Working with PDF File Metadata in C#

The following code snippet also work with Aspose.PDF.Drawing library.

Get PDF File Information

In order to get file specific information of a PDF file, you first need to get the DocumentInfo object using Info property of the Document object. Once the DocumentInfo object is retrieved, you can get the values of the individual properties. The following code snippet shows you how to get PDF file information.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetPDFFileInformation()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetFileInfo.pdf"))
    {
        // Get document information
        var docInfo = document.Info;

        // Display document information
        Console.WriteLine("Author: {0}", docInfo.Author);
        Console.WriteLine("Creation Date: {0}", docInfo.CreationDate);
        Console.WriteLine("Keywords: {0}", docInfo.Keywords);
        Console.WriteLine("Modify Date: {0}", docInfo.ModDate);
        Console.WriteLine("Subject: {0}", docInfo.Subject);
        Console.WriteLine("Title: {0}", docInfo.Title);
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetPDFFileInformation()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetFileInfo.pdf"))
    {
        // Get document information
        var docInfo = document.Info;
        // Display document information
        Console.WriteLine("Author: {0}", docInfo.Author);
        Console.WriteLine("Creation Date: {0}", docInfo.CreationDate);
        Console.WriteLine("Keywords: {0}", docInfo.Keywords);
        Console.WriteLine("Modify Date: {0}", docInfo.ModDate);
        Console.WriteLine("Subject: {0}", docInfo.Subject);
        Console.WriteLine("Title: {0}", docInfo.Title);
    }
}

Set PDF File Information

Aspose.PDF for .NET allows you to set file-specific information for a PDF, information like author, creation date, subject, and title. To set this information:

1. Create a DocumentInfo object.
2. Set the values of the properties.
3. Save the updated document using the Document class’ Save method.

The following code snippet shows you how to set PDF file information.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetFileInformation()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetFileInfo.pdf"))
    {
        // Specify document information
        var docInfo = new Aspose.Pdf.DocumentInfo(document);

        docInfo.Author = "Aspose";
        docInfo.CreationDate = DateTime.Now;
        docInfo.Keywords = "Aspose.Pdf, DOM, API";
        docInfo.ModDate = DateTime.Now;
        // Specify custom timezone
        docInfo.CreationTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Tokyo Standard Time").GetUtcOffset(docInfo.CreationDate);
        docInfo.Subject = "PDF Information";
        docInfo.Title = "Setting PDF Document Information";
        docInfo.Producer = "Custom producer";
        docInfo.Creator = "Custom creator";

        // Save PDF document
        document.Save(dataDir + "SetFileInfo_out.pdf");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetFileInformation()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetFileInfo.pdf"))
    {
        // Specify document information
        var docInfo = new Aspose.Pdf.DocumentInfo(document);

        docInfo.Author = "Aspose";
        docInfo.CreationDate = DateTime.Now;
        docInfo.Keywords = "Aspose.Pdf, DOM, API";
        docInfo.ModDate = DateTime.Now;
        // Specify custom timezone
        docInfo.CreationTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Tokyo Standard Time").GetUtcOffset(docInfo.CreationDate);
        docInfo.Subject = "PDF Information";
        docInfo.Title = "Setting PDF Document Information";
        docInfo.Producer = "Custom producer";
        docInfo.Creator = "Custom creator";

        // Save PDF document
        document.Save(dataDir + "SetFileInfo_out.pdf");
    }
}

Get XMP Metadata from PDF File

Aspose.PDF allows you to access a PDF file’s XMP metadata. To get a PDF file’s metadata:

