Quick Answer: Negative keywords are words and phrases you add to a Google Ads campaign to prevent your ads from showing on irrelevant searches. Adding them correctly reduces wasted spend, improves CTR, and pushes your budget toward searches that actually convert. There are three match types — broad, phrase, and exact — and knowing which one to use is what separates a well-run account from one leaking money.
What Are Negative Keywords?
Every time someone types a query into Google, your ads compete in a real-time auction. Negative keywords are your veto power. They tell Google: “No matter how relevant you think this query is, do not show my ad for it.”
Why they matter beyond budget protection:
- Quality Score: Irrelevant traffic pulls your Quality Score down, increasing your CPC across the board. Negative keywords keep your match quality high.
- CTR: Ads shown to the wrong audience get ignored, suppressing your click-through rate.
- Conversion rate: Every wasted click raises your cost per acquisition (CPA).
Why Negative Keywords Are Critical
An independent analysis of over $20 million in Google Ads spend found that hidden search terms can cost advertisers up to 85 cents of value per ad dollar. Seer Interactive’s research found that advertisers see data for only about $71,000 of every $100,000 they spend — roughly $29,000 in spend that flows through queries you can’t even analyze, let alone negate.
With Google pushing broad match and smart bidding harder than ever, negative keywords have become your primary lever for maintaining control. Match types are blurrier than they used to be — the only reliable way to lock out irrelevant traffic is to explicitly exclude it.
Negative Keyword Match Types
Negative keywords use the same three match type labels as positive keywords — but they work very differently. The most important difference: negative keywords do NOT expand to synonyms or close variants. You have to add variations manually.
Negative Broad Match
Negative broad match is the default when you add a keyword without any syntax. Your ad won’t show if the search query contains all of your negative keyword terms, in any order.
| Search query | Ad shows? |
|---|---|
| running shoes | ❌ No |
| blue running shoes | ❌ No |
| blue tennis shoes | ✅ Yes |
| running gear | ✅ Yes |
Negative Phrase Match
Add quotation marks: "running shoes". Your ad won’t show if the search query contains your keyword phrase as an intact sequence. This is the workhorse of negative keyword strategy.
| Search query | Ad shows? |
|---|---|
| running shoes | ❌ No |
| blue running shoes for women | ❌ No |
| running shoe (singular) | ✅ Yes |
| trail running footwear | ✅ Yes |
Negative Exact Match
Wrap in square brackets: [running shoes]. Your ad won’t show only when the search query matches exactly. Any variation can still trigger your ad. Best for surgical exclusions of specific queries.
How to Find Negative Keywords
1. Google Ads Search Terms Report
Your most important source. The Search Terms Report shows actual queries that triggered your ads. Sort by cost or impressions and look for: high spend with zero conversions, wrong industry queries, or intent mismatch. Review weekly during the first month, then at least every two weeks.
2. Keyword Research Tools
Before launch, anticipate irrelevant traffic. Look for: “Free” + your product, “DIY/how to” + your service, “Jobs/careers” + your industry, competitor names (unless running competitor campaigns).
3. Common Sense Exclusions
- Job-related: jobs, careers, salary, hiring, recruitment, internship
- Free/cheap: free, cheap, discount, coupon, promo code
- DIY/educational: how to, tutorial, course, training, certification
- Research intent: wiki, wikipedia, review, reviews, what is, definition
How to Add Negative Keywords in Google Ads
Method 1: From the Search Terms Report (Reactive)
- Go to Campaigns → [Select Campaign] → Audiences, keywords, and content → Search terms
- Check the boxes next to irrelevant queries
- Click Add as negative keyword
- Choose Campaign or Ad Group level
- Review and adjust match type (consider phrase for broader coverage)
- Click Save
Method 2: From Campaign or Ad Group Settings (Proactive)
- Navigate to Campaigns → [Select Campaign] → Audiences, keywords, and content
- Click Negative search keywords
- Enter keywords one per line using syntax: no wrapper = broad, “quotes” = phrase, [brackets] = exact
- Click Save
Method 3: Via Shared Negative Keyword Lists
- Click the Tools icon → Shared library → Exclusion lists
- Go to Negative keyword lists and click +
- Name your list and add keywords
- Apply to campaigns via Apply to campaigns
How to Build a Master Negative Keyword List
Tier 1 — Universal exclusions (always add):
- free, cheap, low cost, discount
- jobs, careers, employment, hiring, salary, internship
- wikipedia, wiki, quora
- how to, tutorial, diy, training, course, certification
Tier 2 — Industry-specific exclusions: For B2B SaaS: student, school, university, research paper, template, open source, github
Tier 3 — Campaign-specific exclusions: Use ad group or campaign-level negatives to prevent internal cannibalization between campaigns.
Common Negative Keyword Mistakes
- Using broad match negatives too aggressively — can block converting queries accidentally
- Never reviewing the Search Terms Report — new irrelevant queries always emerge
- Adding negatives without checking for conflicts — can block your own ads
- Only adding singular or plural forms — add both variations manually
- Treating negatives as “set it and forget it” — minimum quarterly audit required
Campaign-Level vs. Ad Group-Level Negatives
Campaign-level negatives apply across every ad group within that campaign. Use when a query is irrelevant to all goals of that campaign.
Ad group-level negatives apply only within a specific ad group. Use them to prevent internal cannibalization between ad groups covering similar but distinct themes.
A layered approach works best: account-level shared lists for universal exclusions → campaign-level for theme-specific noise → ad group-level for fine-tuning.
Frequently Asked Questions
How many negative keywords should I have?
There’s no magic number. Small niche accounts might need 50–100. Large accounts with broad keyword sets can easily need thousands. PMax supports up to 10,000.
Do negative keywords affect Quality Score?
Not directly — but they indirectly improve it by ensuring ads only show for relevant queries, which increases CTR and ad relevance.
Can I add negative keywords to Performance Max campaigns?
Yes. As of 2025, you can add up to 10,000 negative keywords to PMax campaigns, and shared negative keyword lists now work with PMax.
How often should I review my negative keyword list?
Weekly during the first month, monthly for established campaigns, quarterly for a full audit.
Conclusion: Stop Losing Budget to Irrelevant Clicks
Negative keywords are the single highest-leverage optimization available to any Google Ads account. They’re free to add, immediate in effect, and compound over time.
- Start with a master negative keyword list before your first campaign goes live
- Review your Search Terms Report every week for the first month, then monthly
- Use phrase match as your default
- Apply a layered approach: account-wide → campaign-level → ad group-level
- Always check for conflicts after adding new batches of negatives
Allable.ai helps you identify wasted spend and surface negative keyword opportunities automatically. Start free and see what your campaigns are actually matching →