Flatten PDF annotations with Nutrient Document Web Services API on Zapier

Hulya Masharipov

February 3, 2025

In this tutorial, you’ll learn how to flatten annotations in PDF documents using the Nutrient Document Web Services API on Zapier. Flattening annotations is useful when you want to make highlights, comments, or form data permanent and prevent unauthorized changes.

Flatten PDF annotations with Nutrient Document Web Services API on Zapier

What is Zapier?

Zapier(opens in a new tab) is an automation platform that connects your favorite apps and services with no code required. You can build “Zaps” to automate repetitive tasks by setting up triggers and actions between apps like Google Drive, Slack, Gmail, and more.

In this tutorial, you’ll learn how to use Zapier to automatically flatten preexisting PDF annotations using the Nutrient API.

What is the Nutrient API?

Nutrient Document Web Services API is a powerful document automation toolkit. It supports more than 30 document operations like file conversion, redaction, OCR, digital signing, and flattening. With your free account(opens in a new tab), you’ll receive 100 credits to explore these features.

Why flatten annotations?

Flattening turns interactive annotations (like comments, highlights, form fields) into static elements in the PDF. This prevents others from editing or removing them — perfect for securing completed forms or reviewed documents.

What you’ll need

A Zapier(opens in a new tab) account (a pro plan is necessary for multi-step Zaps)
A Google Drive account
A PDF file uploaded to a Google Drive folder
A Nutrient API key — sign up here(opens in a new tab)

Step 1 — Trigger a new file in a Google Drive folder

Select Google Drive as the trigger app.

Select Google Drive as the trigger app in Zapier

Choose the New File in Folder trigger event.

Choose 'New File in Folder' as the trigger event

Connect your Google Drive account.
Set the folder you’d like to monitor for incoming PDFs.

Choose or create the input folder in Google Drive

Test this step to confirm Zapier detects the file.

Zapier test step confirming file detection from Drive

Step 2 — Flatten PDF annotations action

Select Nutrient Document Web Services API as the action app.

Select Nutrient API as the Zapier action app

Choose the Flatten PDF Annotations action.

Select 'Flatten PDF Annotations' action event

Paste your Nutrient API key to connect.

Enter API key to connect Nutrient account

You can get your API key from the Nutrient dashboard(opens in a new tab).

Where to find your Nutrient API key

Fill in the action fields:
- PDF File URL — Use the file URL from step 1
- Output File Name — Optional, e.g. final-report [Flattened].pdf

Map the PDF input and define the output file name

Test the action to confirm the PDF is successfully flattened.

Test results showing a successful flattening response

Step 3 — Upload the flattened PDF to Google Drive

Add Google Drive again and select Upload File.

Add Google Drive upload file action

Choose the drive and destination folder.
In the File field, use the output from the previous Nutrient step.

Map the flattened PDF output to upload it to Google Drive

Avoid Zap loops by selecting a different folder for uploads than your trigger folder.

Test to confirm the file uploads to your drive.

Zapier final test confirming the PDF was uploaded

Conclusion

You’ve just created an automated Zap to flatten PDF annotations using Nutrient API(opens in a new tab). This is ideal for securing completed forms or locking down reviewed documents. You can expand this Zap with steps for OCR, digital signing, or emailing the output.