1. Create a Document object and open the input PDF file.
2. Get the file’s metadata using the Metadata property.

The following code snippet shows you how to get metadata from the PDF file.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetXMPMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetXMPMetadata.pdf"))
    {
        // Get and display properties
        Console.WriteLine($"Create Date: {document.Metadata["xmp:CreateDate"]}");
        Console.WriteLine($"Nickname: {document.Metadata["xmp:Nickname"]}");
        Console.WriteLine($"Custom Property: {document.Metadata["xmp:CustomProperty"]}");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetXMPMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "GetXMPMetadata.pdf"))
    {
        // Get and display properties
        Console.WriteLine($"Create Date: {document.Metadata["xmp:CreateDate"]}");
        Console.WriteLine($"Nickname: {document.Metadata["xmp:Nickname"]}");
        Console.WriteLine($"Custom Property: {document.Metadata["xmp:CustomProperty"]}");
    }
}

Set XMP Metadata in a PDF File

Aspose.PDF allows you to set metadata in a PDF file. To set metadata:

1. Create a Document object.
2. Set metadata values using the Metadata property.
3. Save the updated document using the Save method of the Document object.

The following code snippet shows you how to set metadata in a PDF file.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetXMPMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Set properties
        document.Metadata["xmp:CreateDate"] = DateTime.Now.ToString("o");
        document.Metadata["xmp:Nickname"] = "Nickname";
        document.Metadata["xmp:CustomProperty"] = "Custom Value";

        // Save PDF document
        document.Save(dataDir + "SetXMPMetadata_out.pdf");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetXMPMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Set properties
        document.Metadata["xmp:CreateDate"] = DateTime.Now.ToString("o");
        document.Metadata["xmp:Nickname"] = "Nickname";
        document.Metadata["xmp:CustomProperty"] = "Custom Value";

        // Save PDF document
        document.Save(dataDir + "SetXMPMetadata_out.pdf");
    }
}

Insert Metadata with Prefix

Some developers need to create a new metadata namespace with a prefix. The following code snippet shows how to insert metadata with prefix.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPrefixMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Register a namespace URI for the 'xmp' prefix
        document.Metadata.RegisterNamespaceUri("xmp", "http://ns.adobe.com/xap/1.0/");

        // Set the metadata property using the registered prefix
        document.Metadata["xmp:ModifyDate"] = DateTime.Now.ToString("o"); // ISO 8601 format for datetime

        // Save PDF document
        document.Save(dataDir + "SetPrefixMetadata_out.pdf");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPrefixMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SetXMPMetadata.pdf"))
    {
        // Register a namespace URI for the 'xmp' prefix
        document.Metadata.RegisterNamespaceUri("xmp", "http://ns.adobe.com/xap/1.0/");

        // Set the metadata property using the registered prefix
        document.Metadata["xmp:ModifyDate"] = DateTime.Now.ToString("o"); // ISO 8601 format for datetime

        // Save PDF document
        document.Save(dataDir + "SetPrefixMetadata_out.pdf");
    }
}

Working with PDF 2.0 Metadata

Starting from version 22.11, Aspose.PDF supports saving documents as PDF 2.0. According to the PDF 2.0 specification, certain fields in the Info Dictionary are deprecated:

• Title
• Author
• Creator
• Producer
• Subject
• Keywords

Only CreationDate and ModDate remain in the Info Dictionary for PDF 2.0 documents. All deprecated fields are automatically stored in XMP metadata using the xmp: prefix.

Aspose.PDF provides a unified API for working with metadata. You can use the familiar DocumentInfo class to set metadata properties, and the library will automatically handle the storage location based on the PDF version:

• PDF 1.x: Metadata is stored in the Info Dictionary
• PDF 2.0: Deprecated fields (Title, Author, Creator, Producer, Subject, Keywords) are automatically transferred to XMP metadata, while only CreationDate and ModDate remain in the Info Dictionary

This means you can continue using the same code for setting metadata regardless of the target PDF version.

