PDF Merger

pdf + pdf

Combine several PDF files into one document, in the order you set. Your browser builds the file, so it never leaves your device.

QueueNothing is uploaded

Drop PDF files here

or click to choose them

Merging PDFs…

About this PDF merger

This tool combines PDF files into a single document using pdf-lib. It copies every page from each file across in full, so text stays text, embedded fonts and images keep their original quality, and each page keeps its own size and orientation.

Files merge in the order they sit in the queue, and every page of one file is added before the next file begins.

How to use it

01

Add your PDFs

Drop files on the box above, or click the dropzone to choose them. Add as many as you need.

02

Set the order

Drag a row to move it, or use the up and down arrows. Files merge top to bottom.

03

Merge

Click Merge PDFs. Every page of every file copies across in that order.

04

Save the file

The merged PDF appears with a Download button. It reaches your device only when you click it.

What it does

  • Your browser merges the files with pdf-lib, and no request carries them to a server.
  • Pages are copied, not redrawn, so text stays searchable and image quality doesn't drop.
  • Each page keeps its own size and orientation, so mixed A4 and Letter files don't get stretched to match.
  • Drag and drop, or the up and down arrows, set the merge order before you combine.
  • There's no fixed limit on how many files you add, only on the size of each one.

Specifications

Specification Details
Accepts PDF files, several at a time
Output One merged PDF, all pages included
Page order Files merge in queue order; every page of a file stays together
What's kept Text, fonts, images and vector graphics, copied without re-encoding
What's dropped Bookmarks and the document outline; form fields may stop working as fields
File size limit 100 MB per file. There's no cap on how many you add.
Library pdf-lib 1.17, loaded from the cdnjs CDN
Good to know

What it does not do

It appends whole files together in order. Some jobs need a different tool.

No password-protected files

A file that needs a password to open fails the merge instead of being skipped. Remove the password in the app that created it and try again.

No page selection

Every page of every file is included. There's no way to drop or reorder individual pages from inside one file before merging.

No bookmarks

The merged file starts with no navigation outline, even if the source files had one.

No compression

Merging only copies pages, so the result is roughly the size of the files added together. There's no way to shrink it inside this tool.

Related PDF tools

Images to PDF Combine photos or scans into one ordered document. PDF cropper Drag a crop box or type exact margins in pt, mm or in. PDF to images Render each page as a png or jpg image. DOCX to PDF Fixed-layout PDF from a Word file, without Word.
All document tools → What merging keeps and drops, in detail →

Frequently asked questions

No. pdf-lib runs in this tab and merges the files you added. The only download is the pdf-lib library itself, from the cdnjs CDN, and no request carries your documents.

Bookmarks and the document outline aren't copied, so the merged file starts with no navigation tree. Interactive form fields may stop behaving as fields, so fill them in and flatten them first if you need to keep them working.

No. A file that needs a password fails the merge with an error rather than being silently skipped. Remove the password first.

You can reorder whole files by dragging them or using the up and down arrows. There's no way to drop or reorder individual pages from inside one file.

Roughly the size of the source files added together, since merging copies pages rather than compressing anything.

Each file can be up to 100 MB. There's no cap on how many you add.

Your files stay on your device

Your browser merges the PDFs with pdf-lib inside this tab. Nothing is uploaded, and closing the tab clears the files from memory.