XPM to HDR Converter

Migrate XPM bitmaps to HDR format online and for free

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Simple Interface

Three steps to convert: upload your XPM, select HDR, and download. The clean interface makes the process intuitive even for first-time users.

Lightning Fast

XPM files are small and convert to HDR in seconds. The cloud-based engine handles the transformation quickly so you can download right away.

Batch Processing

Upload multiple XPM files at once and convert them all to HDR in a single session — ideal when you have many legacy images to migrate.

How to convert XPM to HDR

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose hdr or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your hdr file right afterwards

About formats

XPM (X PixMap) is a color image format for the X Window System, developed by Arnaud Le Hors at GROUPE BULL beginning in 1989 as the color successor to the monochrome XBM format. Like XBM, XPM files are valid C source code — each file defines the image as a static array of character strings, where the header strings specify width, height, number of colors, and characters per pixel, the color definition strings map character codes to color values (supporting X11 color names, hexadecimal RGB, and symbolic color types like 'background' and 'foreground'), and the pixel strings encode each row as a sequence of character codes that index the color palette. This ASCII art representation makes XPM images human-readable: one can often see the image content directly in the text of the source file. The format went through three revisions: XPM1 (1989, compatible with X10), XPM2 (simplified syntax), and XPM3 (1991, the current version with the static char* syntax and extended color specification). XPM was the standard format for X Window application icons, splash screens, pixmap buttons, and themed UI elements throughout the 1990s and 2000s. One advantage is the combined benefits of being a valid C source file and a color image: XPM files can be compiled into applications, edited in any text editor, processed by text tools, and version-controlled, while supporting up to 256 colors with transparency (using the 'None' color keyword). The X11 ecosystem's reliance on XPM ensures broad tool support. XPM files are handled by all X11 toolkits, ImageMagick, GIMP, and web browsers (legacy support).
Initial release: 1989
HDR (also known as RGBE or Radiance HDR) is a high-dynamic-range image format created by Greg Ward Larson as part of the Radiance lighting simulation system, developed at Lawrence Berkeley National Laboratory starting in 1985 with the HDR format emerging around 1989. The format stores floating-point RGB pixel values using a compact 32-bit-per-pixel encoding called RGBE (Red, Green, Blue, Exponent): three 8-bit mantissa bytes share a single 8-bit exponent, representing luminance values across a range of roughly 76 orders of magnitude while keeping file sizes comparable to standard 24-bit images. HDR files begin with a text header containing rendering and exposure metadata, followed by the RGBE pixel data compressed with a scanline-oriented run-length encoding scheme. The format captures the full luminance range of real-world scenes — from deep shadows to direct sunlight — enabling physically accurate lighting calculations, tone mapping to different display conditions, and post-capture exposure adjustment without the clipping artifacts inherent in 8-bit formats. One advantage is the format's foundational role in HDR imaging: Radiance HDR pioneered the concept of storing real-world luminance values in image files, and the .hdr format became the standard for light probe images and environment maps used in image-based lighting across the 3D rendering industry. The format's compact encoding is another practical strength — the RGBE scheme provides far more dynamic range than 8-bit formats while using only 33% more storage per pixel, a favorable tradeoff that made HDR practical on storage-limited systems of the late 1980s. HDR files are supported by Photoshop, GIMP, ImageMagick, Blender, and all major 3D renderers.
Developer: Greg Ward Larson
Initial release: 1989

Frequently Asked Questions

Why would I convert XPM to HDR?

XPM is tied to X11/Linux desktops. Switching to HDR gives you high dynamic range image for lighting simulation and broad support across platforms, browsers, and devices.

How do I open a HDR file?

Software that handles HDR includes Photoshop, GIMP, HDRShop, Luminance HDR, Blender — giving you options on every major operating system.

How long does XPM to HDR conversion take?

Conversion is nearly instant for most XPM files. Since these are small images, the entire process — upload to download — takes only moments.

Can I convert multiple XPM files to HDR at once?

Absolutely. Batch upload your XPM images and convert them all to HDR in a single pass — no need to repeat the process for each file.

What exactly is the XPM format?

XPM is a color pixmap format for X Window System. Originally from X11/Linux desktops, it has become a legacy format — conversion is the most practical way to use these images today.

Does this converter work on mobile devices?

The converter is browser-based and fully responsive. Convert XPM to HDR from any device — desktop, laptop, tablet, or smartphone.