Short answer: Negative keywords tell Google which searches you do not want your ad to appear for. The quickest way to find them is the Search terms report, which shows the exact words people typed before clicking. Regular clean-ups, at least once a week when a campaign is new, are one of the most profitable jobs in the whole Google Ads account.
When a business tells us it “tried Google Ads and it didn’t work”, the reason in most of the accounts we review is the same: the money went on searches that have nothing to do with the offer. An air conditioning seller pays for clicks on “how to clean my AC myself”, a laptop repair shop pays for “cheapest used laptop”, and an agency pays for “SEO job vacancy”. Each of those clicks is small, but together they easily eat a third of the budget.
How Google actually decides when to show your ad
Keywords in Google Ads are not strict rules but a signal. Broad match shows the ad for anything Google considers related, phrase match requires the search to include the meaning of the phrase, and exact match requires the same meaning. In recent years Google has widened all three considerably, so even “exact” match now covers synonyms and close variants. That is why negative keywords are the only reliable way to rule something out.
Where to find them
The Search terms report
In your account, open Insights and reports, then Search terms. These are the exact searches that triggered impressions and clicks. Sort by cost and work down the list: for each term, ask whether the person who typed it could realistically become your customer. If not, add it as a negative keyword.
Before the campaign goes live
Some words you know in advance. For most businesses selling a service or product, the starter list includes:
- Jobs and recruitment: job, jobs, vacancy, salary, internship, careers.
- DIY and learning: how to, yourself, free, course, tutorial, pdf, training (unless that is what you sell).
- Second-hand and cheapest: used, second hand, cheapest, if that is not your offer.
- Locations you do not cover: towns or countries you do not work in, if location targeting alone is not enough.
- Competitors by name, if you do not want to appear for their branded searches.
The list has to fit the business. A language school must not exclude “course”, and a publisher of handbooks must not exclude “pdf”.
Match types for negative keywords
This is where most mistakes happen, because negative keywords work differently from positive ones: they do not include synonyms or close variants.
| Type | Example | What it blocks |
|---|---|---|
| Broad | used laptop | Any search containing both words, in any order |
| Phrase | „used laptop“ | Searches containing that phrase in that order |
| Exact | [used laptop] | Only that exact search, with no extra words |
Because there are no close variants, you need to add plurals and other forms yourself: “laptop” and “laptops”, “job” and “jobs”. The same applies to common misspellings and, in languages with accented letters, to versions typed with and without the accents, since Google does not treat them as the same word for negatives.
Negative keyword lists and levels
You can add negative keywords at ad group level, at campaign level, or as a shared list attached to several campaigns. A practical rule:
- A shared list for things you never want (jobs, free, DIY). Build it once, apply it everywhere.
- Campaign level for terms that do not fit that particular offer.
- Ad group level for steering traffic: if you have one group for “AC servicing” and another for “AC installation”, exclude “installation” from the first and “servicing” from the second, so each search reaches the right ad and the right page.
Since 2025 Performance Max campaigns also support campaign-level negative keywords, and there are account-level negatives too. Before that, it was one of the main reasons business owners lost control of their PMax campaigns.
How often to clean up
- The first four weeks of a new campaign: twice a week. That is when most surprises turn up.
- A stable campaign: once a week or every two weeks.
- After every major change (new keywords, a switch to broad match, a new offer).
The most common mistakes
- Overdoing it. If you exclude the word “price”, you lose people who are ready to buy and are just comparing offers. A negative keyword should exclude an intent, not a useful word.
- A one-word broad negative. “Free” as a negative is fine, but “website” as a negative for a web agency would switch off half the campaign.
- Conflicts with your own keywords. Google shows a warning in the account when a negative keyword blocks one of your active keywords. Check those warnings.
- Looking only at clicks. A term can have plenty of clicks and not a single enquiry. Sort by cost and conversions, not by clicks.
Frequently asked questions
Do negative keywords reduce the number of enquiries?
Well-chosen ones do not; they free up budget for searches that bring in business. If enquiries drop after you add negatives, you have probably excluded a useful word and should put it back.
How many negative keywords is too many?
There is no right number. Accounts using broad match have hundreds of negatives, and that is normal. What matters is that each one has a reason.
Does this apply to Shopping campaigns too?
Yes. Shopping campaigns have no keywords, so negatives are the only way to influence which searches your products appear for.
Conclusion
Negative keywords are not a one-off setting but a habit. A campaign that is cleaned up regularly spends less and less each month on the wrong people and more and more on the ones who buy. If you would like us to look at your account and your search terms report, see our Google Ads management service or get in touch.
Related: Google Ads Quality Score explained · Performance Max campaigns
