Guide
How to update PDF metadata in C#
Call GetMetadataAsync(), update the fields you care about, and save the document.
The editable fields are Title, Author, Subject,
Keywords, Creator, and CreationDate. ZingPDF stamps
Producer and refreshes ModifiedDate during save.
The shortest working example
Load the metadata wrapper, set the values you want, then save.
using ZingPDF;
using var pdf = Pdf.Load(File.OpenRead("input.pdf"));
using var output = File.Create("metadata-updated.pdf");
var metadata = await pdf.GetMetadataAsync();
metadata.Title = "Quarterly Report";
metadata.Author = "Taylor Smith";
metadata.Subject = "Financial summary";
metadata.Keywords = "finance,quarterly";
metadata.Creator = "Back Office Importer";
metadata.CreationDate = new DateTimeOffset(2026, 3, 1, 9, 0, 0, TimeSpan.Zero);
await pdf.SaveAsync(output);Editable fields
The high-level metadata wrapper gives you direct access to the common document info values.
TitleAuthorSubjectKeywordsCreatorCreationDate
If the file does not already have an info dictionary, ZingPDF creates one during save.
Fields managed during save
Producer is stamped to ZingPDF and ModifiedDate is refreshed when
you save the document.
That means you should treat those values as save-managed output rather than values you set manually through the high-level wrapper.
Need the document text too?
Metadata updates and text extraction often sit in the same ingestion path.