Merge PDF

How to merge PDF files

1. Choose or drop all your PDFs at once. In the file dialog, hold Ctrl (Cmd on a Mac) to select several files, or drag them onto the box together. JPG and PNG images can go in the same batch; each one becomes a page.
2. Check the order. Files are joined in file-name order, A to Z, with numbers sorted the way people expect: chapter 2 comes before chapter 10. Choose Z → A to reverse it.
3. Download the merged PDF. The result also lists your files with numbers, for a custom order (below).

Custom order and page selection

Write the file numbers in the order you want, separated by commas. To take only part of a file, put a colon after its number and then the pages, and separate such parts with semicolons. Pages work like a print dialog: a dash for a range, commas between ranges, and an open end such as 4- for "page 4 to the last page".

A file can appear more than once, and files you don't mention are left out. If a number doesn't exist — file 4 when you chose three files, or page 12 of a 10-page file — the tool says so instead of guessing.

How merging works

Each PDF page points to its content (the drawing instructions for text and graphics) and to the fonts and images it uses. The merger reads every file with pdf-lib, an open-source PDF library running inside your browser, and copies each page with everything it references into one new document. Nothing is re-rendered or re-compressed: text stays sharp and selectable, images keep their quality, and every page keeps its own size and orientation — a US Letter page next to an A4 page stays as it was.

Each added image is turned upright (using the rotation your phone stored in the photo) and placed on a page shaped like the picture, its long side as long as an A4 page. For other page sizes and margins, convert photos with JPG to PDF first.

Worked example

A job application asks for a single PDF. You have cover-letter.pdf (1 page), resume.pdf (2 pages) and transcript.pdf (4 pages, of which only the first two are needed). In A → Z order the list reads: 1 cover-letter, 2 resume, 3 transcript. Typing 1, 2; 3: 1-2 produces a 5-page PDF — the cover letter, both resume pages and the first two transcript pages — saved as cover-letter-merged.pdf.

Your files stay on your device

Most online PDF tools upload your documents to a server, process them there and promise to delete them later. Here your browser does the merging on your own computer or phone, and the files are never sent anywhere. That matters for the documents people combine most often — signed contracts, tax returns, bank statements, scans of passports and driver's licenses, medical records. Once a copy sits on someone else's server, you no longer control who sees it or how long it stays there.

Limits: what doesn't carry over

• Protected PDFs: a file with a password, or one locked against changes, can't be merged — the tool names it and stops rather than produce broken pages. Open it in your PDF reader, enter the password if asked, print it to a new PDF ("Save as PDF" or "Microsoft Print to PDF") and merge that copy.
• Bookmarks, forms and links: sidebar bookmarks aren't copied, and form fields keep what was typed into them but are no longer fillable — fill in forms before merging. Web links keep working; links to another page of the same document don't.
• Scanned documents stay pictures of text: merging doesn't make them searchable.
• Very large files: everything is held in your device's memory — in our test, merging 87.5 MB of PDFs took about 0.5 GB — so on a phone keep batches smaller. The tool warns when the files add up to more than 100 MB.

The merged file is about as large as the originals put together; for a smaller PDF of photos, shrink them first with the image compressor. To take a PDF apart, use Split PDF; to drop a few pages, Delete Pages from PDF.

Frequently asked questions

Last updated: October 15, 2026