The short version
- Apple Reference Image lets you compare a photo’s main image with a reference image in Photos.
- The reference preserves what the camera sensor saw when you took the photo in Reference mode.
- Comparing the two images lets you look for edits made after capture.
Compare the reference and main image in Photos
Photos displays the reference image alongside the main image, like a digital negative, so you can visually compare the two. Look for differences between them to determine whether the photo was edited after capture.
How Reference mode creates the reference image
iPhone 18 Pro and iPhone 18 Pro Max support the feature through the new sensor in their 48MP Fusion Main camera.
The sensor can sign every pixel it sees, with secure pixel-level signing taking place at capture. When you shoot in Reference mode, the camera collects that signed sensor data. Private Cloud Compute then develops the data into an unalterable reference image.
Which signal answers your photo question?
Signal picker: choose a question about a photo, whether it was edited after capture or generated or edited with AI, to see which Apple signal answers it and when that signal is available.
Reference images are not limited to Photos. APIs in iOS 27, iPadOS 27, and macOS 27 let third-party apps enable viewing of them.
What each image-authenticity signal tells you
Apple presents Reference Image, image metadata and SynthID as one set, which it calls “vital for photojournalists, photographers, and everyday viewers.”
Three signals Apple lists for photos
| Signal | What it tells you |
|---|---|
| Apple Reference Image | Records what the sensor saw at capture for comparison with the main image. |
| Image metadata | Can help identify images generated or edited with AI. |
| SynthID | Can also help identify images generated or edited with AI. |
SynthID support arrives in a software update later this year.
FAQs
Is Apple Reference Image enabled automatically?
No. Apple Reference Image is opt-in, so you choose whether to enable it.
Is Apple Reference Image available in China at launch?
No. Apple Reference Image will not be available in China at launch because of regulatory requirements.
What can users in the EU do at launch?
In the EU, reference-image capture will not be available at launch on iPhone 18 Pro models. Users with iOS 27, iPadOS 27, and macOS 27 will still be able to develop and view reference images.
Will SynthID be included for every edited image?
No. SynthID will be included for most edited images, depending on the edits applied.
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