PDF Tools
Merge PDF
Combine two or more PDF files into a single document, in whatever order you choose. Everything happens inside your browser, so your files are never uploaded.
Your file and options
Add your files, set the order, and merge. Nothing leaves your device.
This tool runs entirely inside your browser. Your file is never uploaded, never stored, and disappears when you close the page.
Result
Add at least two PDFs to enable merging. The finished file downloads automatically.
About this calculator
This tool combines several PDF files into one document, in whatever order you choose. Everything happens inside your browser, so the files you upload are never sent to a server, never stored, and disappear the moment you close the page.
How to use it
- 1.Choose the PDF files you want to combine — add them one batch at a time if you like.
- 2.Use the arrows to put the files in the order you want them to appear.
- 3.Select Merge PDFs; the combined file downloads straight to your device.
Good to know
Pages are copied exactly as they are, so page sizes, text and images are preserved rather than re-rendered.
Password-protected files cannot be read directly — remove the password first with the Unlock PDF tool.
How it works in plain English
You start by choosing the PDF files you want to combine. They appear as a list that you can reorder by dragging, so the final document reads in whatever sequence makes sense, whether that is chapters, chapters, invoices by date, or a cover page followed by supporting attachments.
Once you confirm the order, the tool reads each file and copies its pages, one by one, into a new combined PDF. This work is done using JavaScript and WebAssembly running locally on your device, the same technology that lets a browser render video or edit images without a server in the background. No file ever leaves your computer during this process.
Each page keeps its original content, formatting, and page size exactly as it was in the source file, so a mix of portrait and landscape pages, or letter and A4 sizes, stays intact rather than being stretched or cropped to match. When the merge finishes, you download a single new PDF and the tool discards everything it worked with, leaving no copy behind.
Worked example
Imagine you have three separate PDFs: a signed cover letter, a two-page resume, and a one-page reference list, and you need to send them as a single attachment. You upload all three, then drag the resume to the top, followed by the cover letter, then the references, since that is the order the recipient asked for.
After confirming the order, the tool stitches all the pages together into one four-page PDF, preserving the original fonts, images, and layout of each source document. You download the merged file, attach it to your email, and close the tab. Nothing about the three original files or the merged result stays anywhere except on your own device.
What is preserved when merging PDFs
| Element | Preserved after merge? |
|---|---|
| Page content and formatting | Yes, copied as-is from each source file |
| Page size and orientation | Yes, kept per page, not forced to match |
| Selectable text and links | Yes, unless the source page was already an image |
| File order | Follows the order you set before merging |
| Original files | Untouched; the merge creates a brand-new file |
General behavior of browser-based PDF merging
Frequently asked questions
Are my files uploaded to a server when I merge them?
No. The merging happens entirely inside your browser using JavaScript and WebAssembly, so your files never leave your device. There is no upload step, no server-side storage, and no account required. Once you close the tab, both the original files and the merged result are gone unless you saved a copy yourself.
How many PDF files can I merge at once?
There is no hard limit built into the merging logic itself; you can add as many files as you like and reorder them freely. In practice, very large numbers of files or extremely large PDFs will be limited by your device's available memory, since everything is processed locally rather than on a remote server.
Will merging change how my pages look?
No. Each page is copied with its original content and dimensions intact, so mixed page sizes or orientations stay exactly as they were in the source files. The tool does not resize, rotate, or compress pages during a merge, so text stays sharp and selectable, and image quality is unaffected.
Can I change the order of pages after uploading the files?
Yes. Before you start the merge, the files are shown as a reorderable list, and you can drag them into whatever sequence you need. The final combined PDF follows that order exactly, page by page, so you can put a cover page first or arrange documents by date without editing each file separately.
Does merging remove password protection or watermarks?
No, this tool does not strip passwords or edit content within pages. If a source PDF is password protected, it generally needs to be unlocked before it can be read and merged. Watermarks, stamps, or other content already baked into a page will carry over into the merged file unchanged.
Related PDF tools
Pull out a page range or split every page into its own file.
Shrink a large PDF by lowering page image quality and resolution.
Turn every page or selected pages by 90, 180 or 270 degrees.
Remove pages you do not need and move the rest into a new order.