XPM to HDR Converter
Processing entirely on your device — large files may take a moment.
X11 Pixmap and Radiance HDR Image exist for different jobs: XPM (X11 Pixmap) is an image written as C source code — plain ASCII text that compilers and editors ingest directly, the classic icon format of Linux desktops and legacy X11 apps. Converting HDR to PNG produces a tone-mapped preview usable in any image viewer.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How XPM compares to HDR
| XPM | HDR | |
|---|---|---|
| Compression | None (ASCII text) | RGBE (RLE runs) |
| Transparency | Single transparent color | Not supported |
| Animation | Not supported | Not supported |
| Metadata | Not supported | Radiance comments |
| Best for | Linux icons, X11 themes | Lighting data, environment maps |
How to convert XPM to HDR
- 1
Select your files
Drag & drop your XPM files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to HDR". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted HDR file individually, or grab everything at once as a ZIP archive.
About the XPM format
XPM (X11 Pixmap) is an image format that is literally C source code: pixels are listed as character-to-color mappings inside an ASCII array. Compilers, text editors and version control all treat it as plain text, which is why Linux desktop icons and legacy X11 application assets have used it for decades.
XPM is limited to 256 colors per image and stores no alpha beyond a designated transparent character, so it is a niche target: mainly icon themes, window-manager decorations and retro programming projects.
+Strengths
- ✓Plain text — diffs and greps
- ✓Compiles straight into C programs
- ✓Tiny for small flat icons
!Limitations
- −256 colors maximum
- −Poor alpha (one transparent color)
About the HDR format
HDR (Radiance RGBE) is the veteran high-dynamic-range format of lighting research and 3D rendering: pixels stored as a shared 8-bit exponent plus per-channel mantissas, letting one file hold both a sun and a shadow with no clipping. HDRI environment maps for 3D scenes are almost always HDR files.
Standard image viewers show it badly or not at all, because the values can exceed what a screen can display. Converting HDR to PNG tone-maps the file into an 8-bit preview — good for quick inspection, though the floating-point original remains the render-grade master.
+Strengths
- ✓True high-dynamic-range values
- ✓The standard of HDRI environment maps
- ✓Compact for its precision
!Limitations
- −Not display-ready — needs tone mapping
- −Viewer support is scarce
Why convert XPM to HDR?
Converting makes sense where the strengths of HDR meet what XPM cannot give you. True high-dynamic-range values Meanwhile 256 colors maximum One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this XPM to HDR converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Will I lose quality converting XPM to HDR?
No — HDR is a lossless format, so every pixel of the converted image matches your original XPM file. You can also adjust the quality/size balance before converting when the target format supports compression.
Can I convert several XPM files at once?
Yes — drop as many files as you like into the tool and they are converted in one batch. When more than one file comes out, everything is bundled into a ZIP for a single download.
Will transparent areas survive the conversion to HDR?
Transparency is kept whenever HDR actually supports an alpha channel. If the target format has none (like JPG), transparent areas are flattened onto a white background — that is a property of the format, not of this tool.