Merge PDF Files
Combine multiple PDF documents into one file online — free, fast, and with full control over page order.
- ✓ Free
- ✓ No watermarks
- ✓ Any number of files
- ✓ Secure
or drag and drop multiple PDFs here
By using this tool you agree to our terms of use
Drag thumbnails to reorder · click to select
Why use PDF99?
Combine any number of files
Add as many PDFs as you need — no limit on documents or total page count.
Control the order
Files are merged in the order shown. Add them in sequence from the start.
Runs in your browser
PDF-lib merges documents locally. Your files aren't uploaded to a remote server.
Preserves original quality
Pages are copied exactly — no re-rendering, no quality loss.
Handles different page sizes
Mixed page dimensions and orientations are preserved exactly.
Free, no watermarks
No limits, no branding added to your output.
What does merging PDFs mean?
Merging combines multiple separate PDF files into a single document. Each source PDF contributes its pages to the output in the order you specify. The pages are not re-rendered or altered — they are copied exactly. This is used to combine separate scanned pages into one document, combine report sections from different authors, or consolidate multiple invoices into one submission.
How to merge PDF files
Upload your PDFs
Add two or more PDF files using the picker or drag and drop.
Check the order
Files merge in the order shown in the thumbnail area.
Merge and download
Click Merge PDFs and download your combined document.
Frequently asked questions
No limit.
Never.
Not directly — use Unlock PDF (coming soon) first.
Yes. Merging runs in your browser using PDF-lib.
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