A negative keyword is a term you tell Google Ads never to match. Add "free" as a negative and any search containing that word stops triggering your ads. It is the cheapest lever in a search account and the easiest one to pull too hard: a negative added at the wrong match type takes converting traffic out with the waste.
What is a negative keyword?
A negative keyword is an exclusion. Where a keyword tells Google which searches should trigger your ad, a negative tells it which ones should not. Negatives never trigger anything, never cost anything, and never appear in your keyword performance — they only subtract. You can add them to an ad group, a campaign, or a shared list applied to many campaigns at once.
Where negatives live
Level matters more than most accounts treat it. The same word blocked one level too high quietly kills traffic somewhere you were not looking.
Start at campaign level for anything you found in a search terms report. Promote a term to a shared list once you have blocked it in a third campaign — that is the signal it belongs to the account, not to one offer.
Negative match types are not keyword match types
This is the part that causes the damage. Negatives behave differently from the keywords with the same match type names.
Two rules follow from that table, and they are the two most people get wrong.
Negatives do not match close variants. A keyword on broad match will happily pick up plurals, misspellings and synonyms. A negative will not. Block "sneaker" and "sneakers" still runs. If a misspelling is costing you money, the misspelling has to be added by hand.
A broad negative is an AND, not an OR. The negative "free shoes" does not block every search containing "free". It blocks searches containing "free" *and* "shoes". If you want everything with "free" gone, the negative is the single word.
Find the candidates
The queries worth blocking are already in your account. The filter is the same one that finds the search terms wasting your money: spent more than your threshold in the last 30 days, converted zero times. What changes here is the output — you want the negatives, the match types and the levels, not just the list of offenders.
If your assistant is connected to the account, it is one message.
Pull my Google Ads search terms report for the last 30 days. Find every term that spent more than $20 and converted zero times. Group them by intent: clearly irrelevant, competitor, informational, and potentially valuable but unproven. For the clearly irrelevant group only, propose the exact negative keywords I should add, and for each one give me the match type (broad, phrase or exact) and the level (ad group, campaign, or shared list) with one sentence of reasoning. Check each proposed negative against my active keyword list and tell me if it would block any keyword I am currently bidding on. Do not apply anything.
Change the twenty to a number that means something on your account. It should be roughly what you would pay for a customer, not a round number you liked the look of.
The check against the active keyword list is the important half of that prompt. A negative that conflicts with a keyword you are bidding on wins — Google honours the exclusion and the keyword simply stops serving, with no warning anywhere in the interface.
Apply them
Once you have read the list and struck anything you disagree with, the second message applies what survived.
Add the negative keywords we agreed on, at the match types and levels you proposed. Show me the exact list you are about to add and which campaign or list each one lands in, then wait for my confirmation before writing anything.
Nothing in the account moves until you say so. That is the whole approval model, and it matters most on this job: negatives are the one change that removes traffic silently. A bad budget change shows up as a spend spike the next morning; a bad negative shows up as nothing at all.
A starter list worth stealing
Most accounts share the same first fifty. These belong on a shared list applied to every search campaign, unless one of them is genuinely your business.
- Free intent — free, freeware, gratis, no cost, trial version
- DIY and instructional — how to make, do it yourself, tutorial, template, sample
- Job seekers — jobs, salary, hiring, career, internship, resume
- Cheap intent, if you are premium — cheap, cheapest, discount, coupon, promo code
- Second hand — used, refurbished, second hand, ebay, craigslist
- Study and research — meaning, definition, wikipedia, reddit, pdf, case study
- Adult and unrelated verticals — whatever the search terms report keeps dragging in
Add competitor names deliberately rather than by reflex. Bidding on competitor terms is a legitimate strategy; blocking them is a decision, not hygiene.
Where negatives cannot reach
Not every campaign type takes them, and this catches people out.
- Performance Max takes account-level negative keyword lists and campaign-level negatives, but there is no search terms report at the query level you are used to. You are excluding on partial information.
- Shopping campaigns take negatives normally, but your product titles do the matching, so a negative often treats a symptom whose cause is in the feed.
- Demand Gen and Display do not run on search queries at all. Negative keywords there are content exclusions, which is a different mechanism with a different effect.
If most of your budget is in Performance Max, the negatives conversation is a smaller lever than it looks. What actually works in AI Google Ads management covers where the real controls moved.
Three mistakes worth avoiding
Blocking a research query on a considered purchase. Somebody comparing options costs you clicks for three weeks and then converts on a branded search. Block them and you buy a cheaper cost per acquisition and a smaller business.
Acting on three clicks. Three clicks with no conversion is noise. Wait for enough spend that the zero means something.
Adding negatives and never reading them again. Lists rot. A negative added during a product line you no longer sell is still blocking traffic two years later. Re-read the shared list once a quarter.
Make it a habit
Loose match types keep serving new queries, so the list refills after every clean-up. Weekly is right for an account that spends every day; monthly is enough for a small one. The weekly Google Ads review folds this check into a routine you can run in ten minutes, and the 30-minute audit covers the other six places money leaks.