Flatten Annotations API Tool - Collapse PDF Annotations to Page Content

Flatten Annotations is a REST API tool that collapses annotation appearances into page content and makes them no longer editable. It's designed to provide developers with precise control over document finalization, ensuring PDF annotations display consistently across all viewers and platforms while safeguarding against unintended modifications.

Key Benefits of Flatten Annotations API

Maximize compatibility by converting diverse PDF annotation types into standard page content, ensuring universal display across all PDF viewers and processing tools.
Lock in feedback by preserving highlights, comments, and shapes directly into the document's content layer, preventing further editing or accidental changes to critical review notes.
Remove hidden comments and associated metadata from annotations, effectively sanitizing the PDF to ensure only visible content remains, enhancing document security and privacy.
Streamline document workflows by creating definitive versions of PDFs with finalized annotations, ideal for archiving, distribution, or legal purposes.
Enhance document integrity by making all annotation appearances permanent, crucial for audit trails and compliance requirements.
Automate the preparation of PDFs for consistent viewing and printing, eliminating rendering inconsistencies often associated with dynamic annotations.

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Request

POST

Headers

Api-Key

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Response-Type

Choose between a full response after processing completes or an immediate response containing only the requestId to poll for the processing status later.

Full Response

Request ID

Required Parameters

file

File to be uploaded and processed

Alphanumeric ID (UUID) of existing file on server to be processed

Optional Parameters

output

Name of the generated output file, without extension

Code

curl -X POST "https://api.pdfrest.com/flattened-annotations-pdf" \
  -H "Accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -H "Api-Key: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" \

Response

The response for your API Call will display here.

Once you've sent your POST request and received a valid response, you can download your output file using the output URL.

Build Your Solution

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Why is pdfRest the best API to flatten PDF annotations?

pdfRest offers the best solution for flattening PDF annotations, because it maximizes compatibility, locks in feedback, and removes hidden comments.

Maximize Compatibility

Not all PDF viewers and processing tools handle PDF annotations in the same way. PDF annotations come in a variety of types, can be added in varying ways, and can be rendered with inconsistent results. In the worst cases, some tools or services may fail to display annoations at all.

pdfRest Flatten Annotations removes uncertainty by turning annotation objects into standard page content, ensuring they will display the same for all users. When preserving annotation appearances is key, trust the pdfRest flattening process to maximize support and compatibility.

Lock In Feedback

PDF annotations are often used to provide feedback for the underlying PDF on top of that document's content layer. This feedback travels with the document and can be further edited or modified at any point. Shapes can be moved, highlights can be adjusted, annotation text can be changed.

When you no longer want this feedback to be editable, flattening annotations is the best way to lock that feedback directly into the document and preserve it as standard page content. This supports a workflow for review, feedback collection, and feedback communication, avoiding confusion or inadvertent changes to the feedback.

Remove Hidden Comments

PDF annotations can include both visual elements that are displayed in the document and hidden comments that are associated with these annotations. These extra comments can only be accessed with supported PDF viewers and displayed off to the side of the document. Flattening annotations preserves the visual representation of annotations directly into the content layer of the PDF and also removes these hidden comments, which may include information not intended to travel with the document. Flattening annotations is an effective way to sanitize annotation content so that what you see on the PDF is all that remains from the original annotations.

Start from Code Examples

See more code examples in our GitHub repository

Need more help?

Start with a Tutorial for step-by-step guidance

How to Flatten Annotations in PDF Files in .NET with C#

How to Flatten Annotations in PDF Files with JavaScript in NodeJS

How to Flatten Annotations in PDF Files with PHP

How to Flatten Annotations in PDF Files with Python

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Customize Your Solution

Learn about the parameters for this tool to create your custom solution.

File

The file parameter allows you to select a local file to be uploaded to pdfRest’s processing server.

See Documentation

The id parameter allows you to submit a resource ID generated by one of our API Tools. Each of our API Tools assigns a unique resource ID to your output file(s), allowing you to chain requests together without having to download intermediate files between requests.

For example, you can submit the output ID you receive from our Merge PDFs tool to flatten your new PDF before you download it.

See Documentation

Output

The output parameter lets you set a filename (without extension) for your flattened PDF.

See Documentation