What is the JXR file format?
.jxr is a raster (pixel-based) image file format based on the JPEG XR standard - an improvement over JPEG and JPEG 2000. Developed by Microsoft (originally released as "Windows Media Photo" and later "HD Photo") and standardized in 2009 as ISO/IEC 29199-2, it offers better color reproduction and supports high bit depths, including 16-bit integer and 32-bit floating-point channels for HDR and wide-gamut imagery.
.jxr supports higher lossy compression ratios than JPEG, and .jxr files are typically around half the size of a comparable JPEG image at equivalent quality. Lossless compression is also available. The codec uses a lapped biorthogonal transform and adaptive entropy coding, stored in a TIFF-like container.
.jxr is not the only format based on the JPEG XR standard - related formats include .hdp and .wdp. Since 2013, a BSD-licensed open-source libjxr library has been available for developers. Today the format is most commonly encountered as the save format for Xbox HDR game screenshots; despite ISO standardization, browser support never became widespread, and for HDR work it has largely been superseded by HEIC and AVIF.
Security & safety
RISK: LOWA JXR is image data and is safe to open in a normal viewer; it does not execute. The realistic caution is the conversion route: searching for a 'JXR viewer/ converter' often surfaces ad-heavy download sites and PUP-bundled installers - prefer XnView, ImageMagick or Windows' built-in Photos. As with any image format, keep your viewer updated, since image decoders have historically had parsing vulnerabilities.
Format details
in a nutshellPrograms that open JXR files
Technical details
deep spec| Encoding | Binary; compressed image data in a TIFF-like IFD container |
| Byte order | Little-endian |
| Magic bytes | 49 49 BC 01 (hex) at offset 0 - "II" + 0xBC, the JPEG XR signature (differs from TIFF's 0x2A third byte) |
| MIME type | image/jxr; legacy alias image/vnd.ms-photo |
| Color depth | Up to 16-bit integer or 32-bit floating-point per channel; up to 128 bpp including the alpha plane |
| HDR support | Yes - 16-bit and 32-bit float channels enable high dynamic range and wide-gamut content |
| Compression | Lapped biorthogonal transform (LBT) with adaptive entropy coding; lossy and lossless modes both supported |
| Color spaces | RGB, CMYK, grayscale, n-channel; wide gamut via scRGB or embedded ICC profiles |
| Alpha channel | Dedicated separate alpha plane stored alongside the image plane |
| Metadata | Embeds EXIF, XMP and ICC color profile data within the container |
| Max resolution | Up to 2^32 x 2^32 pixels per specification |
| Tiling | Supports spatial tiling for efficient partial image decoding without loading the full file |
| Typical file size | Typically ~50% of an equivalent JPEG at equal quality; far smaller than uncompressed HDR TIFF |
| Checksum/integrity | No built-in checksum or integrity verification |
| Platforms | Windows (native support); Xbox (default HDR screenshot format); macOS and Linux via XnView MP and ImageMagick with libjxr |
| Released | 2006 as Windows Media Photo / HD Photo; standardized 2009 (ISO/IEC 29199-2) |
| Latest version | ISO/IEC 29199-2:2012 (JPEG XR) |
| Open standard | Yes · royalty-free |
| Specification | www.itu.int |
JXR conversions
Community Q&A
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