Level: Basic
Most real keyword research draws on more than one source, and combining those lists cleanly in Excel is a foundational early step.
The Excel Technique
Paste each source into its own column or sheet, then stack them into a single column using a simple formula reference or by copying values down sequentially. Once combined, run Data > Remove Duplicates on the full stacked list to eliminate overlap between the sources.
Example Scenario
You've pulled keyword ideas from your own site search data, a competitor's content, and a research tool export — three separate lists that need to become one clean, deduplicated master list before any prioritization work begins.
Where This Fits in Your Keyword Research Process
Combining before deduplicating, rather than deduplicating each source separately, is important — a term unique within each individual list might still be a duplicate once all three are merged together.
Next step: Use Merge Two Lists (Union) from SeoWolf's Notepad to combine your three source lists into one clean, already-deduplicated list before you ever paste anything into Excel, skipping the manual stack-and-dedupe process entirely.