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How to Merge PDF Files Online — Complete Guide

Combine multiple PDFs in order without blurring logos. iText smart merge, reorder tips, and post-merge compression.

Published June 1, 2025 · 1 min read

Written by Ethan Brooks · Editor-in-Chief & Product Lead

Reviewed by James Cole

Last reviewed January 15, 2026 · Editorial policy

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When merging PDFs saves time

Accountants attach invoices to payment proofs. Recruiters bundle CV, cover letter, and certificates. Landlords combine lease, inventory, and ID copies. Merging avoids sending three separate emails and keeps page order under your control.

How RatPDF merge preserves quality

Unlike tools that rasterize every page to JPEG, RatPDF appends pages with iText smart mode — vector text, fonts, and logos stay sharp. Bookmarks from source files are preserved when the PDF structure allows it.

Step-by-step

Go to Merge PDF.
Upload two or more PDFs (drag to reorder if the UI supports it).
Submit and download the combined document.

Tips for clean results

Merge in logical order: cover letter → resume → portfolio.
If one file is landscape and another portrait, rotate pages first with our rotate guide.
After merging a large pack, compress for email.

Sources & references

Primary references used when researching and fact-checking this guide. See our editorial methodology.

Adobe PDF Reference — encryption — Adobe
PDF password protection and encryption standards (ISO 32000).