Negative keywords tell Google Ads which searches an ad should never show for. Positive keywords describe where an ad can appear. Negatives draw the boundary around that space.
As broad match and AI Max expand how many queries a single keyword can match, that boundary has become one of the most labor-intensive controls in an account. The positive side of matching is covered in What Are Keyword Match Types?. This guide focuses on the negative side.
How Negative Match Types Work
Google Ads’ negative keyword documentation defines three match types. The table below uses a payroll software campaign as an example.
| Negative keyword | Match type | Blocked search | Not blocked |
|---|---|---|---|
| free payroll | Negative broad | payroll software free trial | no cost payroll app |
| ”payroll jobs” | Negative phrase | remote payroll jobs | payroll specialist jobs |
| [payroll software] | Negative exact | payroll software | payroll software for startups |
Despite the name, negative broad match is far narrower than positive broad match. Positive broad match reaches searches with related meaning. Negative broad match only blocks a search when every word in the negative appears in it, in any order.
Negatives Don’t Cover Close Variants
Google’s documentation is explicit that negative keywords don’t match to close variants or other expansions. On the positive side, plurals, misspellings, and synonyms are picked up automatically. On the negative side, each one has to be added separately.
In English, that gap usually shows up in three places:
- Plurals and verb forms: “job” doesn’t block “jobs,” and “hire” doesn’t block “hiring.”
- Common misspellings: “payrol” and “pay roll” slip past a “payroll” negative.
- Synonyms: “free” doesn’t block “no cost,” “gratis,” or “open source.”
The navigational query trap
One category of wasted spend is easy to miss because it looks like brand interest. Searches such as “yourbrand login,” “yourbrand support,” or “yourbrand cancel subscription” come from existing customers who are trying to reach an account, not buy. In a non-brand or Performance Max campaign, those clicks cost money and rarely produce a new conversion. Adding “login,” “sign in,” “support,” and “cancel” as negatives usually removes them with little risk.
The 16-Word Limit
According to the documentation, negative keywords that appear after the 16th word of a long search may not stop an ad from showing. Short queries never reach that limit. Long, conversational queries can.
Which Level Each Negative Belongs On
| Level | Scope | Typical use |
|---|---|---|
| Ad group | That ad group only | Routing traffic between ad groups in the same campaign |
| Campaign | Every ad group in the campaign | Irrelevant intent specific to one campaign |
| Negative keyword list | Every campaign the list is attached to | Recurring intents such as jobs, free, or training |
| Account level | All eligible Search and Shopping inventory in supported campaign types | Queries the brand never wants to appear for anywhere |
Ad Group Negatives as a Routing Tool
Ad group negatives are often underused as a routing tool. If “payroll software” and “HR software” live in separate ad groups, Google decides which one serves for “HR and payroll software.” Adding “HR” as a negative in the payroll group sends that search to the HR group, where the ad copy fits better. This is especially valuable in campaigns covering related but distinct products or services within the same account.
Performance Max, Display, and Video Campaigns
Performance Max supports up to 10,000 campaign-level negative keywords. They apply to Search and Shopping inventory only and don’t block YouTube, Display, Discover, or Gmail placements. For Display and Video campaigns, the documentation notes that a maximum of 1,000 negative keywords is considered. The lower limit reflects the different matching logic in visual and video formats, where keyword relevance works differently than in search.
Building a Negative List From Search Terms
The search terms report is the main source for negatives. Sorting it by cost brings queries that spend without converting to the top. Grouping them by intent is faster than judging each query on its own.
| Intent group | Example query | How to handle it |
|---|---|---|
| Job seekers | payroll clerk jobs near me | Shared list, with singular and plural forms |
| Free seekers | free payroll calculator | Negative for paid products, reviewed first if a free trial exists |
| Research and education | what is payroll, payroll course | Negative in sales campaigns, kept in content campaigns |
| Existing customers | yourbrand login | Negative in non-brand and Performance Max campaigns |
| Competitor customers | competitor login | Negative for login and support, kept for “alternative” or “vs” queries |
Common Mistakes
The first mistake is adding a one-word broad negative without checking what it removes. “Calculator” might look irrelevant for payroll software, until it blocks “payroll tax calculator software,” which converts.
The second is having the same term as both a positive keyword and a negative. The negative always wins, and the positive never serves. This often comes from a shared list attached months earlier, which makes it hard to spot. Other reasons a keyword gets no impressions are listed in Why Isn’t My Ad Showing?.
The third is treating the list as finished. Every expansion of Google’s matching, including the AI Max transition, brings new query types into the report.
Summary
Negative keywords define where ads won’t show. Negative broad, phrase, and exact match are much narrower than their positive counterparts and ignore close variants, so plurals, misspellings, and synonyms have to be added by hand. The list is built from the search terms report by intent group and needs regular review.