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GTM Converter

GTM to any format, in batch and offline. reaConverter gives you full control over quality and output settings.

GTMConverter
4.8

Over 25 years of experience

Your files never leave your PC

Read what our users say →

How to Convert .gtm Files in Bulk

1. Install reaConverter

Download reliable GTM conversion software to convert multiple .gtm files and folders in one go.

2. Select GTM Files

Select GTMs from a folder or drag and drop them into reaConverter, then choose the desired output format.
reaConverter - Load GTM files

3. Start Conversion

Click Convert to start the bulk conversion of all selected GTM files. The process will begin right away.
reaConverter - Start GTM conversion

Step by step

See It in Action

For quick and effortless GTM file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.

GIS Toolkit

Do more with your GIS data

Need GTM data as something anyone can open? reaConverter renders imagery and elevation grids into standard images and documents without QGIS or ArcGIS, and works through whole folders in one pass.

  • Render imagery, elevation grids and scanned charts to TIFF, PNG, JPG or PDF
  • Resize, crop and set DPI on the output in the same run
  • Bring tiles, scenes and grids from many sources into one consistent format
  • Convert incoming survey and field data automatically with Watch Folders
  • Script GIS conversions from the command line for pipelines and scheduled jobs
  • Keep cadastral, utility and client data on your PC: nothing is uploaded
GIS data conversion

User reviews

From those who tried it

Average User Rating:
Last updated on July 30, 2026
We deployed reaConverter across our department to standardize file formats for our archives. The command-line support and automation features integrated perfectly into our systems. Stellar performance and zero crashes—it just works.
David R.
David R.
IT Solutions Architect
Enable shell integration for lightning-fast file conversions directly from Windows Explorer.
R. Lewis
R. Lewis
Happy User
Tried a few image tools before, but this one is by far the easiest. Drag, drop, convert — done in seconds. It saved me a ton of time when organizing my image folders.
Lisa K.
Lisa K.
Happy User
Before reaConverter, I was the ‘File Conversion Guy’ at work — a title I never asked for and definitely didn’t want. Then I found the Watch Folders feature, and suddenly I was free! Now, files convert themselves while I sip coffee and pretend I'm still working hard. My coworkers think I'm a wizard. Thanks reaConverter, for saving my sanity and boosting my fake productivity!
Ben H.
Ben H.
Overwhelmed Office Hero
This program is incredibly simple and user-friendly, even beginners can use it with ease. It supports batch processing, works offline, and runs smoothly on my aging Acer Aspire laptop. Best of all, the output quality is outstanding!
Kevin Harris
Kevin Harris
Happy User
Your solution was buried deeper in search results than it should be. After struggling with unclear alternatives, I found your guides — finally, instructions that made sense for a first-time user like me. Excellent work!
Richard E. Miller
Richard E. Miller
Satisfied Customer

Questions & Answers

GTM files: Frequently Asked Questions

Can reaConverter open GTM files?

reaConverter fully supports the GTM file format – open, edit, and export GTM files to any other popular file format with ease.

Do I need QGIS or ArcGIS to convert GTM files?

No. reaConverter reads GTM files on its own, so the conversion needs no GIS installation and no licence. It handles whole folders at once, which suits survey archives, tile sets and data deliveries that have to reach people working in other software.

How do I change GTM to another format?

reaConverter is a user-friendly tool for converting GTM files. Once installed on your computer, it allows you to convert all your .gtm files at once with just a few clicks. You can even convert GTM files directly from Windows Explorer using the right-click menu — fast and convenient.

Why choose offline conversion with reaConverter?

Keep your sensitive data 100% private with offline processing that never exposes files to cloud risks. Our software meets strict compliance standards (GDPR, HIPAA, CCPA) while handling confidential documents for legal, healthcare and financial sectors.

Can I convert GTM online?

If you only want to convert a few GTM files, you are welcome to try our free online GTM converter.

How can I turn GTM files on my computer to another format?

The best way to convert GTM files on your PC is to get 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 GTM.

How can I automate GTM files conversion?

reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.

Can I convert GTM files using scripts or the command-line interface?

reaConverter provides full access to all its features from the Windows command-line shell, including the command-line gtm converter.

What else can I do with reaConverter?

Convert RAW formatsConvert DICOM imagesCrop photoConvert microscopy filesPicture resizer

What formats can I convert a GTM file to?

Discover More

Beyond GTM conversion

Convert .gtm files in batches of any size, with editing and processing applied along the way. The same tool also handles 800+ other formats, including CAD, medical imaging, and GIS.

Free trial · Windows 10/11 · v8.0.251 · Files never leave your computer

reaConverter software