PNG24 to FITS Converter
Processing entirely on your device — large files may take a moment.
PNG (24-bit Truecolor) and Flexible Image Transport System exist for different jobs: PNG24 is the common name for 24-bit truecolor PNG — full RGB, no alpha channel (PNG32 adds alpha). It is what most people simply call PNG. Convert FITS frames to PNG or JPG to preview telescope data, or pack them into a ZIP for sharing.
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 PNG24 compares to FITS
| PNG24 | FITS | |
|---|---|---|
| Compression | Lossless (DEFLATE) | None (optionally Rice/GZIP) |
| Transparency | Full alpha (8/16-bit) | Not supported |
| Animation | Only via APNG extension | Not supported |
| Metadata | tEXt chunks, ICC profile | Rich text header (WCS) |
| Best for | Screenshots, logos, sharp graphics | Telescope frames, science data |
How to convert PNG24 to FITS
- 1
Select your files
Drag & drop your PNG24 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 PNG24 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
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 PNG24 to FITS?
Converting makes sense where the strengths of FITS meet what PNG24 cannot give you. Self-documenting science headers Meanwhile Photographs become several times larger than JPG One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this PNG24 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 PNG24 to FITS?
No — FITS is a lossless format, so every pixel of the converted image matches your original PNG24 file. You can also adjust the quality/size balance before converting when the target format supports compression.
Can I convert several PNG24 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.
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 PNG24 files matters (camera model, GPS, timestamps), keep the original file as the master and treat the converted copy as the shareable version.