June 12, 2026
How to Merge PDF Files Online
Combining multiple PDFs into one is straightforward — but page order, file limits, and password protection can trip you up. Here's everything you need to know.
When You'd Need to Merge PDFs
Combining a cover letter with a resume. Attaching appendices to a report. Consolidating monthly invoices into a single document for accounting. Assembling chapters written separately into one book file. Merging PDFs is one of the most common document tasks.
How Page Order Works
Papyrio merges files in the order you upload them. File 1 becomes the first section, File 2 follows, and so on. Within each file, pages appear in their original order. Plan your upload order before you start — uploading all files at once and then trying to adjust isn't supported in the current version.
File and Size Limits
Up to 10 PDF files per merge. Total size across all files: 200 MB. Individual files must be under 50 MB each. For very large merges, break them into batches: merge the first 10, download the result, then merge that output with the next batch.
What Happens to Links and Bookmarks
Internal links within each individual PDF are preserved. Cross-file bookmarks — a link in File 1 that points to a page in File 2 — won't carry over. PDF doesn't have a native concept for cross-file references once files are merged. You can add bookmarks manually in a PDF editor after merging.
Password-Protected Files
Password-protected PDFs can't be merged. Remove the password from each file first using Unlock PDF, then merge the unlocked files.