If you’ve ever run Google Ads and wondered where your budget went, negative keywords are probably a large part of the answer. They’re the most under-used feature in paid search advertising, and getting them wrong — or ignoring them entirely — is one of the most reliable ways to waste money on ads.
The concept is simple. A negative keyword is a word or phrase that tells Google: don’t show my ad for searches containing this. You’re not telling Google who to target — you’re telling Google who to exclude. Done properly, negative keywords mean your budget only gets spent on searches that are actually relevant to your business.
Why Negative Keywords Matter So Much
Google Ads works on an auction system. You bid to appear for certain search terms, and Google shows your ad to people who search for those terms — or terms Google thinks are related. That last part is the problem.
Google’s broad and phrase match types (and especially the default settings in many campaigns) will show your ad for searches that are tangentially related to your keywords at best, and completely irrelevant at worst. A plumber bidding on “plumber London” might show up for “how to become a plumber London”, “plumber salary London”, or “plumber apprenticeship London”. None of those people want to hire a plumber right now. But Google charged for those clicks anyway.
Negative keywords are what stop that happening.
The Three Match Types (They Apply to Negatives Too)
Just like positive keywords, negative keywords have match types:
Broad match negative — the default. Blocks your ad from showing when all the words in your negative keyword appear in the search, in any order. Adding “how to” as a broad match negative would block “how to find a plumber” and “find a plumber how to”, but not “find a plumber” alone.
Phrase match negative — blocks searches containing that exact phrase in that order. Adding “how to” as a phrase match negative (written as “how to” with quotes) blocks any search containing those two words in sequence.
Exact match negative — only blocks searches that match the exact term, nothing else. Adding [plumber salary] as exact match negative blocks only the search “plumber salary”, not “plumber salary guide” or “what is a plumber salary”.
For most campaigns, phrase match negatives give the right balance — specific enough to be useful, broad enough to catch variations.
Building Your Initial Negative Keyword List
Before your campaign goes live, add an initial list of obvious negatives. You don’t need to wait for data — there are predictable categories of irrelevant searches for almost every business:
Job and career terms
Unless you’re recruiting, add: jobs, job, career, careers, salary, salaries, apprenticeship, apprenticeships, vacancy, vacancies, how to become, training course, qualification.
Free and DIY terms
If you sell a paid product or service: free, cheap, cheapest, DIY, do it yourself, how to, tutorial, guide, template, download.
Unrelated products or services with similar names
If your business name or keywords have double meanings, these are crucial. A recruitment agency called “Summit” needs to exclude “mountain summit”, “summit climbing” etc. A software company with “pipe” in the name might need to exclude plumbing-related terms.
Competitor research intent
Searches like “review”, “reviews”, “complaints”, “vs”, “alternative to” can sometimes be valuable (people comparing options) but often aren’t. Test before excluding — for some businesses these searches convert well.
Informational queries your service doesn’t answer
What questions are people asking that you can’t help with? “What is X”, “history of X”, “X statistics” often signal research intent rather than buying intent.
The Search Terms Report: Your Ongoing Source of Truth
Your initial list won’t catch everything. The most valuable thing you can do in the first weeks of a campaign is check the Search Terms report regularly. This shows you the actual searches that triggered your ads — not the keywords you’re bidding on, but the real queries Google decided were relevant enough to show your ad for.
In Google Ads: go to Keywords → Search Terms. Sort by spend. Look for searches that are clearly irrelevant or converting poorly. Add them as negatives. Do this weekly for the first month, then monthly once the campaign is stable.
This is where you’ll find the odd, specific queries that no initial list would predict — the brand name you share with a band, the product that sounds like yours but isn’t, the regional slang that has a completely different meaning somewhere else.
Negative Keyword Lists: Work Smarter Across Campaigns
If you run multiple campaigns, Google Ads lets you create shared negative keyword lists that apply across all of them at once. Create a master list of negatives that apply to your whole account (jobs, free, DIY, etc.) and attach it to every campaign. When you find a new irrelevant term, add it to the shared list once and it blocks across everything.
This saves significant time and prevents the same irrelevant searches from burning budget in multiple campaigns simultaneously.
Common Mistakes
Being too aggressive with negatives. Adding too many can shrink your audience to the point where your ads barely show. If you exclude “reviews”, you might also block people searching “[your business name] reviews” — people who already know you and are one step from converting. Check the search terms report before excluding anything that might have legitimate buying intent.
Never updating them. Negative keyword management isn’t a one-time setup. Search behaviour changes, new irrelevant terms emerge, your campaign evolves. Put a monthly calendar reminder to review the Search Terms report.
Ignoring them in Performance Max campaigns. Google’s Performance Max campaigns run across all ad formats and placements. Negative keywords apply differently here — you need to add them as account-level negatives or request campaign-level negatives via Google support. PMax campaigns without proper negatives can waste significant budget on entirely irrelevant placements.
Frequently Asked Questions
How many negative keywords should I have?
There’s no magic number. A new campaign might start with 20–50 obvious negatives and grow to several hundred over time as you review actual search data. More important than volume is relevance — a targeted list of 50 well-chosen negatives will outperform a bloated list of 500 that accidentally excludes good searches.
Do negative keywords affect my Quality Score?
Indirectly, yes — in a positive way. By filtering out irrelevant searches, negative keywords improve your click-through rate (because the people who do see your ad are more likely to click) and improve your conversion rate (because the clicks you get are more relevant). Both factors contribute to a better Quality Score over time, which lowers your cost per click.
Can I use negative keywords in Shopping campaigns?
Yes. Shopping campaigns don’t use traditional keyword targeting, but they do support negative keywords to exclude searches you don’t want to show for. The same principles apply — start with obvious irrelevant terms and refine based on search terms data.
What’s the difference between negative keywords and audience exclusions?
Negative keywords control which search queries trigger your ads. Audience exclusions control which people see your ads regardless of what they searched. Both are useful — negative keywords handle irrelevant queries, audience exclusions handle irrelevant people (e.g. excluding existing customers from acquisition campaigns, or excluding demographics that never convert for your business).
Should I exclude competitor brand names?
Not necessarily. Searches for competitor names can be valuable — people comparing options are often further along in the buying process than generic searchers. Whether to bid on competitor terms (and exclude them from certain campaigns) depends on your competitive position, margins, and whether your offer is differentiated enough to win comparisons. Test before deciding either way.
