Back to Glossary
Metrics & Analytics

Unique Opens

The count of individual recipients who opened an email, regardless of how many times they opened it.

Definition

Unique opens measure the number of individual recipients who opened an email at least once, regardless of how many times they opened it. This differs from total opens, which counts every open including multiple opens by the same person. Unique opens provide a cleaner measure of audience reach.

Why It Matters

Unique opens more accurately represent how many people engaged with your email. Total opens can be inflated by recipients who open multiple times or email security tools that open emails. For calculating open rate, unique opens divided by delivered emails gives a cleaner percentage.

How It Works

When tracking pixels fire, the email platform records each open event. Unique opens count each recipient once, even if they open 10 times. Total opens count all 10. Most email platforms report both, with unique opens being the primary metric for open rate calculation.

Best Practices

  • 1Focus on unique opens for open rate calculation
  • 2Use total opens to understand re-engagement behavior
  • 3Account for Apple MPP effects on unique opens
  • 4Complement open data with click metrics
  • 5Track unique opens over time for trend analysis

Frequently Asked Questions

For open rate calculation and audience reach, use unique opens. Total opens are useful for understanding how engaging your content is - emails that get opened multiple times are being referenced or re-read. Both have value for different insights.

Apple Mail Privacy Protection pre-fetches tracking pixels, counting as opens even when emails are not actually read. Security tools may also trigger opens. Filter for MPP-affected opens when possible for more accurate data.