JXL vs FTS — Comparison & Free Converter
Fast, instant JPEG XL to FTS conversion. No signup required. Just drop your .jxl file and get .fts in seconds.
Batch Settings
您是否曾遇到这样的情况：手头是一张色彩鲜艳、细节丰富的JXL图片，却在分享到微信群、或是准备导入某些特定软件时犯了难？JXL（JPEG XL）作为一种新兴的图片格式，在压缩效率和画质表现上都非常出色，但其普及度在某些应用场景，特别是国内移动生态和特定专业领域，仍有待提升。FTS（或常说的FITS）格式，作为天文学、科学图像处理领域的标准，虽然听起来与日常图片处理相去甚远，但在某些专业工作流中却是不可或缺的。本工具致力于为您提供一个流畅、高效的JXL到FTS转换方案，让您的图像资产能在不同平台间无缝流转，无论是科研数据处理，还是特殊项目需求，都能轻松应对。
- 天文图像数据处理
- 专业科学图片归档
- 特定软件兼容性需求
值得注意的是，JXL格式在大陆地区的应用，目前主要集中在部分前沿浏览器和特定图片编辑软件中，而FTS格式则更常见于科研院所。在微信等主流社交平台直接分享JXL图片，目前仍可能面临兼容性问题。
About JPEG XL to FTS Conversion
JXL or FTS — which format should you use? The answer depends on your needs. Here's a quick breakdown.
JPEG XL is a next-generation format with both lossless and lossy modes, aiming to replace JPEG and PNG. It has niche platform support. FTS is a widely used file format. It has common platform support.
So when should you convert JXL to FTS? This conversion is ideal when you When you need a FTS file. This conversion helps you convert between formats quickly.
Converting JXL to FTS maintains high quality with CocoConvert's optimised encoder settings.
If you've decided FTS is the right choice, CocoConvert makes the conversion effortless. Upload your .jxl file, pick FTS, and click Convert — done in seconds. The converter runs on secure servers in Germany, powered by FFmpeg, Sharp, and qpdf. Files are encrypted via TLS and erased within 24 hours.
Free tier: 5 files/hour, 250 MB each. Pro: 100 files/hour, 5 GB each. Works in every modern browser on desktop and mobile.
How to Convert JPEG XL to FTS
- 1
Choose your JXL file
Upload your .jxl file using drag-and-drop or the file browser. Batch mode lets you add multiple files.
- 2
Set format to FTS
Select .fts from the output options. The converter applies optimal quality settings automatically.
- 3
Run the conversion
Click Convert. Server-side processing means your device stays fast — even for large image files.
- 4
Get your FTS file
Download your converted file instantly. Batch downloads are available as a zip archive.
What Happens When You Convert JPEG XL to FTS
Your JXL file is decoded and re-encoded as FTS.
Your JXL file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in FTS format
The converted file is ready for download
Format Comparison
JPEG XL
.jxl file
| Extension | .jxl |
| MIME Type | image/jxl |
| Category | Image |
FTS
.fts file
| Extension | .fts |
| MIME Type | image/fits |
| Category | Image |
Should You Convert JPEG XL to FTS?
When to Convert
- ✓When you need a FTS file
Frequently Asked Questions
Should I use JXL or FTS?
It depends on your goal. JXL preserves full quality. FTS preserves full quality. Choose based on whether file size or quality matters more for your use case.
Is FTS higher quality than JXL?
Not necessarily. Converting JXL to FTS maintains high quality with CocoConvert's optimised encoder settings. Quality depends on the compression type and settings, not just the format name.
Can I convert JXL to FTS on Mac and Windows?
Yes. CocoConvert is a web-based tool that works in all modern browsers — Chrome, Safari, Firefox, Edge — on any operating system including macOS, Windows, Linux, iOS, and Android.
Is CocoConvert free for JXL to FTS?
Yes. Free users get 5 conversions per hour (250 MB each). Pro subscribers unlock 100 files per hour, 5 GB per file, and priority processing.
What tools does CocoConvert use for JXL to FTS?
CocoConvert uses FFmpeg for audio/video, Sharp for images, and qpdf for documents — the same open-source libraries used by Netflix, YouTube, and major enterprise platforms.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.