Negative keywords are words or phrases that prevent your Google Ads from appearing when those terms are included in a search query. Adding 'free' as a negative keyword, for example, prevents your ads from appearing when someone searches 'free digital marketing software' — eliminating an irrelevant click that would never convert. Negative keywords are one of the most impactful optimisation levers in Google Ads — they reduce wasted spend on non-converting traffic, improve average Quality Score by making your ads more relevant to remaining impressions, and lower cost-per-acquisition.
Negative keywords are systematically underutilised by most Google Ads accounts. New campaigns launched without negative keywords will typically spend 20-40% of their initial budget on irrelevant searches before the algorithm self-optimises. Proactive negative keyword management — before launch and continuously throughout the campaign — significantly improves campaign efficiency from day one.
How to find and add negative keywords
- Search Term Report — the primary source; review every week, add irrelevant queries as negatives
- Keyword brainstorming — think about what adjacent searches your keywords might trigger; add obvious irrelevant terms before launch
- Negative keyword lists — create shared lists (e.g. 'irrelevant intent terms', 'competitor names') applied across multiple campaigns
- Campaign-level vs ad group level — broad exclusions at campaign level; more targeted exclusions at ad group level
- Match types matter — negative broad match excludes any query containing the term; negative exact match only excludes exact queries
- Common negatives: 'free', 'cheap', 'jobs', 'salary', 'how to', 'DIY' depending on campaign objectives
For active campaigns, review the Search Term Report at least weekly — more frequently in the first month of a new campaign. Newly launched campaigns especially need aggressive negative keyword management as the algorithm is still learning targeting patterns. Set a weekly calendar reminder to review new search terms, add irrelevant terms as negatives, and note any surprisingly relevant terms that indicate new keyword opportunities. Accumulated unmanaged search terms in a new account can waste thousands of pounds in the first few months.
Yes — over-aggressive negative keyword lists can exclude legitimate potential customers. Adding 'review' as a negative keyword might seem sensible (excluding searchers looking for reviews) but will also exclude 'our service review' or research-phase queries that sometimes convert. Test the impact of significant negative additions — if impressions drop dramatically without a proportional improvement in CTR and conversion rate, some negatives may be too broad. Negative keyword management requires judgment, not just adding anything that sounds off-topic.