What this guide can and cannot say
HEIC support in Photoshop and Lightroom depends on your version and setup, and it changes over time. This guide does not list versions or menu names. For those, check Adobe’s current documentation for your exact version. The same applies to GIMP: check the current GIMP documentation.
What follows is the part we can support: how to bring a HEIC into editing software safely when you are not sure the software reads it.
The safe path: convert first, edit the copy
If your editor opens the HEIC directly, test with one photo and verify three things: orientation is right, colours match what you saw on the phone, and the image is the full resolution. If any of them is wrong, convert before editing.
Choose the output by your goal:
- TIFF for editing and print. FromHEIC’s HEIC to TIFF writes uncompressed baseline TIFF at 8-bit or 16-bit per channel, with the ICC profile embedded and optional date, camera and settings. A 16-bit TIFF keeps real extra precision only when the HEIC has more than 8 bits; an 8-bit source is simply scaled, and the result says so. Files are large.
- PNG for lossless output without compression artefacts, with transparency when the HEIC has an alpha auxiliary image. See HEIC to PNG. It is 8-bit.
- JPG for quick edits where a lossy file is acceptable. See HEIC to JPG. It is another lossy generation each time you save.
Colour management
iPhone photos commonly use Display P3 (ICC registry entry). Editors that honour ICC profiles (ICC specification) will display that correctly if the profile is embedded. FromHEIC can either convert pixels to sRGB (the default) or keep the original profile embedded.
- If your editor’s colour settings are unknown to you, use the sRGB default.
- If you work in a wide-gamut workflow, choose the keep-profile option, or TIFF, then confirm in your editor that it reports the profile and does not silently convert or discard it. The colour profile viewer shows what is embedded in the original.
The detail is in HDR and Display P3.
GIMP
The GIMP 2.10 release notes state that GIMP 2.10 ships native WebP support (import and export, including ICC profiles and metadata), and describe a metadata viewer and editor (including GPS data). They do not mention HEIC. So we cannot tell you whether your GIMP build reads HEIC; it may depend on the version and how it was built. A HEIC decoding library like libheif is what many applications use, but whether yours links to it is for you to check. If it does not open, convert to PNG or TIFF first.
Photoshop and Lightroom
Check Adobe’s current HEIC documentation for: whether your version opens HEIC natively, how it treats the colour profile, whether it needs an operating system component, and how it imports from a phone. If the answer is unclear, convert to TIFF or PNG, import that, and keep the HEIC as the master.
Metadata
Editors differ in what they preserve. In FromHEIC conversions, GPS is excluded by default and “Keep date, camera and settings” is a separate option. If your catalogue relies on capture dates for sorting, tick it, or you will get files that sort by modification date. See metadata and GPS.
Orientation
FromHEIC applies HEIC rotation to the pixels and resets the output orientation, so the converted file is upright in any editor. If you open the HEIC directly and it appears sideways, that is the editor not applying the container rotation. See orientation and colour.
Batch work
For a shoot’s worth of photos, use the batch converter to produce TIFF or PNG for all of them with one set of options, then import the folder. Apple’s note that USB import might convert HEIF to JPEG unless Keep Originals is set is worth remembering when you pull photos from an iPhone to your editing computer.
Summary
What each conversion does is documented on its tool page. To see how Adobe or GIMP handle HEIC, test one file, look at orientation and colour, and consult the vendor.