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Evaluation and Licensing

GemBox.Document works in four different modes:

  • Free mode - free of charge, limited to 20 paragraphs.

  • Trial mode - free of charge, random parts of document text will be replaced with string TRIAL, promotional header will be added to every document page.

  • Time Limited mode - free of charge, limited to 30 days.

  • Professional mode - requires purchasing a license key, no limitations.

All modes use the same GemBox.Document DLL so there is no need to reinstall the component when switching modes.

The first thing to do when coding with GemBox.Document is to instruct the component in which mode it will be used. This is accomplished by calling ComponentInfoSetLicense(String) method with the specific license key parameter:

  • FREE-LIMITED-KEY, to use the component in Free mode.

  • The temporary license key that you receive after sending us a request for Time Limited mode.

  • The professional license key that you receive after purchasing GemBox.Document, to use the component in Professional mode.

Important note Important

ComponentInfo.SetLicense method must be called before using any other class from GemBox.Document component.

Tip Tip

ComponentInfo.SetLicense method can be called multiple times. What is important is that it is called with the same license key.

Ideally, it should be called at the startup of your application. For example, it can be called in a Main method, an application startup event or a static constructor of your main class.


You can evaluate GemBox.Document free of charge and for an unlimited time period, just download the component, install it and use it in Free mode.

Free mode delivers the same performance and set of features as Professional mode, with the following limitations:

If you want to evaluate GemBox.Document performance beyond the first 20 paragraphs, then handle ComponentInfoFreeLimitReached event and set the FreeLimitEventArgsFreeLimitReachedAction to FreeLimitReachedActionContinueAsTrial, as in this following code snippet:

// Set license key to use GemBox.Document in a Free mode.

// Continue to use the component in a Trial mode when free limit is reached.
ComponentInfo.FreeLimitReached += (sender, e) => e.FreeLimitReachedAction = FreeLimitReachedAction.ContinueAsTrial;

// Here goes your application specific code.

This option will enable you to read / write entire document content, with the following limitations imposed after the first 20 paragraphs:

  • When loading a document - random parts of document text will be replaced with string TRIAL.

  • When saving a document - promotional header will be added to every document page and will replace any existing header.


If you have evaluated the component and are satisfied with it, you can purchase the license key to use the component in the Professional mode - without any limitations.

After purchase, the only thing you need to do is to replace FREE-LIMITED-KEY with your purchased license key in ComponentInfoSetLicense(String) method call.

Note Note

There is no other installer or DLL for the Professional mode. You should continue to use the reference to existing GemBox.Document DLL in your project when switching to Professional mode.

Professional mode also includes technical support with prompt bug fixes. For more information, see Technical Support.