Merge PDFs
Combine two or more PDF files into one document in the order you arrange them.
Drag and drop multiple PDF files here or click to browse
Supported: .pdf (select at least two)Merging Tips
Order before merge
Drag files into the final reading order. The merge follows the list order sent with the request.
Unlock protected files first
There is no password field. Encrypted PDFs must be unlocked before upload.
Upload size
Server upload limits are about 100 MB for the request. Very large batches may fail or take longer.
Multi-file merge
Requires at least two PDF files. Combine more in one run when the request size allows.
Drag-and-drop order
Reorder selected files in the UI before starting the merge.
Single PDF download
Output is one PDF (merged-document.pdf), not a ZIP of separate files.
What this tool does
Merge PDFs combines two or more PDF files into a single document in the order you set in the file list.
Use it when sections live in separate files (cover, chapters, appendices) and you need one attachment for sharing or upload portals.
How to use
Upload at least two PDFs
Select or drag multiple .pdf files into the tool.
Arrange the order
Drag files so the top-to-bottom list matches the final page order.
Merge and download
Start the merge and download the combined PDF when processing finishes.
Supported inputs and output
Input: two or more .pdf files. Output: one application/pdf file.
Mixed page sizes and orientations are kept as in the source files; the tool does not renumber pages for you.
Processing and privacy
Files are uploaded over an encrypted HTTPS connection and processed temporarily via Stirling-PDF on Toolomix’s conversion path.
Toolomix does not publish a verified universal file-retention clock for every conversion. See the Privacy Policy for how uploads and logs are handled.
Limitations
Known limits
- No password / encrypted-PDF unlock field
- No OCR for scanned pages
- No automatic page numbering
- Very large multi-file requests may hit the ~100 MB upload limit
- Corrupted PDFs may cause the merge to fail
Troubleshooting
If merge fails, confirm every file opens locally as a PDF, remove encryption, reduce total upload size, and try fewer files.
Server messages such as “At least 2 PDF files are required” or “Only .pdf files are supported” mean the request did not meet those rules.
PDF Merge FAQ
How many PDFs can I merge?
At least two are required. There is no fixed maximum count in the UI; practical limits come from request size (about 100 MB) and processing time.
Can I reorder files?
Yes. Drag selected files in the list. Order is taken from that selection sequence.
Are password-protected PDFs supported?
No password unlock is provided. Unlock files first, then merge.
Does merging recompress or OCR pages?
No. The tool concatenates PDFs via Stirling-PDF. It does not add OCR or change page content by design.
Where is my file processed?
PDFs are uploaded over HTTPS and processed temporarily on Toolomix servers through Stirling-PDF, then returned as a download.
What happens if one file is not a PDF?
Only .pdf files are accepted. Non-PDF selections are rejected by the client or server.
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Merge PDFs now
Upload at least two PDFs, arrange the order, and download one combined file.
