The PDF Merger copies every input page into a new PDF in the displayed file order. Originals stay unchanged. A two-page report plus a one-page attachment produces three pages. Use the visible list rather than assuming filename or picker order.
Verify order with two small PDFs
| Displayed files | Output page order | Count |
|---|---|---|
| A.pdf with 2 pages, B.pdf with 1 | A1, A2, B1 | 3 |
| Reordered to B.pdf, A.pdf | B1, A1, A2 | 3 |
| Only A.pdf | Merge remains disabled | At least two files required |
Order inside each file is retained. The merger does not expose page-level reordering or selective merging. Extract a range with the PDF Splitter first, then merge those outputs.
Select, reorder, generate and save
- Select or drop at least two PDFs whose contents you have checked. Adding more appends them to the list.
- Use the up/down controls to reorder files and remove unwanted ones. Review the list from top to bottom.
- Select Merge and wait for the result card. Selection alone does not generate output.
- Select Download on the card; it is not an automatic download.
- Open the saved PDF in a viewer and check it before sharing.
The output name comes from the first file. If it is report.pdf, the output is report_merged.pdf. Reordering can change that first filename; avoid confusing a new output with an earlier download.
Pre-sharing checklist
| Item | Check |
|---|---|
| Count and order | Compare with the input total and inspect file boundaries |
| Text, figures and page sizes | Zoom in; mixed sizes are not normalized or reflowed |
| Annotations and forms | Check required comments, links and field values |
| Signatures | Distinguish a visible signature image from cryptographic validation; retain originals |
| Actual attachment | Select the checked output rather than the source file |
Copying pages creates a new document. There is no guarantee that document-level bookmarks, settings, form structures, attachments or signature-validation data transfer. Check the creator’s and recipient’s requirements for signed or submission-ready documents. This tool does not verify signatures.
Encryption, capacity and timing limits
The underlying pdf-lib does not support editing encrypted PDFs. This interface has no password-entry or removal feature. For documents you are authorized to edit, obtain an appropriate editable copy from the creator.
Merging is not compression. Image-heavy files can remain large; output bytes need not equal the sum of input sizes. There is no PDF compression, password-setting or redaction feature. Memory and document structure affect processing time; no universal file-count or seconds-to-completion guarantee is claimed.
PDF processing occurs in the browser without an input-file upload implementation. Opening the page or loading code can still involve network requests. Check download locations on shared computers.
Frequently asked questions
Will merging meet a submission size limit?
Not necessarily. Compare the saved output’s size with the actual limit.
Can I merge only selected pages?
This screen copies all pages. Extract the required ranges first.
Is the file saved when the result card appears?
No. Use Download and then open the saved file to verify it.
Return to the same workflow
Open the PDF Merger, reproduce the small example and inspect the result before processing your own data. Favorite the tool near its name to reopen it through My Tools in the same browser. Favorites store the tool choice, not your inputs or files; clearing site data removes them. Keep any desired file-order notes separately for the next session.
Scope and evidence
On October 25, 2026 we compared these steps and examples with the published implementation. Primary references support the standard or API; the output tables and limits describe Tools Hub. This is not a speed or capacity benchmark, a guarantee for every environment or professional certification.