Set Metadata in PDF 2.0 Using DocumentInfo (Unified API)

The unified API allows you to use the familiar DocumentInfo class to set metadata. When saving as PDF 2.0, the deprecated fields are automatically transferred to XMP metadata.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPdf20MetadataUnifiedApi()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf"))
    {
        // Use DocumentInfo to set metadata - works for both PDF 1.x and PDF 2.0
        var documentInfo = document.Info;
        documentInfo.Producer = "My Producer";
        documentInfo.Creator = "My Creator";
        documentInfo.Title = "My Title";
        documentInfo.Author = "My Author";
        documentInfo.Subject = "My Subject";
        documentInfo.Keywords = "keyword1, keyword2, keyword3";

        // Save as PDF 2.0 - deprecated fields will be stored in XMP metadata
        document.Save(dataDir + "Pdf20Metadata_out.pdf");
    }

    // Verify the saved PDF 2.0 document
    using (var checkDoc = new Aspose.Pdf.Document(dataDir + "Pdf20Metadata_out.pdf"))
    {
        // For PDF 2.0, Info Dictionary contains only CreationDate and ModDate
        var info = checkDoc.Info;
        Console.WriteLine($"Info Dictionary keys: {info.Keys.Count}");

        // Access metadata from XMP for PDF 2.0
        var metadata = checkDoc.Metadata;
        Console.WriteLine($"Title from XMP: {metadata["xmp:Title"]}");
        Console.WriteLine($"Author from XMP: {metadata["xmp:Author"]}");
        Console.WriteLine($"Subject from XMP: {metadata["xmp:Subject"]}");
        Console.WriteLine($"Keywords from XMP: {metadata["xmp:Keywords"]}");
        Console.WriteLine($"Creator from XMP: {metadata["xmp:Creator"]}");
        Console.WriteLine($"Producer from XMP: {metadata["xmp:Producer"]}");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPdf20MetadataUnifiedApi()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf");

    // Use DocumentInfo to set metadata - works for both PDF 1.x and PDF 2.0
    var documentInfo = document.Info;
    documentInfo.Producer = "My Producer";
    documentInfo.Creator = "My Creator";
    documentInfo.Title = "My Title";
    documentInfo.Author = "My Author";
    documentInfo.Subject = "My Subject";
    documentInfo.Keywords = "keyword1, keyword2, keyword3";

    // Save as PDF 2.0 - deprecated fields will be stored in XMP metadata
    document.Save(dataDir + "Pdf20Metadata_out.pdf");

    // Verify the saved PDF 2.0 document
    using var checkDoc = new Aspose.Pdf.Document(dataDir + "Pdf20Metadata_out.pdf");

    // For PDF 2.0, Info Dictionary contains only CreationDate and ModDate
    var info = checkDoc.Info;
    Console.WriteLine($"Info Dictionary keys: {info.Keys.Count}");

    // Access metadata from XMP for PDF 2.0
    var metadata = checkDoc.Metadata;
    Console.WriteLine($"Title from XMP: {metadata["xmp:Title"]}");
    Console.WriteLine($"Author from XMP: {metadata["xmp:Author"]}");
    Console.WriteLine($"Subject from XMP: {metadata["xmp:Subject"]}");
    Console.WriteLine($"Keywords from XMP: {metadata["xmp:Keywords"]}");
    Console.WriteLine($"Creator from XMP: {metadata["xmp:Creator"]}");
    Console.WriteLine($"Producer from XMP: {metadata["xmp:Producer"]}");
}

Get Metadata from PDF 2.0 Using XMP

For PDF 2.0 documents, you can directly access metadata using the Metadata property with the xmp: prefix.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetPdf20Metadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF 2.0 document
    using (var document = new Aspose.Pdf.Document(dataDir + "Pdf20Document.pdf"))
    {
        var metadata = document.Metadata;

        // Get standard metadata fields from XMP
        var title = metadata["xmp:Title"]?.ToString();
        var author = metadata["xmp:Author"]?.ToString();
        var subject = metadata["xmp:Subject"]?.ToString();
        var keywords = metadata["xmp:Keywords"]?.ToString();
        var creator = metadata["xmp:Creator"]?.ToString();
        var producer = metadata["xmp:Producer"]?.ToString();

