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PDF · Local utility

PDF Merger

Merge 2-12 PDFs in your chosen order — up to 50 MiB and 500 pages combined — entirely in the browser, with per-file validation.

Task path / input to outcome

Add your PDFs

Runs locally · Nothing is uploaded

How PDF Merger works, privacy, and related tools

Task path / input to outcome

How to merge PDF files

  1. 01

    Add your PDFs

    Select Choose PDF files and pick two to twelve documents, up to 20 MiB each and 50 MiB combined. Nothing is uploaded; the files open inside this tab. Every file's name, size, and running total are listed, and a file whose content fails the PDF header check is refused before it can poison the merge. The file picker accepts a fresh selection at any time, replacing the current list entirely.

  2. 02

    Set the merge order

    The list order becomes the page order of the final document, and the first file contributes the opening pages. Move a file up or down with the arrow controls next to its name, or remove it with the × control, until the sequence reads correctly. Load sample builds a small set of synthetic PDFs locally if you want to rehearse the flow first.

  3. 03

    Merge the documents

    Press Merge PDFs. File sizes are checked before processing; PDF headers, readability, empty sources, and the 500-page combined limit are checked as the files are opened. An invalid file can stop the run. Cancel discards the pending result; download only after the merge succeeds.

  4. 04

    Download the result

    Save the merged PDF from the result panel, which reports the file count, page count, and output size of the combined document; the download is named toolars-merged.pdf. Reset clears the workspace — files, result, and status — before you load a different set of documents.

Tool facts

Processing
In your browser
Input leaves this device
Never
Retention
Nothing is stored
Price
Free

Your input stays in the browser.

PDF Merger uses its verified local execution path and does not create a hidden input or output history.

Local execution

Runs inside the current browser tab.

No hidden processing

Active tool data never becomes a Toolars document record.

No account required

Use the core workflow without creating a profile. Favorites sync to your account after you sign in.

Immediate reset

Clear the tab and the active working data is gone.

When PDF Merger is useful

Combine a document and appendix

Select A.pdf with two pages and B.pdf with one page. Keep A before B and merge. The three-page download contains A1, A2, B1; check this order before sharing.

Put the appendix first

With the same files, move B.pdf above A.pdf before merging. The download now contains B1, A1, A2. Reordering moves whole files; use the page organizer for individual pages.

Recover from a single-file selection

One PDF is not enough to merge. Select both A.pdf and B.pdf together and retry. A new file-picker selection replaces the current list; it does not append to it.

What PDF Merger actually does

Merging is the last step of many document jobs: combining a signed contract with its appendices into one sendable file, stitching twelve chapter exports into a single manuscript for the editor, or bundling a month of invoices and receipts — a 40 MiB batch — for the accounting handoff. PDF Merger assembles the pages in exactly the order you arranged, with the counts reported at the end, so a quick spot check against the source list takes seconds. And because the merge runs entirely in the browser, confidential drafts, HR paperwork, and financial records never leave the device while they are combined.

Common questions

How many PDFs can I merge at once?
Merge two to twelve PDFs, at most 20 MiB each and 50 MiB combined; the result can contain at most 500 pages. File counts and byte limits are checked before the merge. Page counts and document readability can only be checked when each PDF opens.
In which order are the files merged?
Pages follow the exact order of the file list: the first file in the list contributes the opening pages, the second file continues from there, and so on. Use the up and down controls next to each file name to rearrange the sequence before merging; nothing is re-sorted alphabetically or by date behind your back.
Why was my file refused as not a PDF?
Every file is checked twice: its name and type must claim PDF, and its first bytes must carry a real PDF header. A spreadsheet renamed to end in .pdf fails the header check, an empty file is refused on its own, and the message names the offending file so you know which one to replace.
What does the Load sample button do?
It generates a small set of synthetic PDF documents locally — no download, no upload — and loads them into the merge list, so you can rehearse reordering, merging, and downloading before trusting the flow with real paperwork. Reset swaps the samples out for your own files in one click, and the same limits apply to the sample run as to a real one.
Are my documents uploaded anywhere?
No. The merge runs fully inside the current browser tab and the files never leave your device. No account is required, and closing or resetting the workspace discards every reference to the loaded documents.

Keep reading

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