Images · Free browser tool
Private Ultra HDR Image Converter
Convert an opaque JPG, PNG, or WebP into a backward-compatible Ultra HDR JPEG, or turn an Ultra HDR JPEG back into a plain SDR image. Both directions are verified locally.
Runs on this device
No file upload
Free to use
Private workspace
Create or remove an HDR gain map without uploading the image, then download only after the new JPEG passes local structural and image checks.
Ready.
Selected file— · Reading…
Choose a file to begin
Create or remove an HDR gain map without uploading the image, then download only after the new JPEG passes local structural and image checks.
Verified locally
Verified JPEG ready
The preview shows the SDR fallback. A compatible HDR viewer may apply the verified gain map.
- Original
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- Output
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- Difference
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What this tool does
A focused job, with a visible boundary.
Create or remove an HDR gain map without uploading the image, then download only after the new JPEG passes local structural and image checks.
Natural, Glow, and Graphic highlight profiles
Locally decoded and verified JPEG output
Know the limits
Local does not mean unlimited.
Browser processing protects the file from an upload workflow, but the browser, device, output format, and selected settings still matter.
- SDR-to-HDR adds display headroom to existing highlights; it cannot recover uncaptured detail or replace a true HDR capture workflow.
- Transparent and animated inputs are not supported because the Ultra HDR base rendition is an opaque still JPEG.
- HDR rendering depends on the display, viewer, brightness settings, and whether later editing or sharing preserves the gain map.
Four local steps
How to use ultra hdr converter.
- 01
Choose one opaque still JPG, PNG, WebP, or Ultra HDR JPEG.
- 02
For an SDR source, select Natural, Glow, or Graphic highlight response; Ultra HDR sources are automatically prepared for SDR output.
- 03
Create the JPEG and wait while its container and embedded images are checked locally.
- 04
Download the verified Ultra HDR or plain SDR JPEG.
Clear answers
Ultra HDR converter questions.
What does SDR to Ultra HDR create?
It keeps a normal SDR JPEG as the fallback, adds a smaller JPEG gain map, and includes the metadata and MPF index that compatible HDR viewers use to show brighter highlights.
Can it convert Ultra HDR back to a normal JPG?
Yes. The converter uses the stored SDR base rendition, re-encodes it as a plain JPEG, and verifies that the result no longer declares a gain map.
Will every screen show the HDR effect?
No. Readers without gain-map support display the ordinary SDR fallback. HDR appearance also depends on the display, operating system, viewer, brightness, and any later re-encoding.