Do bookmarks and the table of contents survive the merge?

No. The pages come across with their text, images and links, but the document outline is a structure above the pages and is not carried, so a merged file has no bookmarks even if one source had them. For labels, manifests and invoices that costs you nothing; for a catalogue with a contents tree, expect to rebuild it.

What happens to a fillable form?

The pages look right, but the form wiring lives at document level and is not merged, so fields that were fillable usually stop accepting input. If you need a form to stay fillable, fill it in first and merge the finished copy afterwards.

How many files can it take, and how big?

There is no fixed limit, because there is no server to set one. The whole job happens inside your browser tab, so the tab's memory is the ceiling - a few hundred pages of labels is routine, while a 400 MB scanned catalogue on an old phone may run out. If you are unsure, merge in two goes.

Can I take only part of one file?

Yes, and this is the reason the range box sits on every row rather than at the bottom. A common case is one file contributing pages 1-3 and another contributing everything from page 8, which you can type as 8- without counting to the end.

Is the file sent anywhere to be merged?

No. Every page is read and written by this browser tab, so the customer names, addresses and phone numbers printed on your labels never leave the machine. There is no upload endpoint on our side for a file to go to.

It says my PDF cannot be opened. Why?

Almost always a password-protected file. A PDF locked with an open password has to be unlocked in the program that made it before any browser tool can read the pages, and this one tells you that rather than merging a blank document.

Merge several PDFs into one file

A seller's PDFs arrive in pieces. Labels downloaded at eleven and again at four, a courier manifest from one panel and a pickup sheet from another, ten invoices your accountant wants as one attachment instead of ten. Printing or sending them one by one is exactly where a page goes missing.

This puts them into a single document in an order you set by dragging the list, and each file can contribute only the pages you want: type 1-3, 7 in the box beside it, or press Choose pages and click the thumbnails. Pages are copied across rather than redrawn, so a courier's barcode stays the vector artwork it was in the original.

Open the merge tool Needs an account. The trial is free and takes a WhatsApp code.

How it works

Add every file. Drop the PDFs on the page or press Add PDFs. Add as many as you like, in any order - the sidebar keeps a running count of files, pages in and pages out as you go.
Put them in order. The list is the document: top to bottom becomes first page to last. Drag a file by its handle, or use the up and down arrows on its row.
Trim what you do not need. Beside each file is a page box. Leave it empty to take the whole file, or type something like 1-3, 7, 9-12. Press Choose pages to open that file's thumbnails and click the pages instead of typing them.
Merge and download. Press Merge into one PDF. The output is named after the first file in the list - order-labels-merged.pdf - and the notice tells you how many pages came from how many files.

What it handles

Any number of files, merged top to bottom in the order you drag them
A page range per file, so two overlapping marketplace exports do not both contribute the same pages
Ranges are read loosely: 1-3, 7, 9-12 works, and so do 5 to 9, 8- for everything from page 8 onwards, and a backwards 12-4
Text stays text and barcodes stay vector - pages are copied with their own objects, never re-rendered
Live counts while you work: files added, pages in, pages out, and a warning before an empty merge
Pages taken from the same file share that file's embedded fonts and images, so the merged PDF is smaller than the parts added together
Mixed page sizes are kept - an A4 invoice and a 4x6 label stay their own size inside one document

Your files stay on your computer

This runs inside your browser tab. The file is read and written on your own device and is never uploaded — not the order PDF, not the customer names and addresses printed on it. There is no upload endpoint to send it to.

Questions

Do bookmarks and the table of contents survive the merge?: No. The pages come across with their text, images and links, but the document outline is a structure above the pages and is not carried, so a merged file has no bookmarks even if one source had them. For labels, manifests and invoices that costs you nothing; for a catalogue with a contents tree, expect to rebuild it.
What happens to a fillable form?: The pages look right, but the form wiring lives at document level and is not merged, so fields that were fillable usually stop accepting input. If you need a form to stay fillable, fill it in first and merge the finished copy afterwards.
How many files can it take, and how big?: There is no fixed limit, because there is no server to set one. The whole job happens inside your browser tab, so the tab's memory is the ceiling - a few hundred pages of labels is routine, while a 400 MB scanned catalogue on an old phone may run out. If you are unsure, merge in two goes.
Can I take only part of one file?: Yes, and this is the reason the range box sits on every row rather than at the bottom. A common case is one file contributing pages 1-3 and another contributing everything from page 8, which you can type as 8- without counting to the end.
Is the file sent anywhere to be merged?: No. Every page is read and written by this browser tab, so the customer names, addresses and phone numbers printed on your labels never leave the machine. There is no upload endpoint on our side for a file to go to.
It says my PDF cannot be opened. Why?: Almost always a password-protected file. A PDF locked with an open password has to be unlocked in the program that made it before any browser tool can read the pages, and this one tells you that rather than merging a blank document.

Related tools

Open the merge tool