FITS Won't Open? Convert to JNG Instantly
Fast, instant FITS to JNG conversion. No signup required. Just drop your .fits file and get .jng in seconds.
Batch Settings
About FITS to JNG Conversion
Dealing with a FITS file that won't open on your device? You're not alone — FITS compatibility issues are one of the most common reasons people search for a file converter. FITS is a widely used file format.
The fix is simple: convert your FITS to JNG. JNG is a widely used file format. This conversion lets you convert between formats quickly, solving the problem in seconds rather than hours of troubleshooting.
Converting FITS to JNG maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert processes your FITS file on secure servers in Germany — upload, convert, download. Your files are encrypted via TLS and automatically deleted within 24 hours. No account needed, no software to install, and it works on any device with a browser.
This conversion is ideal when you When you need a JNG file.
The conversion engine behind CocoConvert uses FFmpeg, Sharp, and qpdf — the same open-source libraries trusted by Netflix, YouTube, and enterprise platforms. Pro users can batch convert up to 100 files at once.
How to Convert FITS to JNG
- 1
Add your FITS file
Drag and drop your .fits file into the converter, or tap "Browse" to pick it from your device. Multiple files are supported for batch processing.
- 2
Pick JNG output
Select .jng as the target format. CocoConvert automatically applies the best quality settings for this conversion.
- 3
Start conversion
Hit the Convert button. The image engine processes your file server-side — no CPU drain on your device.
- 4
Save your file
Once done, download your .jng file. For batch jobs, download all at once as a zip.
What Happens When You Convert FITS to JNG
Your FITS file is decoded and re-encoded as JNG.
Your FITS file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in JNG format
The converted file is ready for download
Format Comparison
FITS
.fits file
| Extension | .fits |
| MIME Type | image/fits |
| Category | Image |
JNG
.jng file
| Extension | .jng |
| MIME Type | image/x-jng |
| Category | Image |
Should You Convert FITS to JNG?
When to Convert
- ✓When you need a JNG file
Frequently Asked Questions
Why won't my FITS file open?
FITS files may not open if your device lacks the right codec or application. Converting to JNG — a more widely supported format — usually resolves this. JNG is a widely used file format.
Is it safe to convert FITS to JNG online?
Yes. CocoConvert encrypts your file via TLS, processes it on isolated servers in Germany, and permanently deletes it within 24 hours. Your files are never shared or analysed.
Will I lose quality converting FITS to JNG?
Converting FITS to JNG maintains high quality with CocoConvert's optimised encoder settings. CocoConvert uses high-quality encoder defaults to preserve as much fidelity as possible.
How large can my FITS file be?
Free users can convert files up to 250 MB each. Pro users get a 5 GB limit per file, and Business API users have custom limits.
Can I convert FITS to JNG on my phone?
Absolutely. CocoConvert works in any modern browser — iOS Safari, Android Chrome, and all desktop browsers. No app required.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.