What is the RDLC file format?
.rdlc is the client-side variant of Microsoft's Report Definition Language format, an XML-based file used to define the layout, data bindings, and appearance of reports rendered by the ReportViewer control in Windows Forms and ASP.NET WebForms applications.
The key distinction between .rdlc and the closely related .rdl format is how data reaches the report: an .rdl file embeds its own data source connection string and query, while an .rdlc file intentionally omits these - data is supplied programmatically at runtime by the host application via ReportViewer.LocalReport.DataSources. This design lets developers bind any in-memory DataTable or object collection to the report without modifying the report file.
Structurally, an .rdlc file is a standard XML document following the RDL schema (namespace http://schemas.microsoft.com/sqlserver/reporting/20xx/01/reportdefinition). It describes report elements such as tables, matrices, charts, text boxes, images, parameters, and page settings. Multiple schema versions exist (2005, 2008, 2010, 2016), declared in the root xmlns attribute.
.rdlc files are created and edited in Visual Studio using the Report Designer, or in Microsoft Report Builder. At runtime, the ReportViewer control renders them locally; the successor for ASP.NET Core scenarios is Microsoft.Reporting.NETCore.
- Supported export formats include PDF, Excel, Word, CSV, and image formats.
- Reports can be embedded as project resources or loaded from the file system at runtime.
Security & safety
RISK: LOWRDLC is an XML text file; it can contain expressions (Visual Basic .NET syntax) evaluated at render time. Malicious expressions are theoretically possible if loading untrusted RDLC files programmatically, but this is a developer-facing format - end users do not normally open arbitrary RDLC files.
Format details
in a nutshellPrograms that open RDLC files
Windows3 apps
Microsoft Visual Studio
Freemium Double-click the .rdlc file in Solution Explorer - opens the visual report designer. 
Microsoft Report Builder
Free File → Open → browse to .rdlc - full graphical designer, no Visual Studio needed. Technical details
deep spec| Format type | XML text document (RDL schema subset) |
| MIME type | application/octet-stream (no registered MIME; text/xml used informally) |
| Text encoding | UTF-8 (default) or UTF-16 with BOM |
| Typical file size | 5 KB - 500 KB; reports with embedded images can reach several MB |
| XML namespace | http://schemas.microsoft.com/sqlserver/reporting/20xx/01/reportdefinition (version-dependent) |
| Schema versions | 2003, 2005, 2008, 2008r2, 2010, 2016 (declared in root xmlns attribute) |
| Data binding model | Data supplied programmatically at runtime via ReportViewer.LocalReport.DataSources; no embedded connection string or query |
| Runtime engine | ReportViewer control (WinForms / ASP.NET WebForms); Microsoft.Reporting.NETCore for ASP.NET Core |
| Authoring tools | Visual Studio Report Designer, Microsoft Report Builder |
| Export formats | PDF, Excel, Word, CSV, TIFF, and other image formats via rendering extensions |
| Related format | .rdl (server-side SSRS report; includes embedded data source connection string and query) |
| Platform support | Windows (.NET Framework); cross-platform rendering available via Microsoft.Reporting.NETCore (.NET Core / .NET 5+) |
| Released | 2005 (Visual Studio 2005 / ReportViewer controls) |
| Latest version | RDL 2016 schema (SQL Server 2016 / SSRS) |
| Open standard | Yes · royalty-free |
| Specification | learn.microsoft.com |
RDLC conversions
Community Q&A
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