PDF Merger
Merge multiple PDF files into a single document in the order you choose. Fast and secure.
Drag & drop your PDF here
or click to select file
User Guide
Add your PDFs
Drag them onto the upload area or click to browse, and add up to 20 files. You can add them in several goes — each new drop is appended to the list rather than replacing it, so you do not have to select everything at once.
Check the thumbnails
Every file appears as a row showing the first page, the file name, its size and its page count. That page count is worth a glance: it is the quickest way to spot that you have picked a 200-page draft instead of the two-page final.
Put them in the right order
The numbered badge on each row is its position in the finished document. Drag a row to move it, or use the ↑ and ↓ buttons. The output follows this list from top to bottom — not the order you happened to select the files in.
Remove anything that should not be there
The × button drops a single file without clearing the rest. Removing the last remaining file resets the tool so you can start again.
Press Merge
The merge runs in this browser tab. Nothing is uploaded, so there is no waiting on a connection — the time it takes depends on your device and the total page count, not on your upload speed.
Download and check the joins
Open the result and look at the points where one document ends and the next begins. That is where an ordering mistake shows up, and it is far quicker than reading the whole file.
About the Merge PDF Tool
This tool joins up to 20 PDF files into one document, in an order you control, entirely inside your browser. Nothing is uploaded to a server at any point.
How merging actually works
A PDF is a container: a set of page objects plus the fonts, images and metadata they refer to. Merging copies the page objects out of each source file and writes them into a single new document, carrying their resources with them.
Because the pages are copied rather than re-rendered, nothing is re-compressed and no quality is lost. Text stays selectable and searchable, vector graphics stay sharp at any zoom, and an image that was 300 DPI in the source is still 300 DPI in the result. A merged file is normally close to the sum of its inputs, minus a little where the files shared fonts that only need storing once.
Order is the part people get wrong
The single most common mistake is assuming files merge in the order you picked them. They do not — browsers hand over multi-file selections in whatever order the operating system returns, which is often alphabetical, sometimes by date, and occasionally neither.
That is why every file here is a row you can move. The numbered badge is the position in the finished document, and the list is the single source of truth:
| To do this | Use |
|---|---|
| Move one file up or down | The ↑ and ↓ buttons on its row |
| Move a file several places | Drag the row where you want it |
| Drop a file from the merge | The × button |
| Confirm what a file is | Its first-page thumbnail and page count |
A practical habit for documents that must be assembled in a fixed sequence — tender submissions, application packs, court bundles: name the files 01-cover.pdf, 02-form.pdf, 03-annexure.pdf before you add them. Zero-padded numbers sort correctly, and the list will usually be right the moment they load.
Processed in your browser, not on a server
The merge is performed by JavaScript running on this page. Your files are read from disk into the tab’s memory, combined there, and written straight back out as a download. They are never transmitted, which has four consequences worth knowing:
| What it means here | |
|---|---|
| Privacy | Confidential documents never leave the device — there is no copy on any server to be retained or leaked |
| Speed | No upload and no download of the result; a large merge is bounded by your processor, not your connection |
| File size | No server-side upload cap applies. The practical limit is your device’s memory |
| Offline | Once the page has loaded, the merge itself needs no internet connection |
What the limits really are
The tool accepts 20 files per merge. Beyond that the ordering list stops being something a person can usefully manage, and it is faster to merge in two passes and then merge the results.
There is no fixed megabyte ceiling, because there is no upload to constrain. What limits you is memory: every file is held open while its pages are copied. A few hundred pages of ordinary text documents is unremarkable on any modern phone or laptop. Hundreds of pages of high-resolution scans is a different matter — if a merge stalls or the tab reloads, that is the browser running out of memory, and the fix is to merge in smaller batches.
Encrypted and damaged files
A password-protected PDF cannot be merged while it is still encrypted — its pages are unreadable until the password is supplied. Remove the protection first with the Unlock PDF tool, then merge the result.
If a file fails to produce a thumbnail, it is usually either encrypted or structurally damaged. The row still appears so you can remove it, but it is worth opening that file on its own before assuming the merge will succeed.
After merging
If the result needs to be smaller, run it through the PDF Compressor. To pull specific pages back out, use Split PDF. To reorder or delete pages within the merged file rather than whole documents, Organize PDF works page by page. To add page numbers across the combined document, use Add Page Numbers — and do it after merging, or the numbering restarts at each original file.
Frequently Asked Questions
How many PDF files can I merge at once?
Up to 20 files in a single merge. You can add them in several goes rather than selecting them all at once — each new drop is added to the list. For more than 20, merge in batches and then merge the results together.
Will the files merge in the order I selected them?
No, and this is the most common surprise. Browsers hand over multi-file selections in whatever order the operating system returns, often alphabetical. The list on the page is what decides the output — drag rows or use the arrow buttons to set the order you want.
How do I change the order after adding files?
Drag a row to move it several places, or use the up and down arrows on the row to move it one step. The numbered badge always shows that file’s position in the finished document.
Does merging reduce the quality of my PDFs?
No. Pages are copied from the source files rather than re-rendered, so nothing is re-compressed. Text stays selectable, vector graphics stay sharp and image resolution is unchanged. The merged file is usually close to the sum of the originals.
Are my files uploaded to a server?
No. The merge runs in your browser — files are read from your disk into the page’s memory, combined there and written back out as a download. Nothing is transmitted, so there is no copy on any server.
Is there a file size limit?
There is no upload limit, because there is no upload. The practical constraint is your device’s memory, since each file is held open while its pages are copied. If a very large merge stalls or the tab reloads, split it into smaller batches.
Why does one of my files show no thumbnail?
Almost always because it is password-protected or damaged. Encrypted PDFs cannot be read until the password is removed — use the Unlock PDF tool first. The row still appears so you can remove that file from the list.
Can I merge a Word document or images along with PDFs?
Not directly — this tool takes PDFs. Convert first: use Word to PDF for documents, or the JPG to PDF converter for images, then add the resulting PDFs to the merge.
