What are negative keywords in Google Ads?
By NegativeShield · Updated
Negative keywords are terms you add to a Google Ads campaign or ad group to prevent your ads from showing when a search contains them. They are the inverse of regular keywords: instead of triggering an ad, they suppress it. Used well, they cut wasted spend by filtering out irrelevant traffic — people searching for something you don't sell, free alternatives, jobs, or competitors — so your budget goes to searches that can actually convert.
How negative keywords work
When someone searches on Google, the system matches their query against your keywords to decide whether to show your ad. Negative keywords add a second check: if the query contains one of your negatives, the ad is suppressed even if a regular keyword matched.
You can add negatives at three levels: the ad group (narrowest), the campaign, or a shared negative keyword list applied across many campaigns. Shared lists are the most efficient way for agencies to maintain a common exclusion set across client accounts.
Negative keyword match types
Negative keywords use the same broad, phrase and exact match types as regular keywords, but the logic is stricter — negatives never match close variants, misspellings, synonyms or plurals. You must add those variations explicitly.
Negative broad match blocks a search only when it contains all of your negative's terms, in any order. Negative phrase match blocks searches that contain your terms in the same order. Negative exact match blocks only searches that are exactly your term, with no extra words.
How to find negative keywords
The richest source is the Search Terms report, which shows the actual queries that triggered your ads — as opposed to the keywords you bid on. Reviewing this report reveals irrelevant queries you are paying for.
At scale this review is slow and error-prone, which is where automated classification helps: an LLM can read each search term in the context of what a business actually sells and flag the irrelevant ones, with a reason you can verify before anything is excluded.
Frequently asked questions
Do negative keywords lower my costs?
Indirectly, yes. They don't change your bids, but by preventing clicks on irrelevant searches they stop you paying for traffic that won't convert, which lowers wasted spend and can improve overall ROAS.
Can negative keywords hurt my campaigns?
They can if they're too broad. An overly aggressive negative can block valuable searches. That's why each exclusion should be reviewed in context before it's applied.
How many negative keywords should I have?
There's no fixed number — it depends on how much irrelevant traffic your search terms reveal. The goal is coverage of genuinely irrelevant queries, not a quota.