Do my PDFs leave my device when I merge them?

No. Merge runs entirely in your browser inside a Web Worker. Files are not uploaded to any server — they stay on your device throughout the process.

How many PDFs can I combine at once?

There is no fixed limit on the number of files. Each individual file can be up to 50 MB. You can merge dozens of PDFs as long as your device has enough memory.

Can I merge password-protected PDFs?

Password-protected PDFs must be unlocked first. Use the Unlock PDF tool to remove the password, then merge the unlocked files.

Can I reorder the PDFs before merging?

Yes. After adding files, drag rows in the file list to rearrange them in any order. The merged PDF follows the sequence shown in the list.

Will bookmarks and table of contents be preserved?

The merged PDF preserves the page content and embedded fonts from each source file. Top-level bookmarks are concatenated in order.

Does Merge PDF work on mobile?

Yes. The tool runs in any modern mobile browser and supports touch-based file selection and reordering.

Yes, completely free with no watermarks, no sign-up, and no file count limits.

What happens to the metadata of merged files?

The output PDF inherits metadata from the first file in the list. You can edit metadata afterward using the Edit Metadata tool.

Merge PDF online free

About Merge PDF

Merge PDF combines multiple PDF documents into a single file — drag your PDFs into the list, reorder them freely, and download one consolidated document. Everything runs in your browser, so your files never touch a server.

Whether you are assembling a report from separate chapters, combining scanned receipts into one archive, or merging contract pages from different sources, Merge PDF handles it instantly with a drag-and-drop interface. Reorder files by dragging rows, then process to get a single output.

The tool uses pdf-lib inside a Web Worker to concatenate page trees according to the Adobe PDF specification. This ensures bookmarks, metadata, and embedded fonts are preserved across the merged output.

Because all processing is local, Merge PDF is safe for confidential documents — legal contracts, financial reports, medical records, or any file where uploading to a third-party server is not an option.

Last updated: 2026-06-29

How to use Merge PDF

1. Open Merge PDF Navigate to the Merge PDF tool in your browser.
2. Add your PDFs Drag multiple PDF files onto the drop zone, or click to browse and select them. You can add files one at a time or in bulk.
3. Reorder files Drag rows in the file list to arrange the PDFs in your desired output order. The top file becomes the first pages of the merged document.
4. Review the file list Confirm the order and check file sizes. Remove any file by clicking the delete button next to it.
5. Click Process Press the Process button. The tool merges all PDFs into a single file inside your browser — no upload occurs.
6. Download the merged PDF Once processing completes, click Download to save the combined PDF to your device.

Frequently asked questions

Do my PDFs leave my device when I merge them?: No. Merge runs entirely in your browser inside a Web Worker. Files are not uploaded to any server — they stay on your device throughout the process.
How many PDFs can I combine at once?: There is no fixed limit on the number of files. Each individual file can be up to 50 MB. You can merge dozens of PDFs as long as your device has enough memory.
Can I merge password-protected PDFs?: Password-protected PDFs must be unlocked first. Use the Unlock PDF tool to remove the password, then merge the unlocked files.
Can I reorder the PDFs before merging?: Yes. After adding files, drag rows in the file list to rearrange them in any order. The merged PDF follows the sequence shown in the list.
Will bookmarks and table of contents be preserved?: The merged PDF preserves the page content and embedded fonts from each source file. Top-level bookmarks are concatenated in order.
Does Merge PDF work on mobile?: Yes. The tool runs in any modern mobile browser and supports touch-based file selection and reordering.
Is Merge PDF free?: Yes, completely free with no watermarks, no sign-up, and no file count limits.
What happens to the metadata of merged files?: The output PDF inherits metadata from the first file in the list. You can edit metadata afterward using the Edit Metadata tool.