Merge PDF files in your browser
Merge PDF files when a portal wants one attachment and you still have a contract, an exhibit, and a scan in three separate documents. You set the order, you can drop a blank page between them, and the result is a new PDF. The files stay in this tab.
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or drop / paste
How to merge PDF files
- Add at least two PDFs by dropping them, pasting, or using Choose files. Up to fifty files are accepted in one batch.
- Put them in the order the reader should see. Use the up and down buttons. Mixed page sizes are kept as they are.
- Turn on a blank page between documents when you want a visual break. The blank page matches the size of the previous file.
- Set the output name if you do not want merged.pdf, then press Merge PDFs.
- Download the single file. Page count equals the sum of the inputs, plus any blank pages you asked for.
Merge PDF options explained
The blank-page toggle inserts one empty page after each document except the last. It uses the previous file’s page size, so a letter packet followed by an A4 scan does not force every page onto one size.
Output name is the filename on the download. It does not change the document title inside the PDF. Use Edit PDF metadata afterwards if the portal reads the title field.
Bookmarks and outlines are not copied. The merger builds a new document and copies pages, not the outline tree. If you needed those bookmarks, say so in the filename and keep the originals.
What a merge PDF actually keeps
Each page is copied with its content streams, so text stays selectable and vector lines stay sharp. Rotation, crop boxes, and page size travel with the page. A landscape sheet in the middle of a portrait packet stays landscape.
Form fields are copied when the library can carry them, but a field name that already exists in an earlier file can collide. If you are merging filled forms that must stay editable, flatten each form first, then merge the flat pages.
Encryption is not silently stripped from a file you cannot open. An encrypted input asks for the password you already know. Wrong password stops that file and leaves the others in the list so you can retry.
When a single file is the wrong job
One PDF in the list is allowed, and the result is a copy of that file. The page says so, because the useful next step is usually Organize PDF if you only wanted to reorder pages, or Compress PDF if the portal rejected the size.
This page will not turn the packet into a Word document, and it will not OCR a scan. If the scan has no text layer, merging it does not create one. PDF to text will tell you the file is empty of real text rather than inventing words.
Limits, formats and output
| Accepted input | |
|---|---|
| Files per batch | 2–50 |
| Soft size warning | 200 MB or 1,000 pages |
| Hard stop | 500 MB total in memory |
| Output | PDF, or a ZIP when there is more than one file |
| Account | None. The tool runs in this tab. |
Your file never leaves your device
Your PDFs are opened by a script running in this tab. The work runs in a Web Worker in this tab, using WebAssembly for the heavy parts, and the result comes back as a local blob. This site does not upload the file, store it, or log its name.
To verify: load the page, turn on airplane mode, and drop the file again. It still finishes. Or open DevTools, choose Network, and watch the run: there is no upload. The architecture is described on How it works.
Frequently asked questions
Can I merge PDF files on a phone?
Yes. The dropzone is a button first, and you can also drop or paste on a desktop. On a phone, Choose files opens the system picker. The work still runs in the tab, so a large packet needs enough free memory. If the tab runs out, you get an out-of-memory message and the files stay listed.
Will the merged file be larger?
Usually a little larger than the sum, because the new file has its own cross-reference table. It should not balloon. If the portal then complains about size, compress the result. Balanced compression recompresses ordinary JPEG images and leaves a text-only packet close to its original size.
Does merge PDF work offline?
After the page has loaded once, yes. The engines are cached by the service worker. Turn on airplane mode and run the same files again. That is also the check that nothing was uploaded the first time.
Are bookmarks preserved?
No. Outlines are dropped on purpose and the page says so before you start. Page content is preserved. If a bookmark pointed at a heading, the heading text is still on the page; only the sidebar outline is gone.
Is there a watermark on the download?
No. The file you download is the merged PDF and nothing else. The site is free because of display ads on the page, not because of a stamp inside your document.
What is the file limit?
Two to fifty PDFs. A soft warning appears around 200 MB or a very high page count, and the hard stop is 500 MB in memory. Split a huge scan into smaller jobs if the tab warns you.
Last updated 2026-09-26. By Tam.