Introduction

Are you looking for a tool to combine multiple PDFs into one? Many free tools out there are either slow, cluttered, or filled with ads. Finding one that’s fast, user-friendly, and truly free isn’t easy. You shouldn’t have to register just to merge a few files. In this blog, we explore the top five free, online PDF merging tools that are simple, effective, and don’t require any sign-up. 

Things to Consider Before Selecting a PDF Merging Tool 

To choose a free tool to merge PDFs, a user should consider the following criteria: 

  • No Forced Sign-Up: The best tools let you get started instantly—no accounts, no email traps, just merge and go. 
  • Secure File Handling: Your documents should be processed securely, never stored on a server or deleted automatically after use. 
  • Easy to Use: Look for an intuitive interface with drag-and-drop functionality, clear steps, and zero learning curve. 
  • Generous Limits: A useful tool won’t cap your uploads with tiny file size or page count restrictions. 
  • Advanced Page Control: Being able to re-arrange, rotate, delete, or preview pages before merging adds real flexibility.  
  • No Watermarks: A truly free tool won’t slap a watermark on your final document. 

A Side-by-Side Comparison: Top 5 Free PDF Merge Tools 

The following table compares different free tools’ features and usability.  

Feature Smallpdf PDF24 PDF.io PDF Converter
Use tool without sign-up? Yes Yes Yes
Pricing Free Free (up to 25 files/day). Premium plan allows unlimited usage Free (basic features). Subscription required for advanced features and unlimited usage
Minimum files required to merge 2 1 2
Supported file formats PDF, Word, Image, PPT, Excel PDF PDF, Word, PPT, Excel, Image, iWork, Open Office
File upload locations Local, Dropbox, Google Drive Local, Google Drive, Dropbox, URL Local, Google Drive, Dropbox, URL
PDF save location Local, Email, Dropbox, Google Drive, Fax Local, Google Drive, Dropbox Local, Google Drive, Dropbox
Add files between pages No No No
Yes Yes No (Sign up required for unlimited)
No limit Yes (25 files/day, unlimited with Premium) Yes (2 tasks/hour, unlimited with Subscription)
Yes Yes Yes
Yes No No
No Yes Yes
No No No
Yes (files only) Yes (files only) Yes
Yes No No
Yes Yes Yes
List and grid Grid only Grid only
Server-side. Deleted after 1 hr. Server-side. Deleted after 12 hrs. Server-side. Deleted after 3 hrs.
500 MB 4 GB (up to 10GB with Premium) Unlimited file size with premium
Yes Yes Yes
No No Yes
No Yes No
Yes No No
No No No
Yes Yes Yes
Yes Yes Yes
No No No
Simple Basic interface Easy to use
Large-file merging Multi-source merging Simple, versatile merging

Security and Privacy Considerations 

Why Security Matters

When merging PDFs online, security is crucial—especially for sensitive documents like contracts or financial records. Many free tools process files on remote servers, which can increase the risk of data breaches or unauthorized access. Users should ensure that the tool they choose either processes files entirely on the client side (with no uploads), or, if server-based, has strict deletion policies with short retention times.  

Best Practices for Security and Privacy

  • Choose Client-Side Processing: Prefer tools that handle files locally, so nothing is uploaded to a server.
  • Check Deletion Policies: Ensure server-based tools delete uploaded files immediately or within a short timeframe. 
  • Use Secure Connections: Always merge PDFs over HTTPS to protect your data during transmission.  
  • Avoid Uploading Sensitive Data: Redact private information before using server-side tools.  
  • Verify the Tool’s Reputation: Check the provider’s privacy policy and user reviews to confirm it’s trustworthy.

How BoldSign Ensures Security 

BoldSign’s free PDF merger uses client-side processing only—your files never leave your device. This eliminates the risk of data exposure on external servers and ensures total control over your documents. Combined with a strong privacy policy, this makes BoldSign one of the safest options available. 

The BoldSign PDF merger:

  • Is a 100% free tool.
  • Requires no sign-up or commitment to use.
  • Adds no watermarks to your final PDF.
  • Works on any device with unlimited usage.

Conclusion 

Free, online PDF merging tools make document management fast and easy. BoldSign stands out as a top choice thanks to its secure, user-friendly design, client-side processing, and powerful merging features like page reordering—all with no sign-up required. Whether you’re a student, professional, or small business, BoldSign helps you merge PDFs effortlessly while keeping your data safe.