Every Google Ads account pays for some searches it never wanted. A renovation contractor’s ad appears for “renovation jobs”. A tuition centre’s ad shows for “free worksheets”. A clinic in Novena pays for clicks from someone looking for a hospital in Johor Bahru. None of these people will become customers, but each click still costs money.
Negative keywords are how you stop that. This guide explains what negative keywords are and how they work, then focuses on the top 3 negative keyword match types, negative broad, negative phrase and negative exact, because choosing the right type is where most mistakes happen. You will also get starter negative lists for Singapore SMEs, a process for finding new negatives and a simple maintenance routine.
What are negative keywords?
A negative keyword is a word or phrase that stops your ad from showing when it appears in a search. Google’s help page on negative keywords describes them as a way to exclude search terms so you can focus on the keywords that matter to your customers. If you sell new air-conditioners, adding “repair” as a negative prevents your ad from showing to people who need a technician instead.
Negatives work alongside your normal (positive) keywords. Positive keywords say “enter auctions like this”; negatives say “but not these ones”. Together they define which searches you are willing to pay for.
Why negative keywords matter
- Less wasted spend. Budget is spent on searches that can actually produce enquiries.
- Cleaner data. Click-through and conversion rates reflect real prospects, so decisions about bids and copy are better informed.
- More relevant traffic. Fewer irrelevant impressions and clicks generally help your click-through rate, which is one of the signals behind ad quality.
- Better control over broad match. If you use broad match or automated campaign types, negatives are one of your main guardrails. Our guide to keyword research in SEM explains how positive and negative keywords fit together.
How negative keywords behave differently from normal keywords
This is the part many advertisers miss. Positive keywords in Google Ads are matched generously: close variants, synonyms and same-meaning searches can all trigger your ad. Negative keywords are much more literal.
Google states that negative keywords do not match to close variants or expansions. Its own example is that a negative broad match keyword “flowers” blocks the search “red flowers” but does not block “red flower”. So if you want to exclude both singular and plural forms, or obvious synonyms, you need to add each one yourself. Google does note that negatives account for differences in letter case.
The practical consequence: when you add a negative, think through the plural, singular, common misspellings customers actually use and synonyms. For example, excluding job seekers usually needs “job”, “jobs”, “career”, “careers”, “vacancy”, “vacancies”, “hiring” and “salary”.
The top 3 negative keyword match types
We have interpreted “top 3 negative keywords” as the three negative match types Google Ads offers for Search campaigns. Every negative you add uses one of them, and the choice decides how much traffic it blocks.
1. Negative broad match
This is the default when you add a negative without symbols. Your ad will not show if the search contains all the words in your negative keyword, in any order. Searches that contain only some of the words can still trigger your ad.
Example: the negative broad keyword free course blocks “free aircon course” and “course free online”, but does not block “free aircon servicing” or “aircon course”. Use negative broad match for one-word negatives (such as jobs) and for word combinations that are irrelevant in any order.
2. Negative phrase match
Written in quotation marks, such as “second hand”. Your ad will not show if the search contains the exact words in the same order, even with other words before or after.
Example: the negative phrase “second hand” blocks “second hand sofa Singapore” and “buy second hand sofa”, but not “hand made sofa second delivery”. Use it when word order changes the meaning, or when one word alone would block too much.
3. Negative exact match
Written in square brackets, such as [tuition]. Your ad will not show only if the search is exactly those words, in that order, with nothing added. Any extra word lets the ad show again.
Example: a tuition centre might add [tuition] as a negative exact keyword because the one-word search is vague and expensive, while still showing for “maths tuition Bishan” or “sec 3 chemistry tuition”. Use negative exact match for precise exclusions where you do not want to block longer, more specific searches.
