# Licensing > Apply, manage, and troubleshoot licenses in Aspose.Slides for C++. Ensure uninterrupted access to full features with our step-by-step licensing guide. Source: https://docs.aspose.com/slides/cpp/licensing/ Updated: 2026-08-13 ## **Overview** Aspose.Slides can be used in evaluation mode or with a valid license. The evaluation version provides the same functionality as the licensed version, but it adds an evaluation watermark when presentations are opened or saved and limits text extraction to one slide. This article explains how licensing works in Aspose.Slides and how to apply a license before using the library. A license can be loaded from a file, stream, or embedded resource by using the `License` class. The article also shows how to validate whether a license has been applied correctly. ## **Evaluate Aspose.Slides** {{% alert color="info" %}} You can download an evaluation version of **Aspose.Slides for C++** from [its NuGet download page](https://www.nuget.org/packages/Aspose.Slides.CPP/). The evaluation version offers the same functionality as the licensed product. In fact, the evaluation package is identical to the purchased one—it simply becomes licensed once you add a few lines of code to apply the license. Once you're satisfied with your evaluation of **Aspose.Slides**, you can [purchase a license](https://purchase.aspose.com/buy). We recommend reviewing the available subscription types. If you have any questions, feel free to contact the Aspose sales team. Every Aspose license includes a one-year subscription for free upgrades, including new versions and bug fixes released during that period. Whether you're using a licensed or evaluation version, you receive free and unlimited technical support. {{% /alert %}} **Evaluation Version Limitations** * While the Aspose.Slides evaluation version (when no license is applied) provides full product functionality, it inserts an evaluation watermark at the top of the document during open and save operations. * Text extraction is limited to one slide when using the evaluation version. {{% alert color="info" %}} To test Aspose.Slides without limitations, you can request a **30-Day Temporary License**. For more information, see the [How to Get a Temporary License](https://purchase.aspose.com/temporary-license) page. {{% /alert %}} ## **Licensing in Aspose.Slides** * An evaluation version becomes licensed after you purchase a license and apply it by adding a couple of lines of code. * The license is a plain-text XML file that contains details such as the product name, the number of developers it is licensed to, the subscription expiry date, and more. * The license file is digitally signed, so it must not be modified. Even an accidental change—such as adding a line break—will invalidate the file. * Aspose.Slides for C++ typically looks for the license file in the following locations: * A path explicitly specified in your code * The folder containing the component’s DLL (included in Aspose.Slides) * The folder containing the assembly that calls the component’s DLL * To avoid the limitations of the evaluation version, you must set the license before using Aspose.Slides. A license only needs to be set once per application or process. ## **Apply a License** A license can be loaded from a **file**, a **stream**, or an **embedded resource**. {{% alert color="info" %}} Aspose.Slides provides the [License](https://reference.aspose.com/slides/cpp/class/aspose.slides.license/) class for licensing operations. {{% /alert %}} {{% alert color="warning" %}} New licenses can activate Aspose.Slides only with version 21.4 or later. Earlier versions use a different licensing system and will not recognize these licenses. {{% /alert %}} ### **File** The easiest way to set a license is to place the license file in the same folder as the component’s DLL (included in Aspose.Slides) and specify only the file name, without the path. The following C++ code shows how to set a license file: ```c++ #include #include #include using namespace Aspose::Slides; using namespace System; int main() { auto license = MakeObject(); license->SetLicense(u"Aspose.Slides.lic"); return 0; } ``` {{% alert color="warning" %}} If you place the license file in a different directory, then when calling the [License::SetLicense](https://reference.aspose.com/slides/cpp/aspose.slides/license/setlicense/) method, the file name at the end of the specified explicit path must exactly match the name of your license file. For example, if you rename your license file to *Aspose.Slides.lic.xml*, you must pass the full path ending with *Aspose.Slides.lic.xml* to the [License::SetLicense](https://reference.aspose.com/slides/cpp/aspose.slides/license/setlicense/) method in your code. {{% /alert %}} ### **Stream** You can load a license from a stream. The following C++ code shows how to apply a license from a stream: ```c++ #include #include #include using namespace Aspose::Slides; using namespace System; using namespace System::IO; auto license = MakeObject(); auto stream = File::OpenRead(u"Aspose.Slides.lic"); license->SetLicense(stream); ``` ## **Validate a License** To check whether a license has been set properly, you can validate it. The following C++ code shows how to validate a license: ```c++ #include #include using namespace Aspose::Slides; using namespace System; auto license = MakeObject(); license->SetLicense(u"Aspose.Slides.lic"); if (license->IsLicensed()) { Console::WriteLine(u"License is good!"); Console::ReadKey(); } ``` ## **Thread Safety** {{% alert title="Note" color="warning" %}} The [License::SetLicense](https://reference.aspose.com/slides/cpp/aspose.slides/license/setlicense/) method is **not thread-safe**. If you need to call this method from multiple threads simultaneously, it's recommended to use synchronization primitives (such as a lock) to prevent potential issues. {{% /alert %}} ## **FAQ** ### Can I apply the license in a completely offline environment (no internet access)? Yes. License validation is performed locally using the license file; no internet connection is required. ### What happens after the one-year subscription expires? Will the library stop working? No. The license is perpetual: you can continue using versions released before your subscription end date; you just won’t be eligible to use newer releases without renewing. ## Related articles - [Evaluate Aspose.Slides](https://docs.aspose.com/slides/cpp/evaluate-aspose-slides/)