HDR Photo Viewer
See what an HDR boost actually changes
Drop in a photo, or an existing gain-map HDR file, and compare the original against the HDR result — split-screen or side-by-side, with a real simulated preview of the boost.
Open the viewerLocal-first processing · No account required
Side-by-side or split comparison
Switch between a side-by-side layout and a draggable split-screen slider, so you can see exactly where a boost changes an image and by how much — highlight by highlight, not just as an overall "does this look different" impression.
Built on the same math as the actual encoder
The preview isn't a separate, simplified approximation — it runs the identical tone-mapping curve Encode uses to build a real gain map, including the soft-knee highlight compression that keeps near-clipped highlights separated instead of flattening them together. What you see here is what you'd actually get from an export.
Questions people actually ask
Is this a real HDR preview, or just a brightness filter?
It's a genuine simulation of the same tone-mapping math the Encode tool uses to build a real gain map — not a generic brightness or contrast filter layered on top. What you see reflects the actual boost curve, including the soft-knee highlight rolloff a real HDR-capable display would show.
Can I view a gain-map HDR file I already have, not just create one?
Yes — drop in an existing gain-map JPEG and the viewer decodes and displays both the primary image and, where present, the embedded gain map itself, alongside a simulated boosted result.
Does my photo get uploaded anywhere?
No. Decoding, tone-mapping, and rendering all run locally in your browser. Nothing is sent to a server at any point.