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.
Typical use: Convert FITS frames to PNG or JPG to preview telescope data, or pack them into a ZIP for sharing.
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
- Compression
- None (optionally Rice/GZIP)
- Transparency
- Not supported
- Animation
- Not supported
- Metadata
- Rich text header (WCS)
- Best for
- Telescope frames, science data
Convert FITS to…
48 direct directions plus 12 workflows, sorted A–Z; 🔥 marks popular targets.
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Frequently asked questions
What is a FITS file?
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.
How do I convert FITS files online?
Pick a target format from the "Convert FITS to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert FITS files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can FITS convert to?
This page lists all 60 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.