        Console.WriteLine($"Title: {title}");
        Console.WriteLine($"Author: {author}");
        Console.WriteLine($"Subject: {subject}");
        Console.WriteLine($"Keywords: {keywords}");
        Console.WriteLine($"Creator: {creator}");
        Console.WriteLine($"Producer: {producer}");

        // You can also access custom metadata
        if (metadata.ContainsKey("xmp:CustomKey"))
        {
            var customValue = metadata["xmp:CustomKey"]?.ToString();
            Console.WriteLine($"Custom Key: {customValue}");
        }
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetPdf20Metadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF 2.0 document
    using var document = new Aspose.Pdf.Document(dataDir + "Pdf20Document.pdf");

    var metadata = document.Metadata;

    // Get standard metadata fields from XMP
    var title = metadata["xmp:Title"]?.ToString();
    var author = metadata["xmp:Author"]?.ToString();
    var subject = metadata["xmp:Subject"]?.ToString();
    var keywords = metadata["xmp:Keywords"]?.ToString();
    var creator = metadata["xmp:Creator"]?.ToString();
    var producer = metadata["xmp:Producer"]?.ToString();

    Console.WriteLine($"Title: {title}");
    Console.WriteLine($"Author: {author}");
    Console.WriteLine($"Subject: {subject}");
    Console.WriteLine($"Keywords: {keywords}");
    Console.WriteLine($"Creator: {creator}");
    Console.WriteLine($"Producer: {producer}");

    // You can also access custom metadata
    if (metadata.ContainsKey("xmp:CustomKey"))
    {
        var customValue = metadata["xmp:CustomKey"]?.ToString();
        Console.WriteLine($"Custom Key: {customValue}");
    }
}

Set Metadata in PDF 2.0 Using XMP Directly

You can also set metadata directly using the Metadata property with XmpValue objects.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPdf20MetadataDirectly()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf"))
    {
        // Set metadata directly using XMP
        document.Metadata["xmp:Producer"] = new Aspose.Pdf.XmpValue("My Producer");
        document.Metadata["xmp:Creator"] = new Aspose.Pdf.XmpValue("My Creator");
        document.Metadata["xmp:Title"] = new Aspose.Pdf.XmpValue("Document Title");
        document.Metadata["xmp:Author"] = new Aspose.Pdf.XmpValue("John Doe");
        document.Metadata["xmp:Subject"] = new Aspose.Pdf.XmpValue("PDF 2.0 Metadata Example");
        document.Metadata["xmp:Keywords"] = new Aspose.Pdf.XmpValue("PDF, metadata, XMP, PDF 2.0");

        // Set custom metadata
        document.Metadata["xmp:CustomProperty"] = new Aspose.Pdf.XmpValue("Custom Value");

        // Save PDF document
        document.Save(dataDir + "Pdf20XmpMetadata_out.pdf");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void SetPdf20MetadataDirectly()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF document
    using var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf");

    // Set metadata directly using XMP
    document.Metadata["xmp:Producer"] = new Aspose.Pdf.XmpValue("My Producer");
    document.Metadata["xmp:Creator"] = new Aspose.Pdf.XmpValue("My Creator");
    document.Metadata["xmp:Title"] = new Aspose.Pdf.XmpValue("Document Title");
    document.Metadata["xmp:Author"] = new Aspose.Pdf.XmpValue("John Doe");
    document.Metadata["xmp:Subject"] = new Aspose.Pdf.XmpValue("PDF 2.0 Metadata Example");
    document.Metadata["xmp:Keywords"] = new Aspose.Pdf.XmpValue("PDF, metadata, XMP, PDF 2.0");

    // Set custom metadata
    document.Metadata["xmp:CustomProperty"] = new Aspose.Pdf.XmpValue("Custom Value");

    // Save PDF document
    document.Save(dataDir + "Pdf20XmpMetadata_out.pdf");
}

Convert PDF 1.x to PDF 2.0 with Metadata

You can convert an existing PDF 1.x document to PDF 2.0 format while setting metadata. During conversion, the deprecated Info Dictionary fields will be automatically transferred to XMP metadata.

