How many PDF files can I merge at once?

There is no limit on the number of files, only on their combined size: all the PDFs you add can total up to 100 MB. For most use cases that is dozens of files.

Can I reorder the files before merging?

Yes. Use the up (↑) and down (↓) arrow buttons on each file row to set the order, or remove any file you decide not to include.

Will the formatting and images inside each PDF be preserved?

Yes. Pages are copied from the source PDFs exactly as they are, text, images, fonts, and layout are all preserved.

Do I need to create an account?

This tool is completely free and requires no account, login, or personal information.

How do I check the total before merging?

The line under the file list keeps a running count, for example '3 files · 42 pages total', and each file row shows its own page count. Use × on a row to drop a file you added by mistake.

Merge Multiple PDF Files

Add as many PDF files as you need, use the arrows to put them in order, then download the merged PDF. All processing runs in your browser.

Drop PDF files here or click to browse

You can add multiple files

How it works

Each PDF you add is parsed by pdf-lib in your browser. The tool walks the list in the order you arranged the files and copies every page from each source document into a new target document. Because pages are copied rather than re-rendered, fonts, images, and links from every source PDF survive intact in the merged file. Form fields keep their values, but the merged file has no document-level form, so viewers may no longer let you fill them in; fill forms before merging.

Processing runs in your browser

All merging happens inside your browser tab. pdf-lib combines your PDFs entirely in memory; our servers are not involved at any point. You can confirm this yourself in your browser's DevTools Network tab.

Related operations

For pulling out a single section before merging, try split PDF. To straighten sideways scans first, use rotate PDF. For shrinking the combined file, see compress PDF.

Frequently asked questions

How many PDF files can I merge at once?: There is no limit on the number of files, only on their combined size: all the PDFs you add can total up to 100 MB. For most use cases that is dozens of files.
Can I reorder the files before merging?: Yes. Use the up (↑) and down (↓) arrow buttons on each file row to set the order, or remove any file you decide not to include.
Will the formatting and images inside each PDF be preserved?: Yes. Pages are copied from the source PDFs exactly as they are, text, images, fonts, and layout are all preserved.
Do I need to create an account?: This tool is completely free and requires no account, login, or personal information.
How do I check the total before merging?: The line under the file list keeps a running count, for example '3 files · 42 pages total', and each file row shows its own page count. Use × on a row to drop a file you added by mistake.

Last reviewed September 30, 2026

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