Click-through rate (CTR) is the share of people who saw a link, ad, email or button and then clicked it. You get it by dividing clicks by impressions (or views) and multiplying by 100, so 5 clicks from 100 impressions is a 5% CTR.
That formula comes from ad platforms. Google Ads defines CTR as how often people who see your ad end up clicking it, calculated as clicks ÷ impressions.
In email the denominator is usually emails delivered.
On a website it is usually visitors who saw the page or element.
CTR meaning in CRO and A/B testing
In conversion work, CTR is a micro-conversion: a step toward the outcome you care about, not the outcome itself.
Teams use it to measure banners, homepage tiles, menu links, CTA copy and the step from one page to the next.
It is popular because clicks happen far more often than purchases.
A test that needs months to detect a change in conversion rate can often detect a change in CTR within weeks.
Conversionista measured CTR on Fortum's electricity price page for exactly that reason: traffic was too low for a conversion-rate read.
Moving price details into a modal cost 9% in click-through.
The catch is that a higher CTR does not always mean more revenue.
A click is a promise; the next page has to keep it.
If the copy oversells what sits behind the link, CTR goes up and the downstream conversion rate goes down.
Good test plans pair CTR with at least one later metric, such as add-to-cart, sign-ups or revenue per visitor.
Click-through rate examples from real tests
Veeam Software changed a product page link from "Request a quote" to "Request pricing".
CTR to the sales inquiry page went from 0.54% to 1.40%, a 161.66% lift.
The caveat is the one above: it counts clicks to the form, not submitted leads.
NYX Professional Makeup added a line under the buy button saying how many units sold that day.
The purchases message raised buy-button CTR by 43%, and the transaction rate doubled.
Here the click and the sale moved in the same direction, which is what you hope to see.
Clean Commit added badges such as "Best Seller" and "New" to homepage product cards on a Shopify store.
Click-through rose 19% and add-to-cart rate rose 28.3%, but the result was not statistically significant.
A big CTR number from a small sample is a signal to retest, not a win to ship.
Optimizely
Clean Commit
ConversionistaHow to calculate click-through rate
| Channel | Formula | Example |
|---|---|---|
| Search or social ad | clicks ÷ impressions × 100 | 40 clicks ÷ 2,000 impressions = 2% |
| unique clicks ÷ emails delivered × 100 | 300 ÷ 10,000 = 3% | |
| On-site element | visitors who clicked ÷ visitors who saw it × 100 | 540 ÷ 6,000 = 9% |
In an A/B test, compare the CTR of the control and the variant.
If the control gets 9% and the variant 10.8%, the relative lift is (10.8 − 9) ÷ 9 = 20%.
Count each visitor once, and make sure both arms define "saw it" the same way, or the comparison breaks.
Related terms
- Conversion rate: the share of visitors who complete the final goal.
- Lift: the relative change between control and variant.
- Information scent: why link text that matches what's behind it earns clicks that convert.
For tests that moved clicks on buttons and links, see the CTA copy tests or browse all tests and the full glossary.