Search ad copy runs on tight character limits — roughly 30 characters per headline, 90 per description, and around 270 for sitelink descriptions. These aren’t just technical constraints; they’re a forcing function for clarity. If your value proposition can’t be expressed in a 30-character headline, it isn’t distilled enough yet. Writing to the limits produces sharper messaging that also happens to fit.
- ▪Search ads cap headlines at ~30 characters, descriptions at ~90.
- ▪Sitelink descriptions run to roughly 270 characters.
- ▪The limits force you to distill the value proposition.
- ▪If it won’t fit a headline, it isn’t sharp enough yet.
- ▪Write to the constraint and the clarity carries everywhere.
Marketers treat ad character limits like a cage — a frustrating box that won’t hold their brilliant message. That’s backwards. The 30-character headline is one of the best editors you’ll ever work with, because it refuses to let you hide a fuzzy value proposition behind extra words.
Learn the limits, then use them as a discipline rather than an obstacle.
The limits that matter
Know them cold so you write to fit from the first draft, not after.
- Headlines: ~30 characters each — the workhorses, where the offer must land.
- Descriptions: ~90 characters each — room for one supporting idea, not a paragraph.
- Sitelink descriptions: ~270 characters total across two lines — context, not an essay.
- The rule of thumb: one idea per asset, expressed as tightly as possible.
Why the constraint improves the copy
A 30-character limit is unforgiving to vagueness. “Solutions to transform your business” doesn’t fit and doesn’t mean anything; “Payroll for restaurants” fits and says exactly what you do. The constraint strips out the filler adjectives and forces the specific, concrete claim underneath — which is the claim that actually converts.
| Over the limit / vague | Under 30 / specific | |
|---|---|---|
| “Transform your workflow today” | Vague filler | “Project mgmt for agencies” |
| “Unlock your growth potential” | Says nothing | “Cut your CPA by tracking” |
| Reads as | Generic | Concrete |
How to write to it
Start from the plainest statement of what you offer and who it’s for, then cut until it fits. Lead each headline with a distinct idea — offer, proof, differentiator — rather than repeating the same claim three ways. And write the description to support the headline with one concrete detail, not to restate it. If a line won’t fit, that’s usually a sign the idea isn’t distilled yet.
Does your value prop survive the cut?
Take your core message and try to write it as a 30-character headline. If you can’t without losing the meaning, the problem isn’t the limit — it’s that the message hasn’t been sharpened enough. Fix that, and clearer copy follows everywhere else too.