iOS 27.2 began adding invisible SynthID watermarks to Image Playground outputs and some Apple Intelligence photo edits. MacRumors found marks after Extend and Reframe edits, while Clean Up results varied with edit size. SynthID embeds a signal within the image rather than relying on file metadata and is designed to withstand common cropping or compression. Detection is available through the SynthID Detector website, not an on-device iPhone detector. It does not cover every AI tool or small edit, so a negative result must not be treated as proof of authenticity.