If you sell or distribute PDF documents then PDF.co can help with protecting your documents from unauthorized access, modification, or data extraction. It can be as simple as adding a watermark to your document. So if someone just copies your file, your watermark will stay. There’s a more advanced feature such as PDF file built-in encryption.

There are five (5) levels of protection that you can implement with PDF.co Web API.

  1. PII or Sensitive Data Removal/Redaction – to redact sensitive data (video guide)
  2. Document Watermarking – adding the customer’s name, date, order id, or your company name to output PDF
  3. PDF built-in Security – leverage built-in PDF encryption
  4. Make PDF Unsearchable – make it harder to copy text from the document
  5. Convert PDF to Image – turning PDF into an image can make it readable with human eyes but harder to extract text

PII or Sensitive Data Removal/Redaction

The first level of protection is removing sensitive information such as Name, Social Security Number, Credit Card Number, etc., in a PDF document. This can be accomplished using the Replace Text function or the /pdf/edit/replace-text endpoint. The replacement or text removal is very straightforward. You only need to specify the text that you want to remove, and the engine will do the rest.

In our demonstration below, we will remove the company name in the document.

Remove Sensitive Data Demo
Remove Sensitive Data Demo

Document Watermarking

The second level of protection is adding a watermark to your document. Watermarking not only highlights your ownership but also the image overlay makes it hard to extract the contents of the document. With PDF.co, you can use the /pdf/edit/add endpoint to add either a text watermark or an image watermark.

In the demonstration below, we will add a company logo at the center of the document.

Document Watermarking
Document Watermarking Demo

PDF built-in Security

The third level of protection is leveraging the built-in PDF security options. These options include file content encryption, user and owner passwords, content extraction restriction, and more. With PDF.co’s /pdf/security/add function, you can have access to tons of security features that gives you control over your document.

To see it in action, we will demonstrate how to add a user and an owner password in a document.

PDF Built-In Security
PDF Built-In Security Demo

Make PDF Unsearchable

The fourth level of protection is making your PDF unsearchable. This function replicates the process of printing the PDF document and scanning it back without the text recognition. This can easily be done using the /pdf/makeunsearchable endpoint.

We will convert a searchable PDF into an unsearchable PDF in the demo below.

Make PDF Unsearchable Demo
Make PDF Unsearchable Demo

Convert PDF to Image

Aside from turning your PDF into an unsearchable PDF, you can also convert the document into a set of images. The /pdf/convert/to/jpg endpoint will convert your PDF document into JPG. Other supported formats are PNG and TIFF.

In the demonstration below, we will convert a 2-page PDF into two (2) separate JPGs.

PDF to JPG Demo
PDF to JPG Demo

The key here is to review JPG images output quality. Try different levels of quality for the output image. For example, try to set this pretty low resolution that will make it hard to recognize text using computer applications but still can be readable with human eyes. You can control the quality via the profiles parameter. For example, set the low quality of 50 dpi (50 dots per inch):


"profiles": "{ 'RenderingResolution': 50 }"

Need to try on your specific documents but here is the example to compare different rendering resolutions:

240 dpi resolution:
pdf to jpeg with 240 dpi

50 dpi resolution:
pdf to jpeg with 50 dpi

30 dpi resolution: (well it is really unreadable now)
pdf to jpeg with 30 dpi

You are welcome to try all these functions at the PDF.co Request Tester. The Request Tester is a no-code online tool with ready-to-use samples. You can access it here https://app.pdf.co/request-tester

PDF Protection Video Tutorials