By properly implementing your IronPDF license key, you ensure a seamless, professional experience for both your development team and your end-users, backed by the full power of a premium PDF engine.

You have exceeded the number of allowed developers or machines. A Single Developer license allows one named developer but unlimited deploys to servers. However, simultaneous usage from multiple developer machines triggers this.

| Error Message | Likely Cause | Solution | |---------------|--------------|----------| | “License key not found” | Key not set before first PDF operation | Set LicenseKey on app start | | “Evaluation only” | Trial expired or missing key | Add valid key | | “Invalid license key” | Typo or wrong format | Double-check dashes & prefix | | “License mismatch” | Key for different product | IronPDF keys start with IRONPDF- |

But without a key:

Integrating the license key into a project is designed to be a seamless process for developers. The key is typically applied globally within the application startup code before any IronPDF objects are instantiated. For example, in a C# .NET environment, the key is passed to the License.LicenseKey property. This single line of code activates the library across the application. It is crucial to manage these keys securely; best practices suggest storing the key in configuration files (like appsettings.json or web.config ) or secure environment variables rather than hard-coding them directly into source control repositories. This approach prevents unauthorized distribution of the license and maintains security hygiene.

An IronPDF license key is a unique string used to authenticate the library for and remove watermarks from generated documents . While the library is free to download and use for local development and testing, a license key is required to move into a live production environment . 🔑 Key License Tiers