FITS to PPM Converter
Processing entirely on your device — large files may take a moment.
FITS (Flexible Image Transport System) is the data format of professional astronomy — every image carries a human-readable header with telescope, exposure and world coordinates alongside the raw pixel data. Convert PPM renders to PNG/JPG to make them shareable, or emit PPM for tools that expect the raw format.
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 to convert FITS to PPM
- 1
Select your files
Drag & drop your FITS 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 PPM". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted PPM file individually, or grab everything at once as a ZIP archive.
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
About the PPM format
PPM is the color member of the netpbm trio: a header line, then uncompressed RGB triplets. It is the format every graphics course teaches first because you can write a working encoder in twenty lines — and the format every renderer exports because twenty lines is all it takes.
Files are enormous but bulletproof: converting PPM to PNG or JPG costs nothing but space savings, and PNG keeps every bit of the original data.
+Strengths
- ✓Zero-compression simplicity — unbreakable
- ✓The standard renderer/graphics-course output
- ✓Lossless conversion to PNG preserves everything
!Limitations
- −Huge files (3 bytes per pixel, raw)
- −No alpha channel
- −Browsers do not display it natively
Why convert FITS to PPM?
Converting makes sense where the strengths of PPM meet what FITS cannot give you. Zero-compression simplicity — unbreakable Meanwhile Not display-ready One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this FITS to PPM 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 FITS to PPM?
No — PPM is a lossless format, so every pixel of the converted image matches your original FITS file. You can also adjust the quality/size balance before converting when the target format supports compression.
What happens to EXIF data and other metadata?
Conversions here re-encode the image, and re-encoding generally does not carry the original metadata over. If the EXIF data of your FITS files matters (camera model, GPS, timestamps), keep the original file as the master and treat the converted copy as the shareable version.
Can I convert several FITS 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.