XBM to FITS Converter
Processing entirely on your device — large files may take a moment.
XBM is a bitmap stored as C source code — literally an array of hex bytes that a C compiler includes. It was the original X11 icon format, and it still compiles. Convert FITS frames to PNG or JPG to preview telescope data, or pack them into a ZIP for sharing.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How to convert XBM to FITS
- 1
Select your files
Drag & drop your XBM 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 FITS". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted FITS file individually, or grab everything at once as a ZIP archive.
About the XBM format
XBM is the most honest image format ever shipped: the "file" is a C source array of hex bytes, compiled straight into X11 applications as cursor and icon bitmaps. Rendered, it is 1-bit black and white — the ancestors of every pixel-art cursor you still use.
Because it compiles, XBM never died: firmware UIs, embedded icons and retro Unix tooling still want it. Converting a PNG down to XBM gives embeddable, compilable art; the other direction previews what the C array actually draws.
+Strengths
- ✓Compiles directly into C/C++ programs
- ✓Zero-payload format — text only
- ✓Still required by embedded and Unix tooling
!Limitations
- −1-bit black & white only
- −Human-hostile representation
- −X11 bit order trips up hand-rolled decoders
About the FITS format
FITS (Flexible Image Transport System) has carried professional astronomy data since 1981: every file opens with a plain-text header that records telescope, instrument, exposure, filters and world coordinates, followed by raw pixel arrays — often 16-bit or float, sometimes data cubes.
Values can be negative or far above display range, so FITS never looks right in a photo viewer. Converting to PNG applies a simple scaling pass that reveals the nebula or galaxy in the numbers — good for previews, while science pipelines keep the original.
+Strengths
- ✓Self-documenting science headers
- ✓High bit depth (16/32-bit, float)
- ✓The standard of every observatory
!Limitations
- −Not display-ready
- −Files are large and uncompressed
Why convert XBM to FITS?
Converting makes sense where the strengths of FITS meet what XBM cannot give you. Self-documenting science headers Meanwhile 1-bit black & white only One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this XBM to FITS 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 XBM to FITS?
No — FITS is a lossless format, so every pixel of the converted image matches your original XBM file. You can also adjust the quality/size balance before converting when the target format supports compression.
Will transparent areas survive the conversion to FITS?
Transparency is kept whenever FITS 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.
Can I convert several XBM 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.