Nothing is uploaded, and you can check that
Every large PDF site sends your file to a server, works on it there, and sends it back. iLovePDF keeps files for two hours across a fleet of more than a hundred machines. Smallpdf keeps them an hour if you have an account, and vaguer than that if you do not.
That may be fine for a holiday itinerary. It is a strange thing to accept for a signed contract, a scan of a passport, a set of payslips or a medical letter, which is a fair description of what most people actually merge.
This runs on the page, using your own machine. The file never goes anywhere. Open your browser's network tab and merge something: nothing leaves. It also works with the internet unplugged.
No limits, because there is nothing to meter
No cap on how many files, no maximum size, no daily quota, no watermark and no account.
The reason those limits exist elsewhere is that server time costs money, so somebody has to ration it. iLovePDF caps anonymous users at 25 files and, on conversions, at a single file per go. Here the work happens on your machine, which costs us nothing, so there is nothing to ration.
How this tool works
Each file you drop in is opened in the page and read for its page count, which is why the list fills in as you go rather than after you press anything. The engine downloads on the first file, not on page load, so opening this page costs nothing.
When you merge, the pages are copied as whole objects into a new document, in the order shown on screen, and the new document is handed straight to your browser as a download. Nothing is re-encoded and nothing is drawn again, which is why it is close to instant even on a few hundred pages and why the quality question below has the answer it does.
Your original files are never touched. The merge writes a new document and leaves everything you dropped in exactly as it was.
Merging does not lose quality
A common worry, and the answer is no, provided the tool does it properly. Pages here are copied across as whole objects: the text stays real text, so it is still selectable and searchable, links still work, and vector drawings stay sharp at any zoom.
What does destroy quality is any tool that rasterises pages, turning each one into a picture before combining them. That kills the text layer permanently, bloats the file, and makes the result useless for anything that needs searching or copying. If you have ever merged a PDF and found you could no longer select the text, that is what happened.
The order is the order on screen
Drag files up and down and that is the order they come out in. Worth checking before you press the button, because most people drop a folder in and the browser hands them over alphabetically, which puts "Appendix" before "Introduction".
Taking only part of a file
Type a page range against any file and only those pages are used. The format is forgiving on purpose, because this gets typed in a hurry:
1-3, 5, 8-10takes pages one to three, five, and eight to ten.8-endtakes everything from page eight.3,1,2takes three pages and reorders them as it goes.1,1,1gives you three copies of page one, because listing the same page twice is allowed and that is a perfectly reasonable way to ask for three copies of a cover sheet.
A number that does not exist in the file is simply skipped rather than throwing the whole thing away, so one typo does not lose a long list.
Password protected files
There are two kinds of PDF password and only one is a problem.
A permissions password restricts printing or editing while leaving the document readable. Those merge fine. An open password means the file's contents are genuinely encrypted, and nothing can read it without the password, including this. Open it in your normal PDF reader, save an unlocked copy, and merge that.
The set you are merging is the set you do not want scattered
The files stay on your machine and are discarded when you close the tab. There is no account, no sign up, nothing uploaded and nothing logged.
Merging is where that matters in a way people do not expect. One file on its own is usually innocuous; the set you are joining together is a tender, a handover pack or an application, and what makes it sensitive is the assembly rather than any one page. Uploading it hands somebody the finished picture rather than a fragment.
Common questions
Is this PDF merger really free?
Yes. No account, no email, no watermark, and no limit on how many files or how large they are. The merging happens in your browser rather than on a server, so there is no cost to us and nothing to meter.
Are my files uploaded anywhere?
No. The whole thing runs on the page using your own machine. You can check it: open your browser network tab and merge something, and you will see no request go out. It also works with the internet disconnected.
Does merging reduce the quality of my PDF?
No. Pages are copied across whole, so text stays selectable and searchable, links keep working and vector graphics stay sharp at any zoom. Tools that flatten pages to images to merge them do lose that, permanently.
Can I merge only some pages from a file?
Yes. Type a range against any file, like 1-3, 5, 8-end. Leave it blank to take every page. You can also list pages out of order, such as 3,1,2, to reorder as you merge.
How many PDFs can I merge at once?
As many as you like. There is no file count limit and no size limit beyond what your own browser can hold in memory. Most free merging tools cap this at two to twenty files unless you pay.
Can I merge a password protected PDF?
Only if the password restricts editing or printing rather than opening. A PDF that needs a password just to open cannot be read without it. Open it in your PDF reader, save an unlocked copy, then merge that.