Find your best email send time
Answer 5 questions for a personalized recommendation backed by 150B+ emails of platform data. Then see what timing actually does to your inbox position.
Question 1 of 5
What’s your primary goal when you hit send?
Your recommendation is a starting point. But what happens when you get the timing wrong?
Your recipient checks their inbox at 8:00 AM
inbox position when your reader checks at 8 AM
BuriedBefore you A/B test send times, make sure you have the statistical power to detect a difference.
Required / variant
17,514
Variants possible
—
Sends needed
~4
Your list of 10,000 would need ~4 weekly sends (~4 weeks) to accumulate enough data for a 2-variant test detecting a 20% lift in click rate.
Two-sided test, \u03B1 = 0.05, 80% power. Based on a two-proportion z-test.
These tools are built on 150B+ emails of real data
Read the full breakdown — day-by-day platform comparisons, industry benchmarks, generational patterns, timezone strategies, and the complete testing framework.
Frequently asked questions
What is the best day to send an email newsletter?
Tuesday is the highest-consensus day across 10 major platforms covering 150B+ emails. Thursday ranks second for engagement and ties for first in conversion rates. Friday is the emerging leader for B2C and ecommerce — MailerLite’s 2026 data shows Friday producing the highest open rate (49.72%) and click rate (8.09%). Saturday is the worst day across every platform studied.
What is the best time to send an email?
It depends on your goal. For opens and visibility, 8:00–11:00 AM in your recipients’ local time zone is the safest window — 10:00 AM is the single highest-consensus time. For clicks and conversions, 5:00–9:00 PM performs better, as readers have more time to browse and act during evening hours.
Does send time really affect email open rates?
Yes, but open rates are unreliable in 2026 due to Apple Mail Privacy Protection, which pre-fetches tracking pixels and inflated unique open rates by 24.8%. Click-through rates are the trustworthy signal for measuring timing effects. When optimizing send time, measure clicks or conversions — not opens.
How many subscribers do I need to A/B test send time?
More than most people think. Detecting a 20% relative lift in a 2% click rate requires roughly 20,800 recipients per variant. Lists under 10,000–20,000 are almost certainly underpowered for single-send timing tests. Smaller lists should either test across multiple sends or activate AI send time optimization instead.
What is AI send time optimization (STO)?
STO systems predict the best delivery time for each individual subscriber based on their historical engagement patterns. Instead of blasting your entire list at 10 AM, each person receives the email at their personally optimal time. Platforms like Klaviyo, HubSpot, and Brevo offer STO, typically requiring 10,000–12,000+ active profiles and 3–6 months of engagement history.
Should I send my newsletter on weekends?
Generally no. Saturday is the worst-performing day across every platform studied, and Sunday is second-worst for most metrics. The one exception: Sunday evening between 6:00–9:00 PM is a strong window for ecommerce, when consumers plan their upcoming week and are receptive to last-chance offers and abandoned cart reminders.
Great timing starts with great content
Nutshell turns your RSS feeds into AI-curated newsletters. Your audience gets one clean email with the content that matters — sent at the right time.
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