Bulk FITS to JXL Converter Online — Free HD Quality

Drag and drop your multiple FITS files into this free online FITS to JXL converter (.fits to .jxl), and click the Convert button to bulk convert them to JXL format in HD quality. Use the quality slider to fine-tune your JXL output, then download your converted files one by one or as a single ZIP — your original FITS files are removed from our servers right after.

To:
85%

Drop images here or click to browse

PNG, JPG, WebP, GIF, HEIC, RAW, PSD, SVG and more

Max 100MB per file

FITS vs JXL — File Format Comparison

Feature FITS JXL
File Extension .fits .jxl
MIME Type image/fits image/jxl
Compression Type Lossless Lossy & Lossless
Transparency Support No Yes
Animation Support No Yes
Metadata Support Yes Yes

What Is FITS Format?

Flexible Image Transport System for astronomical data.

  • Compression: Lossless
  • Transparency: Not supported
  • Animation: Not supported

What Is JXL Format?

JPEG XL format with excellent compression and progressive decoding.

  • Compression: Lossy & Lossless
  • Transparency: Supported
  • Animation: Supported