Combine two or more PDF files into one, in your browser, with pdf-lib. Sensitive documents never leave your device.
Files are merged in the order shown. Everything is combined in your browser with pdf-lib — nothing is uploaded.
How to merge PDFs
Select two or more PDF files. They appear in a list you can trim with the × button, then press Merge into one PDF. The combined file downloads instantly.
Why do it here?
Because the documents never leave your computer. Contracts, statements, signed forms — anything sensitive — is merged locally and handed back as one PDF.
Frequently asked questions
Is there a page limit?
The work runs on your device, so very large PDFs are limited by the memory your browser has free. For normal documents this is not noticeable.
Are the files uploaded?
No. The merge is performed in the page with an inlined library; the files are read locally and discarded when you leave the tab.
Can I reorder pages?
You can reorder whole files by removing and re-adding them. For precise page-level reordering, split then re-merge.
How to use it
- Pick two or more PDF files from your computer. They appear in a vertical list.
- Remove any file you do not want by clicking the × button next to it. The order shown is the order the pages will be merged.
- Press Merge into one PDF. The browser reads each file with pdf-lib and joins the page streams.
- A new PDF downloads automatically. Open it to check the order and page count.
Where it comes in handy
A landlord sent three separate PDFs of a one-year lease addendum, an inspection report, and the signed disclosure. Together they total about 4.2 MB. Merging them into a single 6.8 MB PDF meant the tenant received one file instead of three attachments that had to be sorted manually.
An accountant needs a client’s W-2, 1099, and K-1 combined for tax season. Each form is roughly 150 KB. After merging, the single package fits comfortably inside most email attachment limits, which cap at 25 MB, leaving plenty of headroom for future documents.
A university admissions office receives 12 individual PDF transcripts from different high schools, each containing 3 to 8 pages. Merging them into batch files lets the reviewer open one document per applicant rather than switching between 12 separate tabs.
Worth knowing
- The merge runs entirely in your browser. No bytes leave your computer, so the tool cannot compensate for large files exceeding your available RAM. On a typical laptop, PDFs under 50 MB each merge without slowing down; above that, expect the page to freeze while the browser allocates memory.
- Page numbers are assigned sequentially as each file is read. If two source PDFs both start at page 1, the combined document will contain duplicate page numbers. The tool does not renumber automatically.
- Embedded bookmarks and hyperlinks from the source files are preserved, but the destination PDF gets a single outline hierarchy. Files merged in the order shown become sequential chapters; cross-file links between documents remain functional only within the same combined PDF.