What is an HDR file?
An .HDR file is primarily a High Dynamic Range Image File. It stores image data with a wider range of colors and brightness than standard images. Originally developed for the Radiance lighting simulation software, it is now widely supported by companies like HDRsoft.
However, .HDR files can also be header files. Different industries use them to store text-based metadata for related raw data files. Examples include geospatial raster images from ENVI, medical imaging data in the Analyze 7.5 or NIfTI format, and spatial data from ESRI.
How to open HDR files?
To open an .HDR image, you can use photo editing software like Adobe Photoshop, GIMP, or Photomatix. For header files, you need the specific software that matches the data. For example, use ENVI for geospatial data, Amira for medical imaging, or specialized database tools from InterSystems.
Best practices and troubleshooting
Because the .HDR extension is used by many different systems, you must know what kind of file you have. If an image editor fails to open the file, it is likely a text-based header file. You can open a header file with a text editor like Notepad++ to read the metadata and identify its origin. If you want to share an .HDR image on the web, recommend converting it to sensible target formats like .JPG or .PNG on convert.guru.
Software and tools
Because .HDR has multiple possible meanings, we recommend using viewer.online/hdr to identify the actual format of your file. viewer.online/hdr analyzes .HDR files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
Summary
viewer.online/hdr directly opens and previews .HDR files in the browser, eliminating the need to install software or troubleshoot compatibility issues.