Merge PDF PDF
Combine several PDFs into one file, in the order you choose.
Merge PDF is a free online tool that combine several PDFs into one file, in the order you choose. It runs entirely in your web browser using pdf-lib, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- pdf-lib
- Settings
- 1
- Works offline
- Yes, after the first visit
About Merge PDF
Merging PDFs is the single most-searched document task on the web, and it is nearly always the same story: a form, a scan and a cover letter that somebody wants as one attachment. The order you add files in is the order they appear — drag them into place before you run it.
How to use it
- Add your files — drag them in, or click to browse. Order matters, so add them in the order you want.
- Set output file name.
- Press "Merge PDFs", then download what comes back.
The one setting
| Setting | What it does | Default |
|---|---|---|
| Output file name | Free text. | merged.pdf |
Under the hood
| Runs on | pdf-lib — builds and rewrites the PDF structure |
| Controls | Output file name |
Questions
Is there a limit on how many PDFs I can merge?
No fixed limit. The practical ceiling is your device's memory, since every document is held in RAM while it is stitched together. A laptop handles a few hundred pages comfortably; a phone will struggle sooner.
Will merging reduce the quality of my PDFs?
No. Pages are copied across intact, with their original fonts, vectors and image data. Nothing is re-encoded or re-compressed, so the output is visually identical to the inputs.
Can I merge a password-protected PDF?
Only if it opens without a password. Files with an owner password (restricting editing) are usually fine; files that need a password to open cannot be read at all until you remove it in a PDF reader first.
Do bookmarks and form fields survive the merge?
Page content, annotations and links survive. Document-level bookmarks (the outline pane) and interactive form fields are not carried across — if you need those, merge in a full PDF editor instead.