Flatten Annotations

Flatten Annotations

Flatten Annotations is a REST API tool that collapses annotation appearances into page content and makes them no longer editable.

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Required Parameters
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" \
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.
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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
  1. First, you'll need an API Key - to:
    • Stay anonymous with a Guest API Key for 10 free API Calls
    • Sign up for an upgraded API Key with unlimited, continuous service
  2. Choose your programming language
  3. Copy and paste the code to your project
  4. Update Api-Key field with your unique API Key
  5. Update file with the local path to your input
  6. Run this code to send an API Call
See more code examples in our
GitHub repository
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curl -X POST "https://api.pdfrest.com/flattened-annotations-pdf" \
  -H "Accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -H "Api-Key: xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" \
  -F "file=@../Sample_Input/ducky.pdf" \
  -F "output=example_out"
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The file parameter allows you to select a local file to be uploaded to pdfRest’s processing server.

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