---
title: "Sanitize PDF documents in C# | Nutrient .NET SDK"
canonical_url: "https://www.nutrient.io/guides/dotnet/security/sanitize-pdf/"
md_url: "https://www.nutrient.io/guides/dotnet/security/sanitize-pdf.md"
last_updated: "2026-09-22T00:00:00.000Z"
description: "Learn how to remove hidden, private, or non-visible data from PDFs using Nutrient .NET SDK."
---

# Sanitize PDF documents in C#

PDF sanitization removes hidden, private, or non-visible data from a PDF. Use it before sharing documents outside your organization or before archiving documents that shouldn't retain metadata or embedded objects.

Nutrient.NET SDK sanitizes selected categories, such as metadata, annotations, form fields, attachments, scripts, image metadata, tags, layers, and other hidden data.

This guide shows how to:

- Load a PDF

- Sanitize all supported hidden-data categories

- Save the sanitized PDF

- Read the JSON sanitization report

## Prepare the project

Register the SDK license before running PDF operations. For setup details, refer to the [getting started with.NET SDK](https://www.nutrient.io/sdk/dotnet/getting-started.md) guide.

```csharp

using System;
using System.IO;
using GdPicture14;

void CheckStatus(GdPictureStatus status, string operation)
{
    if (status!= GdPictureStatus.OK)
    {
        throw new InvalidOperationException($"{operation} failed. Status: {status}");
    }
}

LicenseManager license = new LicenseManager();
license.RegisterKEY(""); // Set your license key

```

## Load the PDF document

Create a `GdPicturePDF` instance and load the source file:

```csharp

using GdPicturePDF pdf = new GdPicturePDF();

CheckStatus(pdf.LoadFromFile(@"input.pdf", false), "LoadFromFile");

```

## Sanitize the PDF

Run the sanitization pass and request a JSON report:

```csharp

string reportJson = "";
CheckStatus(pdf.Sanitize(SanitizeCategories.All, ref reportJson), "Sanitize");

```

`SanitizeCategories.All` removes every supported category. To remove specific data types, combine flags. For example, use `SanitizeCategories.Metadata | SanitizeCategories.Scripts` to remove metadata and scripts only.

## Save the sanitized output

Save with a full rewrite so removed objects don't remain in the file body:

```csharp

CheckStatus(pdf.SaveToFile(@"sanitized.pdf", true), "SaveToFile");
File.WriteAllText(@"sanitize-report.json", reportJson);

```

The second `SaveToFile` parameter enables a full rewrite of the file. This is important for sanitization because incremental saves preserve older revisions.

## Inspect the report

Print the JSON report path for downstream logging or review:

```csharp

Console.WriteLine("Sanitized PDF written to sanitized.pdf");
Console.WriteLine("Sanitization report written to sanitize-report.json");

```

The report contains per-category counts for removed objects and entries.

## Error handling and validation

Check the `GdPictureStatus` returned by `LoadFromFile`, `Sanitize`, and `SaveToFile`. In production, verify that the sanitized output doesn't expose sensitive data through text extraction, metadata inspection, attachments, annotations, or JavaScript actions.

## Conclusion

This workflow removes supported hidden and private data from a PDF, saves the cleaned document, and writes a JSON report for audit or troubleshooting.
---

## Related pages

- [PDF security in C#](/guides/dotnet/security.md)