Quality Score is a number from 1 to 10 that Google reports per keyword, built out of three estimates: how often it expects your ad to be clicked, how closely the ad answers the keyword, and what it makes of the page the click lands on.
It is a diagnostic, not a target. Nothing is charged by it and nothing is directly set by it — but it is the clearest summary Google gives of the half of Ad Rank you can still move when your bid is capped at $2.
Reading the three parts separately
- Expected click-through rate below average: the ad is not answering the search, or it is matched to searches nobody meant.
- Ad relevance below average: the keyword is in the wrong ad group. The ad is written for something else in the same list.
- Landing page experience below average: the click arrives at the home page, or at a page that does not mention what was searched for.
Keywords at 1 or 2 are not a matter of judgement. Ad Grants' mission-based policy requires them to be paused or removed, so an account carrying them is out of policy whatever else it is doing well — and an automated rule that pauses them is the usual way to make sure it stays that way.
Google states this as a requirement rather than a recommendation, at support.google.com/nonprofits/answer/9314402, along with the single-word and overly-generic keyword rules it sits beside.
Questions people ask
What counts as low enough to have to go?
1 and 2. Google's policy names those two and nothing above them — a 3 is weak and allowed, which is worth knowing before an automated rule is written with the wrong number in it.
Does a 10 mean the keyword is working?
It means Google expects the click. Whether the click was worth having is a question about conversions, and the two answers often disagree.
How long does a change take to show?
The score is rebuilt on accumulated data, so a new ad or a new landing page shows up over days of traffic rather than immediately. Judge it on a fortnight, not on an afternoon.
Why does it matter more here than on a paid account?
Because the other half of Ad Rank is capped. A paid account can answer weak quality with a higher bid; a grant account at $2 cannot.