Best Free Tools to Merge PDF Files Online in 2025

Merging PDFs is a common task for professionals, students, and freelancers who deal with multiple documents. Whether it’s combining reports, contracts, or presentations, having the right tool to merge PDF documents can save time and improve workflow efficiency. 

What to Look For in a Free PDF Merge Tool

When selecting a free PDF merge tool, it’s important to keep a few factors in mind to ensure you’re getting the best experience:

Security and Privacy Protection

Since you’ll be uploading documents online, it’s crucial to use a tool that offers SSL encryption and complies with privacy regulations. Look for platforms that promise to keep your documents secure and confidential.

File Size Limits and Speed

Free tools often have restrictions on file sizes. Ensure that the tool you choose can handle large PDF files without slowing down your workflow. Look for tools with fast processing speeds to save time.

Output Quality and Formatting Retention

When merging PDFs, it’s important that the formatting is preserved. The last thing you want is a jumbled or misaligned output. Choose a tool that ensures high-quality results with minimal formatting issues.

Cloud Integration (Google Drive, Dropbox, etc.)

If you work in the cloud, opt for a tool that integrates with services like Google Drive or Dropbox. This way, you can easily access and merge your documents from anywhere.

User Interface and Mobile-Friendliness

An intuitive, easy-to-use interface is key to saving time. A mobile-friendly platform is also a great bonus for those who need to merge PDFs on the go.

Top Free PDF Merge Tools in 2025

Here’s a look at the best free PDF merge tools for 2025:

1. Lumin

Lumin stands out as one of the best tools for merging PDF files online. It’s known for its clean interface, cloud integration, and seamless collaboration features, making it a top choice for professionals and teams.

Features and Ease of Use

• Simple drag-and-drop functionality for merging PDFs.

• Cloud-based platform for easy access from anywhere.

• Real-time collaboration for teams working on the same document.

File Limits for Free Users

• Free users can merge PDFs with basic features, but are limited in terms of file size and the number of documents they can process.

Pros and Cons

Pros:

• Seamless cloud integration (Google Drive, Dropbox).

• Easy-to-use interface with minimal setup required.

• Secure, encrypted file handling.

Cons:

• Some advanced features are limited to paid plans.

2. Smallpdf

Smallpdf is another popular option for merging PDF files. With its user-friendly interface and wide range of features, it’s a solid choice for occasional PDF merging tasks.

Drag-and-Drop Functionality

• Easy to use with a simple drag-and-drop interface for merging PDFs.

Security Compliance (GDPR, SSL Encryption)

• Smallpdf complies with GDPR and offers SSL encryption to keep your documents safe.

Integration with Google Drive

• Smallpdf integrates with Google Drive, allowing users to merge PDFs directly from their cloud storage.

Pros and Cons

Pros:

• Simple, no-fuss interface.

• Secure encryption and cloud integration.

• Free version includes essential features.

Cons:

• Limited functionality in the free version, with a daily task limit.

3. iLovePDF

iLovePDF is a comprehensive PDF editing tool with a focus on merging, splitting, and converting PDFs. It’s perfect for users who need to process multiple files quickly.

Bulk Merging

• iLovePDF supports bulk merging, which is ideal for users who need to combine multiple PDFs at once.

Cloud Storage Access

• iLovePDF allows easy integration with cloud services like Google Drive and Dropbox for quick access to your documents.

Mobile and Desktop Versions

• iLovePDF offers both mobile and desktop versions, making it convenient for users who need to work across devices.

Pros and Cons

Pros:

• User-friendly design.

• Cloud integration for easy document management.

• Efficient bulk merging for large tasks.

Cons:

• The free version has a daily limit for merging PDFs.

4. PDF Candy

PDF Candy offers a variety of free tools for managing PDFs, including merging PDFs into one. It’s great for users who need a lightweight tool with additional editing features.

Pros and Cons

Pros:

• No sign-up required.

• A variety of additional PDF tools are available for free.

• Offline mode for desktop users.

Cons:

• The free version has a limited number of tools and can be slow for large files.

5. PDF24 Tools

PDF24 Tools is a free PDF editor that offers an easy-to-use PDF merging tool along with additional features such as PDF compression and conversion.

Free Desktop and Web App

• PDF24 Tools provides both a desktop and web app, allowing for flexibility in how you access the tool.

Unlimited Usage

• Unlike many other free tools, PDF24 doesn’t impose strict limits on the number of PDFs you can merge.

Privacy Benefits

• The tool doesn’t require users to upload files to the cloud, keeping your documents local and secure.

Pros and Cons

Pros:

• No upload required, keeping documents private.

• Unlimited use with the desktop app.

• Comprehensive PDF tools available.

Cons:

• The web version is slower for large files.

• Desktop app is only available for Windows.

6. Sejda PDF

Sejda PDF is an online PDF editor that provides a variety of tools, including the ability to merge PDFs. It’s an ideal option for users who need to handle both small and large PDF tasks.

Merge, Compress, and Convert

• Sejda allows users to merge, compress, and convert PDFs, making it a versatile solution.

Limitations on Free Plan

• The free plan allows for three tasks per hour, which can be limiting for frequent users.

Interface and Accessibility

• Sejda has a clean, user-friendly interface that’s easy to navigate for both beginners and professionals.

Pros and Cons

Pros:

• Great for quick, simple PDF merges.

• Includes extra features for compressing and converting files.

Cons:

• Limited free plan with file size restrictions.

Security and Privacy Tips When Merging PDFs

When merging PDF files online, it’s important to keep security and privacy in mind. Here are a few tips to ensure your documents are protected:

Use Tools with SSL Encryption

Always choose PDF merging tools that use SSL encryption to secure your file transfers and protect your sensitive data.

Avoid Uploading Confidential Documents

If possible, avoid uploading highly sensitive documents to online PDF merge tools. For more secure handling, use offline tools or ensure the tool’s privacy policy covers data protection.

Delete Files After Download

Many online tools give you the option to delete your files after downloading them. Always make sure to remove files from the server to prevent unauthorized access.

Final Thoughts

When it comes to merging PDF documents, choosing the right tool depends on your specific needs. Lumin offers a powerful, secure, and user-friendly solution for freelancers and small businesses looking for efficient document management. However, tools like Smallpdf, iLovePDF, and PDF24 Tools provide solid free alternatives for users needing basic features.

Regardless of the tool you choose, always prioritize security, file size limitations, and the ease of use when selecting a PDF merge tool. With the right solution, you can improve your document workflow, save time, and boost productivity.