Handling large files in Python can indeed present challenges, particularly when it involves merging multiple PDFs into a single PDF document. As PDF files can contain complex structures and graphics, processing large PDFs can be resource-intensive and time-consuming. This is especially true when dealing with a significant number of PDF files to merge, as each file needs to be read, processed, and combined into the final output.
The PDF.co Web API’s smooth integration with Python makes it an ideal choice for developers seeking an efficient solution to merge large PDFs. By utilizing Python’s capabilities and leveraging the PDF.co API, developers can simplify the merging process, reducing complexities and enhancing overall performance.
In this comprehensive guide, we will walk you through the steps to merge large files in Python using PDF.co Web API. PDF.co is a cloud-based API that harnesses cutting-edge technology to handle PDF-related tasks, including merging, splitting, text extraction, and more.
- Install the Request Module
- Open Visual Studio Code Editor
- Setup Python Code
- Run the Program Result
- Merge PDF Output
- PDF.co PDF Merge Demo

Follow this simple step-by-step guide to merge large PDF files into a single PDF.
Step 1: Install the Request Module
- To begin, let’s start by installing the request module to manage new packages written in Python. In your command line, type
python -m pip install request
and click the Enter button to install the request module.
Step 2: Open Visual Studio Code Editor
- After installing the request module, open the Visual Studio Code Editor. You can also use your favorite editor in Python.
- Next, add the Python sample code. You can get the Python sample code at this link.
Step 3: Setup Python Code
Now, let’s set up the Python code.
- Add your PDF.co API Key in line 6. You can get the API Key in your PDF.co dashboard. If you don’t have an account, kindly sign up to PDF.co to get an API Key.
- In lines 12 and 13, input the source PDF file names. You can download the sample PDF files at this link.
- For line 16, enter your desired output file name of the merged PDF files.
After setting up the Python code, save the file and click the Run button to execute the program.
Step 4: Run the Program Result
- Once the program runs successfully, check your Python program folder to view the output.
Step 5: Merge PDF Output
- Here are the large PDF files that we successfully merge into a single PDF.
Step 6: PDF.co PDF Merge Demo
- Check out this PDF.co PDF Merge in action.

In this tutorial, you learned how to merge large PDF files using Python. You also learned how to use the PDF.co Web API to merge large PDF files into a single PDF.