Merge PDF

Join up to 10 PDFs into one file, in the order you choose.

Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.

Your files

Drop PDF files here, or click to browse. Add up to 10 files, 50 MB in total. Everything is processed on this device only — no file is uploaded.

Merge PDFs Clear file list

Files are merged in the order shown. Use the Up and Down buttons on a row to change its position before merging.

Think of Merge PDF as building a single packet out of loose documents. You bring up to ten PDFs, stack them in the sequence you want a reader to meet them, and the tool binds those pages into one new file. Classic cases: a form that a scanner delivered in three separate pieces, a monthly report whose appendix came out of a different program, or signed sheets that should travel together as one tidy attachment rather than a handful of separate files.

Nothing inside the pages gets altered along the way — no editing, no shrinking, no watermarks, and no account stands between you and the download. What changes is only the packaging: many files become one. Your documents never leave this machine while that happens. The joining runs locally, inside the tab's memory, using code delivered alongside the page itself; the finished download is the sole copy the process creates, and shutting the tab discards the working material entirely.

How to use Merge PDF

1. Start with the first document. Drag a PDF in, or click the dropzone and pick one from your folders. You may gather as many as 10 files provided they add up to no more than 50 MB, and each candidate is inspected the moment it arrives — a broken file, or one that asks for a password, is called out by name straight away.
2. Glance at what you have collected. The list spells out every entry's name, byte size and length in pages, letting you confirm the right documents were grabbed and estimate how long the bound packet will run.
3. Stack the list in reading order. Position in the list is position in the finished file. Nudge an entry with its Up or Down button; whatever sits at the top opens the packet, and the entry at the bottom closes it.
4. Prune a mistaken pick. Hit Remove on any row that should not be there. That drops the entry from this session only — the file sitting on your device stays exactly where it was, untouched.
5. Press Merge PDFs. Working down the list from top to bottom, the tool transplants every page of every document into a fresh PDF, then hands that file to your browser as a download the instant assembly finishes.
6. Flip through the seams. Look where one source ends and the next begins: the final sheet of the earlier document should be followed immediately by the opening sheet of its successor. Wrong sequence? Shuffle the list and assemble again; the sources have not changed, so a second attempt costs you nothing but a click.

Features

• Binds as many as 10 PDFs in a single pass, with a combined ceiling of 50 MB that is checked before any page is touched.
• Pages move across at the object level instead of being redrawn, which is why searchable text remains searchable, photographs stay at the sharpness they arrived with, and a sideways sheet keeps its sideways orientation.
• Every row advertises its page count before you commit, and the status line announces the grand total once the packet is built.
• Reordering buttons are fully operable from the keyboard and announce themselves properly to assistive technology; each row can also be dropped on its own.
• A file that cannot be opened — encrypted, damaged, or not a PDF at all — stops the job with its name attached to the explanation, rather than letting the run collapse mysteriously midway.
• The download borrows the name of whichever document sits first in the list and appends “-merged”, so it lands beside its ingredients instead of overwriting any of them.

Worked example

Imagine three documents on your desk: letter.pdf, a covering letter of two pages; report.pdf, which runs to three pages; and form.pdf, a signed form occupying a single page. Place them in that sequence and the list reports 2, 3 and 1 — six pages altogether.

Run the merge and your browser delivers letter-merged.pdf, a document with six pages arranged like this: both pages of the letter, followed by all three pages of the report, followed by the lone form page. The automated tests behind this page build precisely that arrangement out of labelled fixture files — documents containing 2, 3 and 1 pages — and check that the finished sequence of page markers reads 1, 2 from the opening file, then 1, 2, 3 from the middle file, then 1 from the closing file. In other words, the evidence confirms that list position governs the outcome, not alphabetical order or file size.

Swap the stacking — report.pdf lifted above letter.pdf — and assemble a second time, and those same six pages emerge with the report leading and the letter behind it. The pages themselves are identical; only their company has changed.

Common errors and limitations

• Ceilings for one pass: 10 documents, 50 MB combined. Anything bigger has to be bound in stages — assemble one group, then feed that result back in alongside the next group.
• Locked files halt the job before it starts. Because the joining library cannot decrypt a document, any protected entry is named and turned away; unlock it in the program that produced it and bring the open copy back instead.
• File size does not go down here. Since sheets move across unaltered, expect the packet to weigh roughly what its ingredients weighed added together; run a compressor over it afterwards if bulk is a problem.
• Interactive elements ride along as found — form fields and annotations are transplanted, not reworked — and be aware that folding a digitally signed document into a larger file can break the validity of its signature, as it can in any editor.
• Exotic containers sit outside the job description. A portfolio PDF, which is really a bundle of separate files wearing one cover, may be turned away as unreadable rather than dismantled.

• Letting the selection order become the reading order. Documents bind in the sequence shown on screen, and the sequence in which you happened to click them in a folder dialog is seldom the sequence a reader needs. Scan the list from top to bottom as if it were a contents page, because that is precisely what it predicts, and promote or demote rows until it reads correctly.
• Waiting for a password prompt that never comes. This page deliberately never asks for one. When a protected document appears in the list, it will be turned away by name at merge time; the remedy is to open it elsewhere, export a copy that opens freely, and substitute that copy.
• Budgeting for a smaller download than you will get. Binding is copying, not compressing. Five sources of roughly 4 MB each yield a packet in the neighbourhood of 20 MB, so if a mail system caps attachments below that, compress the merged result rather than hunting for a size setting that this page does not have.
• Reporting the output as lost. Nothing was sent anywhere, so there is no remote copy to retrieve. Search your downloads folder for the file whose name ends in “-merged” — that folder is the only place the packet was ever placed.

Frequently asked questions

Related PDF tools

Prefer everything on one page? The original PDF Toolkit merges, splits and rearranges with one shared file list. The full suite is indexed on the PDF Tools hub.

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