What is a .HDR file?
HDR is a Radiance high-dynamic-range image, storing a huge brightness range.
- Did you know
- Radiance HDR, from 1989, let computer graphics capture real-world light levels.
- The Radiance HDR format was created by Greg Ward as part of the Radiance lighting-simulation system at Lawrence Berkeley National Laboratory.
- It uses an RGBE encoding in which three colour bytes share a single exponent byte, capturing a vast brightness range in just 32 bits per pixel.
- What Analyser reads
- Decode and preview extra still-image formats in pure JavaScript - Truevision TGA, QOI, Netpbm (PPM/PGM/PBM), PCX, farbfeld, WBMP, XBM/XPM, Sun Raster and SGI are fully rendered - and read header metadata from codec-heavy formats: Radiance HDR, DirectDraw Surface (DDS) game textures, OpenEXR, JPEG 2000, JPEG XR, EPS/PostScript, Windows WMF/EMF metafiles, Apple ICNS icons, CUR/ANI cursors, MNG and Lottie animations.
- Depth of analysis
- .HDR is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .HDR file
- Drag a .HDR file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.