Merge PDF Files
File ToolsCombine PDFs in the order you choose — in your browser, never uploaded.
Your files never leave this device. Everything here runs in your browser — your files are never uploaded, stored or seen by us. Open your network tab and check.
Add two or more PDFs. They merge in the order you arrange them here.
How this is calculated
Merged pages = pages(file 1) + pages(file 2) + ... + pages(file n) Order = the order you arrange them in, exactly Output = one rebuilt document, source metadata removed Nothing is uploaded. The merge runs in this browser tab.
How it works
A PDF is a container: a set of page objects plus the fonts, images and metadata they refer to. Merging copies every page object out of each source document, along with the resources that page depends on, into one new container. Nothing is re-encoded, so the text stays selectable and the images keep the quality they already had.
There is no compression step, and there should not be — you asked to combine documents, not to change them. So a merged file lands close to the sum of its parts. It can come out a little smaller, because rebuilding the container drops metadata and any resource the sources shared, such as a font both of them embedded; it will not shrink the way a compressor shrinks things. If the result is larger than you need, run it through the PDF compressor afterwards, which is a separate decision with a visible trade-off.
The merge happens entirely in your browser using pdf-lib. Your files are read into memory by this page, combined, and offered back as a download. They are never sent anywhere, which matters more here than on most file tools: the documents people merge are bank statements, signed contracts, medical records and ID scans for applications.
Order is yours to set. Files are merged exactly as you arrange them, not sorted by name or by the order your operating system happened to hand them over. Getting this wrong is the one merge error that produces a file which looks fine and is not, so it is a visible control rather than an assumption.
Worked example
Three documents combined for a rental application
- id-proof.pdf 2 pages
- salary-slips.pdf 6 pages
- bank-statement.pdf 12 pages
- --------
- merged.pdf 20 pages, in that order
One 20-page PDF, with the source titles and authors stripped
How to use it
- Drop your PDFs onto the panel, or choose them from your device. You can add more in a second drop — new files are appended, not swapped in.
- Check the page count shown against each file. If a file will not open, it is flagged before you merge rather than after.
- Use the arrows to set the order. Files merge top to bottom, exactly as listed.
- Press Merge, then download the result. Nothing is uploaded at any point.
- If the merged file is bigger than you need, run it through the PDF compressor.
What this tool does not do
- Password-protected PDFs cannot be merged. They will load but refuse to copy, and the tool says which file is the problem rather than failing silently.
- The merged file is not compressed. It is roughly the sum of its sources, because merging does not re-encode anything.
- Bookmarks, form fields, annotations and digital signatures are not carried across. Pages, text and images are.
- Twenty files at a time. This runs in your browser, so very large batches are limited by your device's memory, not by a server quota.
- Page order within a single file is preserved as-is. To reorder or remove individual pages, split the file first.
Frequently asked questions
Are my files uploaded anywhere?
No. The merge runs in your browser using pdf-lib, and no network request carries your file. You can verify it: open your browser's network tab before merging and watch that none of them does — the only requests you will see after the page loads are small ones recording that the tool was used. That is the difference between this and most merge tools, which post your documents to a server.
Is there a file size or page limit?
No server limit, because there is no server. The practical ceiling is your device's memory — a phone will manage a few hundred pages comfortably, a laptop far more. The tool accepts up to 20 files at once.
Can I merge a password-protected PDF?
Not directly. An encrypted file will open for reading but refuses to have its pages copied, and you will see a message naming the file. Remove the password in your PDF reader first, then merge.
Why is the merged file so large?
Because merging does not compress. Every page is copied across without re-encoding, so the output lands near the sum of the inputs — sometimes a little under, since rebuilding drops metadata and any font or image the sources shared. That is deliberate: combining documents should not quietly degrade them. Use the PDF compressor afterwards if you need it smaller.
Does it keep bookmarks and form fields?
No. Pages, text, fonts and images are copied. Bookmarks, interactive form fields, annotations and digital signatures are not carried across, and a signature would be invalidated by the merge in any case.
How do I change the order?
Use the up and down arrows beside each file. Documents merge exactly top to bottom as listed — nothing is sorted by filename behind your back, because a merge in the wrong order produces a file that looks correct and is not.
What happens to the document properties?
Title, author, subject, keywords, producer and creator are cleared on the merged file. A merge usually combines documents from different sources, and inheriting one file's author for all of them is a privacy leak most people would not expect.
Can I merge images into a PDF here?
Not with this tool — it takes PDFs only. Use the image to PDF tool for photos and scans, then merge the result with your other documents if you need to.
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Last updated 6 September 2026.