Are the PDFs uploaded?

No. Parsing, previews, and merging run in the current browser tab.

What happens to an invalid or locked file?

Corrupt and non-PDF files are rejected during preflight. A password-protected PDF stays in a separate queue where you can enter its known password and add the locally decrypted copy to the merge list.

Are PDF passwords uploaded or stored?

No. Password verification and decryption happen in the current browser tab. The password field is removed from the workspace as soon as that file is unlocked and added.

Does merging reduce page quality?

Pages are copied without screenshot rasterization or intentional image recompression, so their dimensions and visible content remain intact.

Is there a page limit?

There is no fixed server limit. Available device memory, browser limits, file complexity, and preview rendering determine the practical maximum.

Can mixed page sizes be merged?

Yes. Portrait, landscape, A4, Letter, and other source dimensions can coexist, and each copied page keeps its own size.

PDF Tools

Merge PDF

Validate, unlock, preview, reorder and combine multiple PDF files into one polished document.

Free browser toolRuns in your browserNo sign-up

PDF assembly studio

Build one polished document

Validate PDFs before merging, inspect every page, drag documents into order and keep the original vector quality.

files loaded

total pages

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source size

Drop PDF files here or browseCorrupt and non-PDF files are rejected. Password-protected PDFs can be unlocked below.

Private workspace. Files stay in this browser tab and are never uploaded to ToolsOnDuty.

Add at least two valid PDFs to continue.

About the Merge PDF

Merge PDF combines complete PDF documents in a chosen order. Each file is parsed before it enters the workspace, so corrupt and non-PDF files are rejected while password-protected documents move into a private inline unlock queue without blocking valid selections.

First-page thumbnails support a quick check, while expandable previews show every page progressively. File sizes, individual page counts, and the combined page count help confirm that the intended reports, scans, or appendices are present before work begins.

The merger copies source pages into a new PDF instead of rendering screenshots. Page dimensions and visible quality are retained, but document-level features such as outlines, attachments, digital signatures, and interactive form behavior may not survive the copy.

Validation, password checking, decryption, previews, sorting, and merging run in the browser. Passwords are never uploaded or stored. There is no fixed service quota, although many large or image-heavy PDFs can exceed the memory available to a phone, tablet, or browser tab.

Key features

Upload-time checks that separate locked PDFs from corrupt or non-PDF files
Inline password entry and local unlocking for documents you are authorized to use
Per-file page counts and sizes plus a combined page total
Expandable all-page previews with progressive rendering and zoom
Drag ordering, accessible move controls, sorting, and upload-order reset
Merge progress followed by output page count, size, and processing time
Custom output filename with an explicit download step
Copied source pages rather than rasterized screenshots
Private browser processing with no watermark or sign-up

How to use

1Drop at least two PDFs into the workspace or browse for files.
2Review any skipped-file notice. If a locked PDF appears, enter its password, confirm you have permission, and select Unlock & add.
3Verify the accepted file names, sizes, and page counts.
4Expand Preview when page-by-page inspection is needed, and adjust thumbnail zoom if useful.
5Drag files into order, use the move buttons, sort them, or reset to the original upload order.
6Select Create merged PDF and wait for the local progress to finish.
7Review the result summary, choose a filename, and select Download PDF.

Examples

Assemble a submission pack

Input: 2-page cover, 18-page report, and 4-page appendix

Output: One 24-page PDF in the reviewed order

Expand the appendix preview and verify the final page count before downloading.

Frequently asked questions

Are the PDFs uploaded?: No. Parsing, previews, and merging run in the current browser tab.
What happens to an invalid or locked file?: Corrupt and non-PDF files are rejected during preflight. A password-protected PDF stays in a separate queue where you can enter its known password and add the locally decrypted copy to the merge list.
Are PDF passwords uploaded or stored?: No. Password verification and decryption happen in the current browser tab. The password field is removed from the workspace as soon as that file is unlocked and added.
Does merging reduce page quality?: Pages are copied without screenshot rasterization or intentional image recompression, so their dimensions and visible content remain intact.
Are forms, bookmarks, and signatures preserved?: Visible page content is copied, but document-level outlines, attachments, digital signatures, and interactive form behavior may not carry into the new PDF.
Is there a page limit?: There is no fixed server limit. Available device memory, browser limits, file complexity, and preview rendering determine the practical maximum.
Can mixed page sizes be merged?: Yes. Portrait, landscape, A4, Letter, and other source dimensions can coexist, and each copied page keeps its own size.

PDF GuidesHow to Merge PDF Files Without Losing Page OrderRead guide

Open a related tool to prepare your files or refine the finished result.