Merge PDF online — PDFWhirl

What Merge PDF does

Merge PDF appends the pages from each selected document to a new PDF. The file order shown in the workspace determines the order of the page groups in the result.

The operation combines whole documents. It does not rewrite page text, choose individual pages, or reduce the output file size.

How to use this tool

Select PDF files
Choose at least two PDFs from your device. The current interface accepts up to 30 files for one merge job.
Arrange the documents
Review the file tiles and drag them into the sequence you want in the combined document.
Start the merge
Select Merge PDF and wait while the job processes each document in order.
Download the result
When processing completes, download the single merged PDF and check its page sequence.

Common use cases

Assemble a submission

Place a cover sheet, supporting document, and appendix into one file before sending them together.

Join scanned sections

Combine separately scanned portions of a longer record without rebuilding every page.

Collect monthly documents

Put statements or reports into chronological order for easier storage and review.

Supported inputs

PDF documents (.pdf, application/pdf)
Two to 30 files through the current interface

Output

One PDF named merged.pdf, containing every input page grouped in the selected file order.

Limitations to know

Password-protected, malformed, or incomplete PDFs may not open in the PDF worker.
The tool joins whole files; use Extract Pages first when only selected pages are needed.
The combined file can be larger than each input because no compression step is applied.
Upload size is controlled by the active deployment and is not presented as a fixed public allowance.

Privacy and document handling

Selected PDFs are uploaded and stored so the merge worker can retrieve and process them.
The result is made available through a time-limited signed download URL.
No automatic stored-file deletion period is claimed; use the published privacy request channel for deletion questions because the public interface does not consistently expose the file API control.

Stored input and output objects are deleted automatically: files uploaded without an account are removed about 24 hours after upload, and files belonging to a signed-in account are removed after 7 days. A scheduled sweep enforces this hourly against the object store itself. Workers attempt to remove per-job temporary directories after processing. This does not delete stored input or output objects.

Read the Privacy Policy and Security page for verified implementation details and open questions.

Troubleshooting

The Merge button remains unavailable

Confirm that at least two files finished uploading and that every selected item is a PDF.

The documents appear in the wrong order

Return to the workspace, reorder the file tiles, and create a new merge job.

Processing fails on one file

Open each source PDF locally. Re-export a file that is damaged, incomplete, or requires a password, then try again.

Still stuck? Review Help and common questions or contact support.

Frequently asked questions

Does merging change the order inside each PDF?

No. Pages within each source remain in their existing order; only the order of the source documents is changed.

Can I merge only a few pages from a PDF?

Not directly in this tool. Use Extract Pages to create a smaller PDF, then include that result in a merge.

Will bookmarks and interactive features always remain identical?

The merge is page-focused. Review the output if your sources depend on document-level bookmarks, forms, signatures, or other interactive behavior.

How should I check my Merge PDF result?

Open every Merge PDF download and compare it with the unchanged source before sharing or deleting anything. Pay particular attention to this documented limitation: Password-protected, malformed, or incomplete PDFs may not open in the PDF worker.