FITS to APNG 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 an animated GIF to APNG to keep smooth color and clean transparency while staying animated.
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 FITS to APNG
- 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 APNG". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted APNG 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 APNG format
APNG (Animated PNG) is what GIF should have been: the same PNG file format with an animation extension — every frame in full 24-bit color with 8-bit alpha, no 256-color palette, no binary transparency with jagged edges. All modern browsers render it natively.
GIF has one job APNG does better in every dimension: color fidelity and clean transparency for animation. Converting an animated GIF to APNG keeps every frame but upgrades color depth and kills the halo around transparent edges. The only cost is file size — true color costs bytes.
+Strengths
- ✓Full 24-bit color per frame (no 256-color palette)
- ✓8-bit alpha transparency — no jagged edges
- ✓Native rendering in every modern browser
!Limitations
- −Larger files than GIF for the same animation
- −Legacy tools may show only the first frame
- −Not accepted by some social platforms
Why convert FITS to APNG?
Think of it as moving your file to the container that fits the job. Not display-ready APNG works differently: Full 24-bit color per frame (no 256-color palette) 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 APNG 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 APNG?
No — APNG 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.
Will transparent areas survive the conversion to APNG?
Transparency is kept whenever APNG 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.
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.