working later.
How to convert a folder of iPhone photos
Make a folder for the JPG copies
Leave the HEIC originals where they are and create a second folder called something obvious, such as Holiday photos - JPG. This makes it very hard to replace the originals by accident.
Drag the HEIC photos into How to Convert
You can select the whole group in Finder or File Explorer and drag it into the app. Check that the number of files in the app matches the number you selected.
Choose JPG
Select JPG once as the output format. I would only choose PNG if these are screenshots or you have a specific reason to need it.
Click Convert and save the new folder
Open a portrait photo and a landscape photo when it finishes. If both look the right way up and the colours look normal, save the rest into the new folder.
Common problems
A photo is sideways
The original stored its rotation as extra information and the receiving app ignored it.
Try the JPG in another viewer. If it is still sideways, rotate the copy and save it; do not delete the HEIC original.
The new files are huge
You chose PNG for ordinary camera photos.
Convert the HEIC files to JPG instead. PNG is rarely the right answer for a normal photograph.
The Live Photo no longer moves
A JPG can only contain the still image.
Use the JPG for sharing and keep the original Live Photo export for your archive.
Frequently asked questions
Does HEIC to JPG reduce quality?
JPG does compress the photo again, so keep the HEIC original. At a normal quality setting, the JPG is usually perfectly good for sharing, websites and everyday use.
Should I delete the HEIC files afterwards?
I would not. They are your original photos and normally take less space than PNG copies.
Can I convert hundreds at once?
Yes. Add the whole selection, choose JPG once and convert the batch. Test two or three photos first if the folder is important.
Do the photos have to be uploaded?
No. The desktop app converts the batch on your computer.
Extra: A quick check for dates, location and Live Photos
If the dates or GPS location matter to you, check one converted photo in the Photos app or its file information before doing a large archive. Different apps do not always copy every piece of photo information in exactly the same way.
For Live Photos, keep the original HEIC and its matching video file together. The JPG is best treated as a convenient copy for sharing, not a replacement for the iPhone original.