Ultra HDR vs HDR10 and Dolby Vision
It's easy to mix up the HDR names. HDR10 and Dolby Vision are video standards — they describe HDR for movies, TV and streaming. Ultra HDR is the photo standard. They solve the same idea (brighter highlights) for different media. Here's how they differ and which one your images actually use.
See the difference
HDR10 and Dolby Vision: HDR for video
HDR10 and Dolby Vision are formats for video — they tell a TV or player how to display bright, high-contrast footage, using metadata about brightness levels (and, for Dolby Vision, per-scene or per-frame data). They're built for streaming, Blu-ray and game consoles. They do not apply to still photos.
Ultra HDR: HDR for photos
Ultra HDR is the still-image equivalent: a JPEG with an embedded gain map, standardized as ISO 21496-1 with Adobe's gain-map XMP. It's what makes the photos on iPhone, Android, Instagram and Google Photos glow. Google named it 'Ultra HDR' on Android; Apple uses the same ISO gain-map approach for iPhone HDR photos.
Same goal, different mechanism
All of them aim to show highlights brighter than ordinary white on a capable display. But video HDR carries brightness as stream metadata for a decoder, while Ultra HDR carries it as a gain map embedded in the image, with a normal JPEG underneath for compatibility. That's why an Ultra HDR photo opens anywhere a JPEG does.
Which one do my images use?
Your photos use Ultra HDR (gain-map / ISO 21496-1) — not HDR10 or Dolby Vision. If a friend sends an 'HDR photo' from their iPhone, it's a gain-map image. HDR10 and Dolby Vision apply to video; MakeHDR can also convert video to true HDR (BT.2020, PQ or HLG), which is a separate path from the photo gain map.
How to make an Ultra HDR photo
MakeHDR turns any JPEG, PNG or HEIC into a standards-compliant Ultra HDR photo in your browser — it builds the gain map locally, with no AI and no upload, so your image glows on HDR screens and stays a normal JPEG everywhere else.