Merge PDF files online

Merge PDF files right in the browser: drop the first PDF, click Merge, pick the second file, and its pages are appended to the end of the first. Nothing is uploaded, and the combined document is written on your device when you click Download.

How to merge PDF files step by step

The viewer works on one document at a time, so merging is a matter of opening the file that should come first and adding the others after it. Order matters: whatever you open first stays at the front.

1. Drop the PDF that should come first into the box above, or click Open a PDF on the home page.
2. Click Merge in the toolbar and pick the second PDF from your computer.
3. The second file's pages appear after the last page of the first. Check the thumbnail sidebar to confirm.
4. Repeat Merge for a third, fourth or tenth file. Each one is appended to the end.
5. Rotate, delete or drag pages in the sidebar if the order needs fixing, then click Download.

The download is a fresh PDF with every page from every file. The originals on your disk are not touched. If you want the step-by-step version with screenshots of each stage, see how to merge PDF files.

What the merged PDF looks like in other readers

The result is a standard PDF written by pdf-lib, so Adobe Acrobat, Preview, Chrome, Edge and phone readers open it like any other file. Pages keep their own size and orientation: a landscape slide deck appended to a portrait letter will show mixed page sizes, exactly as it would in Acrobat's combine tool.

Highlights, drawings and text you added before merging are embedded in the download as well. Bookmarks and outlines from the source files are not something the viewer promises to carry over, so if a long report depends on its table of contents, check it after merging.

Limits: merge appends to the end

A few things to know before you start, so you are not surprised halfway through a large job:

• Append only. The second file always lands after the last page of the current document. There is no "insert at page 5" option. The workaround is to merge first and then drag pages into place in the sidebar, which is covered on reorder PDF pages.
• No split or extract. The viewer merges but does not cut a page range into a separate file. The practical route is to delete the pages you do not want and download; for real splitting tools see split PDF.
• Password-protected files. A PDF that asks for a password to open cannot be opened or merged. Remove the password elsewhere first, as explained in remove password from PDF.
• Memory. There is no file-size cap in the code, but everything lives in the browser tab. Merging several hundred-page scans on a phone can run out of memory; a laptop handles typical office documents without trouble.

Other ways to combine PDF files

If you need insertion at a specific page, bookmark merging or batch jobs on a folder, one of these does it:

The upload caveat is the reason many people prefer a browser-side merge for contracts, medical records and anything with a client's name on it. The viewer never sends the file anywhere; see privacy for the details.

Merging scans, signed pages and forms

Three kinds of input deserve a note, because they behave a little differently once combined.

• Scanned PDFs. Pages of a scan are images, so the merged file is only searchable where a text layer exists. Run OCR on the combined document after merging if you need Ctrl+F across all of it; doing it once on the final file is simpler than doing it per source.
• Signed documents. A signature drawn in the viewer is an image annotation and survives the merge. A certificate-based digital signature from Acrobat or DocuSign is tied to the exact bytes of the original file, so any merge, in any tool, invalidates it. Keep the signed original and merge a copy.
• Forms. Fillable fields are shown but not editable here, and merging two forms with fields of the same name can confuse other readers. If you only need the filled form as a record, print it to PDF first so the fields become flat content.

A practical habit: name the source files 01-cover.pdf, 02-body.pdf, 03-appendix.pdf before you start. The file picker lists them in order and you will not have to reshuffle pages afterwards.

Frequently asked questions