FITS to PNG Converter
Processing entirely on your device — large files may take a moment.
Convert to PNG when you need lossless quality or a transparent background — for logos, UI screenshots and line art. If your files are still in FITS format, this page is the shortcut: 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.
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 FITS compares to PNG
| FITS | PNG | |
|---|---|---|
| Compression | None (optionally Rice/GZIP) | Lossless (DEFLATE) |
| Transparency | Not supported | Full alpha (8/16-bit) |
| Animation | Not supported | Only via APNG extension |
| Metadata | Rich text header (WCS) | tEXt chunks, ICC profile |
| Best for | Telescope frames, science data | Screenshots, logos, sharp graphics |
How to convert FITS to PNG
- 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 PNG". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted PNG 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 PNG format
PNG was created in 1996 as a free, open replacement for the patent-encumbered GIF, and it has been the reference lossless image format ever since. Pixels are compressed with the DEFLATE algorithm (the same one inside ZIP files), which reproduces the original image exactly — bit-for-bit — while supporting full 8-bit or 16-bit alpha transparency. Screenshots, logos, icons, charts and anything with text or sharp edges should live in PNG.
Because it never discards information, PNG files of photographs are several times larger than JPG — that is the price of perfection. Modern PNG encoders add filters per scanline that make screenshots and flat-color graphics compress surprisingly well. PNG also became the base of APNG, the animation extension that browsers play natively.
+Strengths
- ✓Truly lossless — every pixel survives exactly as it was
- ✓Full alpha transparency with smooth edges, not 1-bit masks
- ✓Open standard, unpatented, with excellent tooling everywhere
- ✓Ideal for text, line art and flat-color graphics — sharp edges stay sharp
!Limitations
- −Photographs become several times larger than JPG
- −Base format has no animation (that is the APNG extension)
- −16-bit or high-resolution PNGs can grow very heavy
Why convert FITS to PNG?
Think of it as moving your file to the container that fits the job. Not display-ready PNG works differently: Truly lossless — every pixel survives exactly as it was If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this FITS to PNG 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 PNG?
No — PNG 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.
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.
Will transparent areas survive the conversion to PNG?
Transparency is kept whenever PNG 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.