Comparing the three match types
| Negative match type | Syntax | Blocks searches that… | Best used for |
|---|---|---|---|
| Negative broad | jobs | contain all the negative’s words, in any order | Single irrelevant words; word sets that are irrelevant in any order |
| Negative phrase | “second hand” | contain the exact phrase in order, with other words allowed | Multi-word phrases where order matters |
| Negative exact | [tuition] | match the negative exactly, with no extra words | Vague or costly searches you want to exclude without blocking longer variants |
A useful rule of thumb: the broader the negative, the more care you need. A single negative broad word such as cheap could block valuable searches if your business competes on price, so check what you would lose before adding it.
Where to add negatives: campaign, ad group, account and lists
Google Ads lets you add negatives at several levels, explained in its guide to adding negative keywords to campaigns:
- Ad group level: blocks a search only for that ad group. Useful for steering searches to the right ad group, for example stopping your general ad group from showing for searches that belong to a more specific one.
- Campaign level: blocks the search across a campaign. The most common place for negatives.
- Negative keyword lists: shared lists you can apply to multiple campaigns at once. Google’s help page on negative keyword lists explains how to create and apply them, which saves time if you run several campaigns with the same exclusions.
- Account level: a set of negatives applied across eligible campaigns in the account, useful for brand-safety terms or exclusions that never apply to your business.
Performance Max campaigns also support negative keywords, though the options and limits differ from Search and have changed over time; check Google’s current help pages before relying on them. Our guide to optimising Performance Max campaigns covers that campaign type in more detail.
Starter negative keyword lists for Singapore SMEs
The lists below are illustrative starting points, not lists to copy wholesale. Remove anything that describes a real part of your business.
- Job seekers: job, jobs, career, careers, vacancy, vacancies, hiring, salary, internship, part time (if you are not recruiting).
- Learners and DIY: how to, tutorial, course, training, diploma, DIY, template, sample, pdf (for service businesses that do not teach).
- Free and bargain seekers: free, freebie, giveaway (if you never offer free services). Be careful with cheap or affordable if price is part of your appeal.
- Wrong location: Malaysia, Johor, JB, Batam, and other cities or countries you do not serve, especially if your location targeting includes people interested in Singapore.
- Wrong product or service: second hand, used, rental, repair or wholesale, depending on what you do not offer.
- Research and complaints: review, reviews, complaint, scam, lawsuit (test carefully; some people searching reviews are close to buying).
Remember to add singular, plural and common local variants, and consider Chinese or Malay terms if your positive keywords are broad enough to match searches in those languages.
How to find new negative keywords
The best source of negatives is your own data. The search terms report shows the actual searches that triggered your ads. Review it regularly and sort by cost: the irrelevant searches that spent the most are your priority.
- Open the search terms report (owner: marketing lead). Choose the last 30 days, or the last 7 days for a new campaign, and sort by cost.
- Mark each term as relevant, irrelevant or unsure. Relevant terms that convert may become new positive keywords.
- For each irrelevant term, find the word that makes it irrelevant. In “aircon servicing course”, the problem is course, so add that rather than the whole search.
- Pick the right match type and level. Use negative broad for single words, phrase where order matters and exact for precise exclusions; add to a shared list if it applies to several campaigns.
- Check for collateral damage. Before saving, search your keyword list and recent converting search terms to make sure the negative will not block anything valuable.
- Note what you added and why. A short log helps if performance changes later.
Other sources include Keyword Planner ideas you rejected during research, customer messages that reveal common misunderstandings, and competitor names you have chosen not to target. Our guide to analysing competitors’ Google Ads covers that decision.
A negative keyword maintenance routine
A small account can keep negatives under control with a light, regular routine.
- Before launch – Build starter lists (owner: marketing lead, 1–2 hours). Create shared lists for job seekers, learners, free seekers and wrong locations, and apply them to relevant campaigns.
- Weeks 1–4 – Review search terms twice a week (owner: marketing lead, 20 minutes each). New campaigns produce the most surprises early on.
- Month 2 onwards – Review weekly (owner: marketing lead, 15–30 minutes). Focus on the highest-cost irrelevant terms.
