How to Compare PDF Online Using PDF AI Tools


In today's digital world, managing and comparing documents efficiently is crucial, especially when dealing with important files like PDFs. Whether you're collaborating on a project, reviewing changes in contracts, or simply ensuring accuracy between document versions, having the right tools to compare PDFs can save time and reduce errors. This blog will guide you through the process of comparing PDF files online using various tools, including ChatDOC and Adobe Acrobat. By following our step-by-step instructions, you'll be able to quickly and accurately identify differences between your documents, making your workflow smoother and more efficient.

Common steps you need to follow

To compare PDF files online, you can use various tools and services designed for this purpose. Here's a general guide on how to do it:

Choose an online tool

There are several online tools available for comparing PDF files. Some popular ones include ChatDOC, Adobe Acrobat and PDF AI. Choose one that fits your needs and preferences.

Upload PDF files

Once you've selected a tool, go to its website and look for the option to upload or select the PDF files you want to compare. Usually, you'll find a button like "Upload" or "Choose File."

Initiate comparison

After uploading the PDF files, initiate the comparison process by clicking on the appropriate button or option. The tool will analyze the contents of both files and highlight any differences between them.

Review comparison results

Once the comparison is complete, the tool will display the results, typically highlighting changes, additions, deletions, or other modifications between the two PDF files. You can review these differences to understand what has changed between the versions.

Download or save

Depending on the tool, you may have the option to download the compared PDF file or save the results for future reference. Make sure to save the results if needed.

Optional: share or collaborate

Some tools also offer features for sharing or collaborating on compared PDF files. If you're working with others, you can use these features to streamline the review process.

How to compare pdf files online using ChatDOC

ChatDOC ( offers a user-friendly solution that simplifies the process. Follow these steps to effortlessly compare your PDFs:

Upload the PDFs you need to compare online

Create a new collection to upload PDFs, or simply drag and drop the existing folder. You can chat with any number of PDFs at once.


Ask AI about the differences between PDFs

Input the instruction and let the AI compare the PDFs for you in seconds.


Trace back to the original paragraph to view details

Click the number after the sentence you want to explore further, and you can easily skip to the original section.


Download the results

You can choose to download the dialogue in formats including Markdown, HTML, or PNG. You can also decide whether to export all the answers or just the ones you liked.


Share the chat with others

Share the dialogue within groups to help others quickly understand the documents.


How to compare PDFs in Adobe Acrobat

Comparing PDFs in Adobe Acrobat ( is a straightforward process, especially with the advanced features available in Adobe Acrobat Pro DC. Here’s how you can do it:

Open Adobe Acrobat Pro DC

Make sure you have Adobe Acrobat Pro DC installed. This feature is not available in Adobe Acrobat Reader.

Select the compare files tool

  • Go to the "Tools" tab at the top left of the screen.
  • Scroll down and select "Compare Files" from the list of tools.

Add the files for comparison

  • In the Compare Files tool, you will see two options: "Select File" on the left side for the older file (File A) and the other on the right side for the newer file (File B).
  • Click on "Select File" on both sides to upload the PDFs you want to compare.

Start the comparison

  • Once the files are uploaded and settings adjusted (if necessary), click on the "Compare" button.

Review the comparison results

  • Adobe Acrobat Pro DC will process the files and open a new window with the comparison results.
  • The differences will be highlighted, and you can navigate through the changes using the provided tools (e.g., previous change, next change).

Detailed report

  • You can also generate a detailed report of the comparison by clicking on the "Summary" button. This report can be saved as a PDF.
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