Convert TNL to FITS

Convert TNL to FITS without quality loss. reaConverter gives you full control over resolution, compression, and output settings.

Batch TNL to FITS conversion doesn't have to be complicated. reaConverter processes entire folders with consistent quality settings. Works offline with no internet required — convert anywhere, anytime.

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TNL to FITS
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How to Convert Multiple TNL Files to FITS?

1. Download and Install reaConverter

reaConverter installs quickly on any Windows PC. No dependencies, no bloatware — just a clean setup that's ready to use immediately.

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Install reaConverter

2. Load your TNL files

Load your TNL files into reaConverter. You can add individual files or point to folders, and the software will queue everything automatically.

Select TNLs from a folder or drag-and-drop them directly into the reaConverter window.

Load your TNL files into reaConverter

3. Select FITS as output format

Choose FITS for output and set your save location. reaConverter lets you customize quality and apply edits before conversion.

Select FITS as output format

4. Start TNL to FITS conversion

Press the Convert button and reaConverter takes care of the rest. Processing time depends on file size and volume.

Start Conversion

After processing, find all your new .fits files in the output location. The log shows details for each conversion.

TNL to FITS Converter

reaConverter offers the fastest, simplest solution for converting your TNL files into FITS in seconds - all files processed on your PC for maximum privacy and speed.

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Do more with your files

Converting TNL files for use in a workflow? reaConverter offers many ways to process files, so you can customize them according to your requirements.

Our range of editing options includes auto-processing options such as auto-rotate, auto-crop, watermarking and more. Change Color Space, copy Metadata, set DPI, manage ICC Profile, control Bit Depth.

Conversion features
Image editing

User Reviews

Average User Rating:
Last updated on January 19, 2026
"Essential for our astroimaging pipeline! reaConverter perfectly handles FITS files from our research telescope, preserving all WCS coordinates and photometric data during batch conversion to TIFF. Now we process 100+ deep-sky exposures nightly without losing critical metadata for our exoplanet studies!"
Joseph Wilson
Joseph Wilson
Satisfied Customer
"reaConverter makes FITS conversion incredibly easy. We batch convert astronomical images to standard formats for presentations and analysis, all automated through the command-line. It’s fast, reliable, and handles large datasets without issues."
Laura N.
Laura N.
Astrophysics Research Assistant
"This software just works! My old laptop can’t handle Photoshop, but reaConverter flies through conversions without breaking a sweat. Wi-Fi gone? Still strong!"
Robert Williams
Robert Williams
Happy User
"Rare software that actually does it all! Converts anything, beautiful interface, and never lets me down. A must-have!"
Henry R.
Henry R.
Happy User
"For cross-platform compatibility, JPEG remains the gold standard. reaConverter’s precision conversions ensure perfect results every time, whether for presentations, websites, or client deliverables."
Paul Baker
Paul Baker
Happy User
"An ultra-fast solution for minimizing file sizes. The entire conversion process takes just 3 minutes!"
Logan B.
Logan B.
Satisfied Customer

TNL to FITS Conversion: FAQ

What are TNL files?

TNL is an obsolete image format storing thumbnail images. It is considered rare and probably difficult to open using regular image viewers. Conversion to more popular formats might be the best way to access TNL files.

What are FITS files?

The FITS (Flexible Image Transport System) format is a standard format used particularly for storing, transferring and processing scientific images from fields such as astronomy. FITS was first launched as an open standard in the early 1980s and has gone through several subsequent upgrades. FITS files contain not just images, but also data related to photometry and spatial calibration, and information about the origin of the image. Similar formats include FIT and FTS.

Can reaConverter convert TNL to FITS?

Yes! reaConverter instantly converts .tnl to .fits with perfect quality preservation. With its batch processing feature, you can convert multiple files at once in just a few clicks. You can even convert images directly from Windows Explorer using the right-click menu — fast and convenient.

Can I convert TNL to FITS online?

If you only need to convert a few TNL files to FITS format, feel free to try our free online free online TNL to FITS converter — perfect for small batches with no installation needed!

How can I turn TNL files into FITS on my computer?

The best way to change TNLs to FITSs on your PC is to install a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from TNL to FITS.

How can I automate TNL to FITS files conversion?

reaConverter supports all the most useful automation features such as right-click сonversion and Watch Folders for the most efficient automated files conversion in any software of this type.

Is there a way to convert TNL files to FITS using the command prompt?

reaConverter provides full access to all its features via Windows command line, including a high-performance command-line tnl to fits converter for batch processing.

What else can I do with reaConverter?

Change format settingsChange DPIConvert DICOM filesChange photo sizeConvert GIS files

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