How many PDFs can I merge at once?

You can merge up to 20 PDF files in a single operation. The total combined size should be under 200MB for best performance. For merging more files or larger files, split into multiple batches or use desktop software like Adobe Acrobat.

Can I reorder the PDFs before merging?

Yes! After selecting your PDFs, you can drag and drop them to reorder. The files will be merged in the order they appear in the list. This is perfect for organizing chapters, invoices, or any sequence-dependent documents.

Will merged PDFs preserve bookmarks and links?

Yes, our merge tool preserves all PDF features including bookmarks, hyperlinks, form fields, and metadata. However, if multiple PDFs have conflicting bookmarks, they may be combined or reorganized. Internal links within each PDF are preserved.

Can I merge password-protected PDFs?

No, password-protected PDFs must be unlocked first. Use our PDF Unlock tool to remove passwords from each PDF, then merge the unlocked files. This ensures all pages can be properly combined.

What happens if PDFs have different page sizes?

PDFs with different page sizes are merged as-is, preserving each page's original dimensions. The resulting PDF will contain pages of varying sizes. If you need uniform page sizes, use a PDF editor to resize pages before merging.

Does merging preserve bookmarks and links?

Yes. The PDF merger preserves internal links, bookmarks, and annotations from all source files. The table of contents and cross-references within each document continue to work in the merged output. However, cross-document links (linking from one source PDF to another) are not automatically updated.

Is there a limit to how many PDFs I can merge?

There is no hard limit on the number of files. The practical limit depends on your device's available memory. Most devices can comfortably merge 20-50 PDFs at once. For very large merges (50+ files or files totaling hundreds of megabytes), processing time increases but the tool remains functional.

Can I reorder pages before merging?

Yes. After selecting your PDF files, you can drag and drop them to arrange the desired order before merging. The files will be combined in the exact sequence you specify. This is useful when assembling reports, document packages, or multi-chapter documents.

PDF Merger - Combine Up to 20 Files Free

When to Use This Tool

Use this when:

You need to combine multiple invoices or receipts into one PDF for record-keeping
You're merging scanned document pages that were scanned separately
You want to combine book chapters or report sections into a single document
You're organizing multiple PDFs (contracts, forms, certificates) into one file
You need to merge presentation slides from different sources
You're creating a portfolio by combining multiple project PDFs
You want to consolidate multiple reports into one comprehensive document

Don't use this if:

You need to merge more than 20 PDFs at once (use desktop software or split into batches)
You require advanced page manipulation like rotating or resizing during merge
You need to merge password-protected PDFs (unlock them first)
You want to preserve complex interactive forms or annotations (use specialized PDF software)
You're merging very large PDFs (100MB+ each) that may cause browser crashes

What is a PDF Merger?

A PDF merger combines multiple PDF files into a single document, preserving the content, formatting, and bookmarks of each source file. Our online PDF merger works entirely in your browser — your files are never uploaded to any server.

Merging PDFs is a common need in professional and academic settings: combining separate chapters into a single report, assembling scanned pages into one document, or consolidating invoices for accounting. Instead of printing and rescanning, a digital merger handles it instantly.

This tool benefits office administrators preparing document packages, students compiling research papers, real estate agents assembling closing documents, and legal professionals combining contracts with appendices. You can reorder pages by dragging and dropping before merging.

Compared to Adobe Acrobat (which costs $20+/month) or online tools like SmallPDF and ILovePDF (which upload your files to their servers), PureXio's merger keeps all processing local. No upload limits, no watermarks on output, and no privacy concerns with sensitive documents. The tool uses pdf-lib, a proven JavaScript library, to perform lossless merging directly in your browser.

Simply select your files, arrange them in the desired order, and download the merged result in seconds.

Best for: combining 2–50+ PDF files into one document. No upload limits, no watermarks, no server processing. Fully private and free.

How to Merge PDFs

Select multiple PDF files (up to 20) by dragging and dropping or clicking to browse

Drag files to reorder them in the desired sequence before merging

Click 'Merge PDFs' and download your combined PDF file

Common Use Cases

Combine 12 monthly invoices (each 2-3 pages) into one annual invoice PDF for accounting

Merge 5 scanned document pages that were scanned separately into a single document

Combine 8 book chapters (each 10-15 pages) into one complete book PDF

Merge 3 contract PDFs and 2 addendums into one comprehensive contract document

Combine 15 presentation slides from different sources into one presentation PDF

Merge 6 project proposal PDFs into one portfolio document for client submission

Combine 3-5 certificates or diplomas (2-3 pages each) into one credential portfolio PDF

Features

Merge up to 20 PDF files in a single operation

Drag and drop reordering to control page sequence

Preserves all PDF features: bookmarks, links, form fields, and metadata

Maintains original quality of all merged documents

100% private—all processing happens in your browser

No file size limits (limited by browser memory, typically 200MB total)

Works offline after initial page load

Limitations & Constraints

Maximum 20 PDFs per merge operation. For more files, split into batches or use desktop software.

Total combined file size should be under 200MB. Very large merges may cause browser slowdowns or crashes.

Password-protected PDFs must be unlocked first before merging (use PDF Unlock tool first—this ensures all pages can be properly combined).

Complex interactive forms may lose some functionality when merged. Test merged PDFs with form fields.

Page numbering is not automatically adjusted. If you need sequential page numbers, use PDF editing software.

Troubleshooting

Merge fails with 'File too large' or browser crashes

Solution: Reduce the number of files or their sizes. Try merging in smaller batches (5-10 files at a time). Close other browser tabs to free up memory. If total size exceeds 200MB, use desktop software. Prevention: Keep total combined size under 150MB for reliable merging.

Merged PDF has pages in wrong order

Solution: Use the drag-and-drop feature to reorder files before clicking 'Merge PDFs'. Files are merged in the order they appear in the list. Double-check the order before merging. Prevention: Review file order carefully before merging, especially when merging many files.

Some PDFs won't merge (error message appears)

Solution: Check if any PDFs are corrupted—try opening them individually in a PDF reader. Password-protected PDFs must be unlocked first. Very old PDFs (pre-2000) may have compatibility issues. Try converting problematic PDFs to a newer format first. Prevention: Ensure all PDFs open correctly before attempting to merge.

Merged PDF is missing bookmarks or links

Solution: Complex bookmarks from multiple PDFs may be reorganized during merge. Internal links within each PDF are preserved, but cross-PDF links may break. For critical bookmark preservation, use desktop software like Adobe Acrobat. Prevention: Test merged PDFs to verify all important features are preserved.

Merge process is very slow or seems stuck

Solution: Large files or many files can take 30-60 seconds to merge. Check your browser's task manager to see if it's still processing. If it's been more than 2 minutes, refresh and try with fewer or smaller files. Ensure stable internet connection for initial page load. Prevention: Keep individual files under 20MB and total combined size under 150MB for faster merging.