Reference:File Format

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Accessing GeoGebra files

A GeoGebra file is ending with .ggb (GeoGebra worksheet) or .ggt (GeoGebra tool), which are both just renamed .zip files. You can easily open them with a ZIP program of your choice by renaming them to .zip and open them as you would open any .zip file.


.ggb - GeoGebra Worksheet

The .ggb file is the standard way to save GeoGebra worksheets. As stated above this file is just a renamed .zip file. If you rename your .ggb to .zip you will find the following files after unzipping:


This is the file in which all the information about the construction is stored, the information is stored in XML. For more information about the contents and structure of this file see the XML reference.


This image contains a small preview image of the construction saved in the geogebra.xml. GeoGebra itself uses this image for the preview of GeoGebra files in the "Open.." and "Save As.." Dialog. This thumbnail could also be used to display previews of GeoGebra files within the operating systems file explorer or could be used by online systems or any other kind of software to display previews of uploaded GeoGebra files.


This file contains global JavaScript definitions used in the file. See Scripting for details.


Images used in the construction (included using the GeoGebra Tool Insert Image.gifImage Tool) or as icons of custom tools are not stored with human-readable filenames, but can easily copied and renamed to be extracted out of GeoGebra files. If there are no images or custom tools in the .ggb there will be just the geogebra.xml and geogebra_thumbnail.png in the .ggb.

.ggt - GeoGebra Tool

The .ggt files use the same technique for storage as the .ggb files, so renaming and unzipping will reveal the following files:


This XML stores the main information about the tool. As custom tools are also stored in the normal .ggb files the structure of the entries in this files are also explained in the XML reference.


If there is any special icon assigned to this tool this icon is stored in a sub-folder. Be aware that both the icon and the sub-folder have names not intended to be read by humans, so don't try to make some sense out of it.

Modifying the files

Modifying .ggb or .ggt files (namely the .xml files within them) is clearly a task for the most tech-savvy users of GeoGebra. Whether you want to touch the .xml because you want to modify something which can't be modified by GeoGebra at the moment, like the definition of a custom tool, or you want to trick GeoGebra or just experiment you should take some tips for your journey:

  1. Backup your files. It's almost certain that you will break your files sometime if you're modifying the XML definition.
  2. Read the XML reference to understand what you are doing.
  3. Be aware that the changes you've made may be lost if you re-save your file within GeoGebra. While it might be possible that GeoGebra understands something unusual while loading it might not save it at all or save it somehow anormal which corrupts the file.
  4. ZIP all required files at the end using the most standard ZIP options (no encryption etc.) and rename your files back to .ggb.
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