Click-Through Rate (CTR)
The percentage of delivered emails whose recipients clicked at least one tracked link.
Definition
Click-through rate (CTR) measures the percentage of delivered emails whose recipients clicked a tracked link. Calculate it as unique clickers divided by delivered emails, multiplied by 100. Click-to-open rate (CTOR) instead divides unique clickers by measured unique opens; the two metrics answer different questions.
Why It Matters
CTR shows how much of the delivered audience takes action. Compare it by campaign type, audience and goal, alongside conversions. CTOR can help examine engagement among measured openers, but privacy prefetch and image blocking make its denominator less reliable.
How It Works
Track unique recipients who click and divide by delivered emails. If 1,000 emails are delivered, 100 recipients register an open and 15 click, CTR is 1.5% and CTOR is 15%. State the denominator when comparing vendor reports, and account for automated security-scanner clicks.
Best Practices
- 1Align your email content with the promise made in the subject line
- 2Place your primary CTA above the fold
- 3Use action-oriented button text instead of generic phrases
- 4Create urgency or scarcity when appropriate and genuine
- 5Reduce friction by minimizing clicks needed to complete the desired action
CTR vs Related Metrics
| Metric | Formula | Best used for |
|---|---|---|
| Open rate | Unique opens / delivered emails | Subject line and sender performance, with privacy caveats |
| Click rate | Unique clicks / delivered emails | Overall campaign action from the full delivered audience |
| Click-through rate | Unique clickers / delivered emails | How much of the delivered audience clicks |
| Click-to-open rate | Unique clickers / unique opens | Engagement among measured openers, subject to tracking limitations |
| Conversion rate | Desired actions / unique clicks or delivered emails | Whether clicks turn into business outcomes |
Click Goals by Email Type
| Email type | Action to measure | Why it differs |
|---|---|---|
| Broad newsletter | Visits to the primary article or resource | Readers may browse without needing to act every time |
| Segmented campaign | Clicks on the relevant offer | Better audience fit usually raises action intent |
| Onboarding email | Completion of the next setup step | The next step is timely and tied to immediate product setup |
| Re-engagement email | A deliberate return or preference update | The audience is colder, so even interested openers need a stronger reason |
CTR Optimization Tests
| Test | What it reveals | Good first variation |
|---|---|---|
| CTA wording | Whether readers understand the value of clicking | Replace generic verbs with outcome-based copy |
| Email length | Whether the page is over-explaining before the action | Short version with one core benefit and one CTA |
| Offer framing | Whether the motivation is practical, urgent, or aspirational | Compare "save time" against "avoid missed revenue" |
| Link count | Whether extra links distract from the main action | One-button version against multi-link version |