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Home / Blog / Flatten PDF Online for Free without Losing Quality 2023

Flatten PDF Online for Free without Losing Quality 2023

By Lena | Follow twitter | Updated on August 29, 2023
PDF is an important format for document sharing. However, PDF files usually contain many interactive elements, so the content can be easily tampered with. To ensure the integrity of the content, we need to make it uneditable. This guide will show you how to flatten PDF online for free!

Why Need to Flatten PDF Online?

Flattening PDF allows a PDF file with layered or interactive elements to be converted to a non-editable image-based PDF file. In this way, you can rest assured that important forms won't be tampered with, the document will look the same on any device and print as expected. Flattening PDFs also reduces the size of PDFs, making them easier to store and transfer.

Perhaps you already know that you can use PDF tools to help you flatten PDF. However, since you don't work with PDF documents very often, or due to a lack of space on your computer, you'd prefer to learn how to flatten PDF online. Well, You can indeed flatten PD online for free, but before you begin, it is necessary to understand the advantages and disadvantages before taking action.

Pros and Cons of Flattening PDF Online

Compared with the use of desktop PDF tools, online PDF flattening is more convenient and fast, but its shortcomings can not be ignored.


  • No need to install software.
  • Save space on your computer.
  • Easily share the flattened PDF file via URL.


  • It requires the Internet to work. If the network is poor, it may take a long time to finish.
  • Uploading and downloading files online carries the risk of data leakage.
  • Not suitable for flattening large documents.

In short, when you want to flatten a small file, online tools can help you do it quickly. If you want to flatten a large file or a file that contains important or sensitive information, an offline PDF tool would be a better choice. You can choose according to your needs. Next, I’ll show you how to flatten PDF online and offline.

If you think you might need the offline tool but haven't made up your mind yet, then you can first click the button below to get the installation package for the tool. In this way, after you read below and realize that the online flatten tool is not for you, you can quickly install the tool and start flattening PDF files.

SwifDoo PDF
  • Batch flatten PDFs in seconds with no loss of quality
  • Convert PDF to Word, Excel, PowerPoint and other formats
  • Modify, add, delete or replace text/image with a single click
Free Download
Windows 11/10/8.1/7/XP

How to Flatten PDF Online

Let’s start to see how to flatten PDF online without quality for free. You can choose to use the PDF viewer of Chrome or an online PDF flattener.

Flatten PDF Online with Chrome

Most browsers like Chrome, Microsoft Edge, Firefox, etc. have a built-in PDF viewer that can help users open PDF online. In addition to viewing PDF files, there are many other useful features such as flattening the PDF. Below are the steps to flatten PDF online with Chrome.

1. Right-click the PDF file you want to flatten > Click Open with > Choose Google Chrome.

2. Click the Printer button and adjust the printing details.

3. When it’s OK, click the Print button > Choose a path to save the file.

Flatten PDF Online with Chrome

Flatten PDF Online with Online PDF Tool

If you prefer to use a web-based PDF tool to help you flatten PDF online, then Sajeda, PDF24 Tools, Smallpdf are all good choices. These online tools can also help you edit, compress, and merge files. Here we take Sajeda as an example to show you how to flatten PDF online for free.

1. Open your browser and go to https://www.sejda.com/flatten-pdf.

2. Click Upload PDF files to upload your file.

3. Select Flatten everything or Flatten only form fields as per your needs.

4. You can click More options to adjust the image resolution.

5. Click Flatten PDF to start the process.

Flatten PDF Online with Online PDF Tool

6. When it’s down, click Download to save the file.

How to Reduce PDF File Size without Losing Quality | 7 Ways

How to Reduce PDF File Size without Losing Quality | 7 Ways

This guide will tell you how to reduce PDF file size without losing quality. In this way, you will be able to manage, process or share PDF files more easily!


How to Flatten PDF Offline on PC and Mac

If you need to flatten a large PDF file, or one that contains important content, then you can let a professional PDF tool do you a favor. In the following, we will explain how to flatten PDF without losing quality on Windows and Mac computers respectively.

Flatten PDF on PC with SwifDoo PDF

On a Windows computer, you can use SwifDoo PDF to flatten PDF. It is one powerful yet lightweight PDF tool. You can choose the pages that need to be flattened, the whole process can be completed in a few seconds. In addition, it also allows you to batch flatten multiple PDF files. Let’s see how to use this tool.

1. Download, install and launch SwifDoo PDF.

2. Click the Convert option from the top bar > Then choose Flatten PDF.

3. Click Add Files to add the file you want to flatten.

4. Select an output path.

5. Click Start to flatten PDF without losing quality.

Flatten PDF on PC with SwifDoo PDF


  • If you just want to make PDF non-editable, you can also add a password to the file to restrict editing via the Encryption function.
  • When you want to make PDFs editable, you can take advantage of the OCR feature of SwifDoo PDF.

Flatten PDF on Mac with Preview

On a Mac computer, you can use the built-in Preview app to flatten PDF. The Preview app isn't just an image viewer, it's also a PDF editor. It can help flatten PDF files, add annotations, reduce PDF file size, etc. You can follow the steps below to flatten PDF without losing quality.

1. Open the PDF file you want to flatten with Preview.

2. Click File from the menu bar and choose Print.

Flatten PDF on Mac with Preview

3. Click the Save option and the file will be saved as a flattened PDF file.

Final Words

That’s all about how to flatten PDF online for free. Using an online PDF tool is a good idea if you want to achieve your goal quickly. While online tools advertise that your files are safe, there is always the possibility that the web can be hacked. On the other hand, if you're trying to flatten a large file, or need to flatten in bulk, a desktop program can save time and energy.

Lena has been in the editing industry for 8 years. She is familiar with a variety of products that can make things easier, such as PDF tools, video recording software, iOS location changer, etc. She enjoys sharing her knowledge with users to help them solve problems in their work and life. In her spare time, she likes to play with her cat.

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