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ConvertToPdf20WithMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF 1.x document
    using (var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf"))
    {
        // Set metadata using DocumentInfo
        document.Info.Title = "Document Title";
        document.Info.Author = "John Doe";
        document.Info.Subject = "PDF 2.0 Conversion Example";
        document.Info.Keywords = "PDF, conversion, PDF 2.0, metadata";
        document.Info.Creator = "My Application";
        document.Info.Producer = "Aspose.PDF";

        // Add custom metadata
        document.Info.Add("CustomKey", "CustomValue");

        // Convert to PDF 2.0 format
        var conversionOptions = new Aspose.Pdf.PdfFormatConversionOptions(
            dataDir + "ConversionLog.xml",
            Aspose.Pdf.PdfFormat.v_2_0);
        document.Convert(conversionOptions);

        // Save the PDF 2.0 document
        document.Save(dataDir + "ConvertedToPdf20_out.pdf");
    }

    // Verify the converted document
    using (var checkDoc = new Aspose.Pdf.Document(dataDir + "ConvertedToPdf20_out.pdf"))
    {
        // For PDF 2.0, deprecated fields are stored in XMP metadata
        var metadata = checkDoc.Metadata;
        Console.WriteLine($"Title from XMP: {metadata["xmp:Title"]}");
        Console.WriteLine($"Author from XMP: {metadata["xmp:Author"]}");
        Console.WriteLine($"Subject from XMP: {metadata["xmp:Subject"]}");
        Console.WriteLine($"Keywords from XMP: {metadata["xmp:Keywords"]}");

        // Custom metadata is also available in XMP
        if (metadata.ContainsKey("xmp:CustomKey"))
        {
            Console.WriteLine($"Custom Key from XMP: {metadata["xmp:CustomKey"]}");
        }
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void ConvertToPdf20WithMetadata()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_WorkingDocuments();

    // Open PDF 1.x document
    using var document = new Aspose.Pdf.Document(dataDir + "Sample.pdf");

    // Set metadata using DocumentInfo
    document.Info.Title = "Document Title";
    document.Info.Author = "John Doe";
    document.Info.Subject = "PDF 2.0 Conversion Example";
    document.Info.Keywords = "PDF, conversion, PDF 2.0, metadata";
    document.Info.Creator = "My Application";
    document.Info.Producer = "Aspose.PDF";

    // Add custom metadata
    document.Info.Add("CustomKey", "CustomValue");

    // Convert to PDF 2.0 format
    var conversionOptions = new Aspose.Pdf.PdfFormatConversionOptions(
        dataDir + "ConversionLog.xml",
        Aspose.Pdf.PdfFormat.v_2_0);
    document.Convert(conversionOptions);

    // Save the PDF 2.0 document
    document.Save(dataDir + "ConvertedToPdf20_out.pdf");

    // Verify the converted document
    using var checkDoc = new Aspose.Pdf.Document(dataDir + "ConvertedToPdf20_out.pdf");

    // For PDF 2.0, deprecated fields are stored in XMP metadata
    var metadata = checkDoc.Metadata;
    Console.WriteLine($"Title from XMP: {metadata["xmp:Title"]}");
    Console.WriteLine($"Author from XMP: {metadata["xmp:Author"]}");
    Console.WriteLine($"Subject from XMP: {metadata["xmp:Subject"]}");
    Console.WriteLine($"Keywords from XMP: {metadata["xmp:Keywords"]}");

    // Custom metadata is also available in XMP
    if (metadata.ContainsKey("xmp:CustomKey"))
    {
        Console.WriteLine($"Custom Key from XMP: {metadata["xmp:CustomKey"]}");
    }
}