Your files never leave this device — 100% in-browser

Merge PDF Files

Combine PDFs into a single document, in the order you selected them — entirely on your device.

Select your PDFs in the order you want them combined and drop them below — each drop becomes one merged document, assembled in your browser with pdf-lib. Contracts, invoices and scans never leave your machine, which for documents is the entire point.

Last verified 2026-08-15 — this tool passed 85 automated end-to-end checks

Drop PDFs here in order, or click to browse
converts to PDF · each drop = one merged document
01 — DOCUMENTS STAY HOME
PDFs are the files people least want on a stranger's server: contracts, medical records, IDs. Merging happens entirely in this tab.
02 — ORDER PRESERVED
Pages arrive in the exact order you selected the files — no re-sorting surprises, no filename-alphabetization tricks.
03 — STRUCTURE KEPT
Pages are copied losslessly at the object level, not re-rendered — text stays selectable, links keep working, quality is untouched.

How to use

  1. Drop your file(s) into the box above — or click it to browse.
  2. Conversion starts immediately — no settings needed.
  3. Click Download on each finished file — or Download all (.zip) for a batch. Nothing was uploaded at any point.

How merging works without a server

A PDF is a container of numbered objects — pages, fonts, images. Merging copies those objects from each source into a fresh document, in order, without rasterizing anything: text remains real text, vector graphics stay vector, and file size stays proportional to the inputs. This runs on pdf-lib compiled to plain JavaScript, so the whole operation happens in browser memory and the merged file exists only on your machine until you save it.

Selection order = page order. To control ordering precisely, use the file picker and click files in sequence (or drag a sorted selection). Need several merged documents? Each separate drop produces its own merge.

Merge behavior
PropertyBehavior
Page orderExactly your selection order
QualityLossless object copy — no re-rendering
Text & linksStay selectable and clickable
Limits100 MB per file · 500 pages total
Encrypted PDFsRejected with a clear message

When NOT to merge

  • Password-protected PDFs — encrypted documents can't be read without the password; decrypt them in their native app first.
  • When recipients need individual files — some portals require separate uploads per document; keep the originals.
  • Giant scans — merging 400 MB of scans strains browser memory; the per-file cap here is 100 MB for that reason.

Frequently asked questions

Is anything uploaded?

No. The merge runs in your browser via pdf-lib (open source, MIT). The network tab shows zero upload requests — the standard claim on this site, and for PDFs the one that matters most.

How do I control the page order?

Files merge in selection order. Pick them one by one in the file dialog in the sequence you want, or drop an ordered selection.

Does merging reduce quality?

No — pages are copied structurally, not re-rendered. The output is the sum of its inputs, byte-for-byte where possible.