Merge PDF

Merge multiple PDFs into a single document. Drag files into order, rotate any of them, and download one PDF. Pages are copied exactly, so text stays selectable.

PDF ToolsProcessed locallyNo account needed

Drop the PDFs you want to combine

Pages are copied exactly, so text stays selectable and quality is unchanged.

PDFUp to 100MB100% Private

How to use Merge PDF

Simple steps to get your task done in seconds

Add PDFs

Drop two or more PDF files. Each shows its page count.

Set the order

Drag files up or down and rotate any that are sideways.

Merge and download

Get one PDF with every page, built on your device.

How Client-Side PDF Merging Works

ZapPebble combines multiple PDF documents into a single consolidated file using the native pdf-lib WebAssembly engine. Instead of converting pages into lossy bitmap images, ZapPebble clones the underlying PDF object tree—including vector line art, embedded font subsets, and high-resolution graphics—directly between documents. This guarantees zero degradation in visual fidelity and preserves pristine print quality.

Feature	Supported Capability	Technical Verification
File Count & Size	Multiple files up to 100 MB each	Limited only by available device memory (RAM).
Vector Quality Preservation	100% Lossless Page Cloning	Text layers remain fully selectable, searchable, and copyable.
Document Ordering	Drag-and-Drop & Arrow Controls	Reorder files before merge to set exact page sequences.
Document Rotation	90°, 180°, 270° Clockwise	Rotate all pages in a document without re-encoding.

Practical Example: Compiling an Onboarding Employment Packet

Source PDF Documents

Offer_Letter.pdf (2 pages)
NDA_Agreement.pdf (4 pages)
Direct_Deposit.pdf (1 page, scanned sideways)

Goal: Consolidate into a single 7-page PDF in the correct order with upright orientation.

Merge Process & Verified Outcome

Files are dragged into the dropzone in order: Offer Letter first, NDA second, Direct Deposit third.
The rotate button is clicked on Direct_Deposit.pdf to turn it upright.
Clicking "Merge PDFs" clones all 7 pages into merged.pdf in under 1 second.

Important Limitations & Troubleshooting

Password-Protected Files

If any PDF in the batch is encrypted, pdf-lib cannot copy its objects without authorization. Unlock the protected document first using ZapPebble's Unlock PDF tool.

Interactive Form Fields (AcroForms)

When merging documents with fillable form fields that share identical field names, fields are flattened to preserve the entered text and prevent field value conflicts.

Local Memory Privacy

All buffer manipulation occurs in client RAM. Your legal agreements, financial records, and private documents are never transmitted across the network.

Split PDFNeed to extract specific pages from a combined PDF? Split pages into separate documents.

Add Page NumbersAdd unified page numbers across your newly merged document.

Protect PDFAdd AES-256 password protection to safeguard your merged document.