Convert iPhone HEIC to JPEG on Windows (batch, in the browser)

Copy a batch of iPhone photos onto a Windows PC and Explorer will often show a blank icon, or Photos will ask for extra codecs. That is HEIC: the still-image format many iPhones write by default. JPEG is what Word, most email, and most upload boxes still expect.

Batch convert in Edge or Chrome

Open the converter in a current browser. You do not need the Microsoft Store HEVC pack for this page.
Drop several .heic or .heif files at once, or use Choose files. A USB copy from the phone, a zip from iCloud, or files sitting in Downloads all work if they are still HEIC.
Wait until each card shows a thumbnail. Conversion is one file after another so a large batch is less likely to exhaust memory.
Download each JPEG. If a form wants one attachment instead of a folder, tick the photos and build a PDF.

Open the converter

Why Windows struggles with HEIC

Apple has used HEIC since iOS 11. Windows can open it after you add Microsoft’s HEIF extensions (and, on some PCs, an HEVC codec). That is a reasonable choice if you want Photos to preview the originals. It is optional here: this page re-encodes a JPEG copy in the tab you already have.

A JPEG copy is also the practical fix when a website refuses .heic. Format is not the same as file size: a full-resolution iPhone still can still be several megabytes as JPEG. If an upload box rejects the file for size, that is a separate limit.

What this will not do

Live Photo video is omitted. Only the still is decoded.
It will not install codecs for the rest of Windows.
Very large panoramas can be slow; they are decoded in memory.

For the camera setting that writes JPEG on new shots, see why iPhone photos are HEIC and how to get a JPEG that will upload.