How to Fix Adobe Acrobat Taking Too Long to Combine PDFs
Question details
The user is experiencing significant delays when trying to merge two small PDF documents.
- Product
- Adobe Acrobat
- Device & OS
- not provided
- Scenario
- Attempting to merge two six-page PDF files quickly for an urgent task.
- Observed behavior
- The file combination process takes an unusually long time to complete or gets completely stuck.
Ensure both of your PDF files are saved locally on your device rather than on a network drive or cloud storage, as slow synchronization can drastically delay the merging process.
Troubleshoot Acrobat and Optimize Files
Resolve common performance issues by checking file accessibility, closing background tasks, and restarting the software.
Even small PDF files can cause Acrobat to hang if they contain complex hidden layers or if system resources are depleted.
Open both six-page PDF files individually in Acrobat to ensure neither file is corrupted, damaged, or password-protected.
Close your web browser and other heavy applications running in the background to free up RAM and CPU resources for Acrobat.
Go to Help > Check for Updates in Adobe Acrobat to ensure you are running the latest version, which may contain bug fixes for performance issues.
Completely close Adobe Acrobat, reopen the program, and attempt to use the Combine Files tool with the locally saved copies again.
Flatten the PDFs Before Merging
Use the Print to PDF feature to flatten complex data, which often eliminates errors that cause merging delays.
Merge PDFs Instantly with WPS Office
If Acrobat continues to freeze or process too slowly for your urgent task, use WPS Office to quickly combine multiple PDF files in seconds. WPS Office features a lightweight, high-performance PDF engine that eliminates freezing and handles file merging seamlessly.
- 1. Launch WPS Office: Open the WPS Office desktop app and click on the 'PDF' tab from the main dashboard.
- 2. Access the Merge Tool: Navigate to the 'Tools' tab in the top ribbon and select 'Merge PDF'.
- 3. Add your documents: Click 'Add Files' and select the two six-page PDF files you need to combine from your local folder.
- 4. Complete the merge: Review the file order, choose your desired output location, and click 'Merge' to instantly create your combined document.
Frequently Asked Questions
Why does my PDF take so long to merge?
PDFs can take a unexpectedly long time to merge if they contain high-resolution uncompressed images, complex vector graphics, interactive forms, or embedded fonts. Furthermore, merging files stored on a slow network drive or cloud service can cause severe delays.
Can a slow internet connection affect PDF merging?
Yes. If you are using cloud-based PDF merging tools or if your files are syncing from a cloud drive (like OneDrive or Dropbox), a slow internet connection will bottleneck the loading process, making the merge take significantly longer.
How can I reduce the size of a PDF before combining it?
You can reduce the file size by opening the PDF and using the 'Compress PDF' or 'Reduce File Size' feature available in your PDF editor. Downsizing heavy images and stripping unnecessary metadata makes the merging process much faster.
Is there a limit to how many pages I can merge in a PDF?
Most professional desktop software like Adobe Acrobat or WPS Office do not have strict page limits, though overall performance will depend on your computer's RAM. Conversely, free online merging tools often cap operations at 50-100 pages or a specific file size limit.
