FITS Won't Open? Convert to JXL Instantly
Fast, instant FITS to JPEG XL conversion. No signup required. Just drop your .fits file and get .jxl in seconds.
Batch Settings
天文学の深淵を覗き見るFITSファイルと、次世代の画像圧縮技術JXL。これら二つの形式は、それぞれ異なる目的でその真価を発揮します。FITSが膨大な科学データを正確に保持する一方で、JXLはその高効率な圧縮と豊かな表現力で、デジタルコンテンツの未来を切り開いています。このページでは、FITSで蓄積された貴重なデータを、JXLの利点を最大限に活かした形で変換するお手伝いをいたします。高解像度画像を劣化させることなく、ファイルサイズを劇的に削減したい。あるいは、より柔軟な画像処理環境へと移行したいとお考えの方にとって、この変換は強力な一歩となるでしょう。当社の変換ツールは、複雑な設定なしに、迅速かつ正確なファイル変換を実現します。
- 学術論文の図版
- ビジネスレポートの挿絵
- 高精細な漫画原稿
日本では、特に高精細な画像が求められる漫画やイラスト制作において、JXLの可逆圧縮と広色域対応は、新たな表現の可能性を広げると期待されています。また、縦書き文書との親和性も考慮され始めています。
About FITS to JPEG XL 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 JXL. JPEG XL is a next-generation format with both lossless and lossy modes, aiming to replace JPEG and PNG. This conversion lets you convert between formats quickly, solving the problem in seconds rather than hours of troubleshooting.
Converting FITS to JXL 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 JXL 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 JPEG XL
- 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 JXL output
Select .jxl 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 .jxl file. For batch jobs, download all at once as a zip.
What Happens When You Convert FITS to JPEG XL
Your FITS file is decoded and re-encoded as JXL.
Your FITS file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in JXL format
The converted file is ready for download
Format Comparison
FITS
.fits file
| Extension | .fits |
| MIME Type | image/fits |
| Category | Image |
JPEG XL
.jxl file
| Extension | .jxl |
| MIME Type | image/jxl |
| Category | Image |
Should You Convert FITS to JPEG XL?
When to Convert
- ✓When you need a JXL 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 JXL — a more widely supported format — usually resolves this. JPEG XL is a next-generation format with both lossless and lossy modes, aiming to replace JPEG and PNG.
Is it safe to convert FITS to JXL 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 JXL?
Converting FITS to JXL 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 JXL 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.