- Quarterly – Audit your negatives (owner: marketing lead with business owner). Check whether any negative now blocks a service you have since launched, and remove conflicts. Google Ads may flag negatives that conflict with your keywords.
- Before seasonal peaks – Refresh lists (owner: marketing lead). Around Chinese New Year, school holidays and year-end sales, search behaviour shifts and new irrelevant phrases appear.
Track the effect on cost per conversion and conversion rate over time. Our guides to reducing cost per conversion and improving Google Ads conversion rate cover the related levers.
How AI can help manage negative keywords
Search terms reports can run to hundreds or thousands of rows, which makes them a good fit for AI assistance. AI tools can group search terms by theme, flag likely irrelevant patterns (such as job, training or location terms), suggest singular and plural variants and draft a shortlist of candidate negatives with the reason for each. They can also check proposed negatives against your keyword list to warn of conflicts.
Human judgement still matters. An AI tool may not know that your business does offer a rental option, that “cheap” is part of your positioning, or that a Singlish phrase signals buying intent. Treat suggestions as a shortlist, and keep the final decision with someone who understands the business.
Marketing2u’s AI Ads Agent follows this approach: it analyses search terms from a read-only Google Ads connection, highlights wasted spend and suggests negative keywords, using real account data rather than estimates. You review the suggestions and make any changes in your account yourself.
Common negative keyword mistakes
- Adding too-broad negatives. A single word like price or best can block many valuable searches.
- Forgetting plurals and synonyms. Because negatives do not match close variants, “job” does not block “jobs”.
- Blocking your own keywords. A negative that conflicts with a positive keyword stops that keyword from showing.
- Adding the whole search term instead of the problem word. Excluding one long query as exact match blocks only that query.
- Setting and forgetting. Business offers change; a negative added last year may now block a new service.
- Ignoring search terms entirely. Without regular reviews, waste builds up quietly.
Getting started with negative keywords
Negative keywords are one of the simplest, highest-value controls in Google Ads. Understand the top 3 negative keyword match types, broad, phrase and exact, add the variants Google will not cover for you, organise negatives into shared lists and review your search terms report on a steady schedule.
This week, open your search terms report for the last 30 days, sort by cost and add negatives for the five most expensive irrelevant searches. If you want to see how these improvements show up in your numbers, our list of SEM KPIs is a good place to start.
Frequently asked questions
What is a negative keyword in PPC?
A negative keyword is a word or phrase that prevents your ad from showing when it appears in a search. It lets you exclude searches that will not lead to customers, such as job seekers or people looking for free resources. Negatives work alongside your normal keywords to define which searches you pay for.
Do negative keywords block plurals and misspellings?
Google states that negative keywords do not match close variants, so a negative for “job” does not block “jobs”. Add singular, plural and synonym forms yourself. Google does say negatives account for differences in letter case.
How many negative keywords should I have?
There is no ideal number. A new account might start with a few dozen negatives in shared lists and grow from there based on the search terms report. Focus on blocking irrelevant searches that cost money, and check new negatives do not conflict with keywords you want to show for.
Can negative keywords hurt performance?
Yes, if they are too broad or conflict with your positive keywords. A single-word negative such as “price” or “best” can block valuable searches. Review negatives quarterly and remove any that block services you now offer.
Sources and further reading
- Google Ads Help: About negative keywords
- Google Ads Help: About negative keyword lists
- Google Ads Help: Add negative keywords to campaigns
- Google Ads Help: About the search terms report
Related guides
- PPC for Service Businesses: Getting Quality Leads From Google Ads
- The Importance of Keyword Research in SEM
- Cost Per Conversion: 7 Reduction Strategies & Benefits
- How To Improve Conversion Rate In Google Ads: 15 Practical Techniques
- 10 Ways To Optimise Performance Max Campaigns In Google Ads For Real Results
Browse every article in our Paid Advertising guides.