Answer

What's the ideal subject line length for email open rate?

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TL;DR

Question
What's the ideal subject line length for email open rate?
Direct answer
Subject lines under 50 characters display fully on mobile email clients. Beyond 50 characters, the line truncates and the reader sees only the opening. Specificity in the first 30 characters matters more than total length – '5 mistakes founders make' converts better than 'A few mistakes founders make in their funnels and how to fix them'.
Category
email
Last verified
May 19, 2026

Direct answer

Direct answer

As of , the answer is: Subject lines under 50 characters display fully on mobile email clients. Beyond 50 characters, the line truncates and the reader sees only the opening. Specificity in the first 30 characters matters more than total length – '5 mistakes founders make' converts better than 'A few mistakes founders make in their funnels and how to fix them'.

People also ask

What's the ideal subject line length for email open rate?

Subject lines under 50 characters display fully on mobile email clients. Beyond 50 characters, the line truncates and the reader sees only the opening. Specificity in the first 30 characters matters more than total length – '5 mistakes founders make' converts better than 'A few mistakes founders make in their funnels and how to fix them'.

What's the nuance?

Mobile email clients (Gmail iOS, Apple Mail) show 30-50 characters on the preview screen.

What else should I know?

First 3 words carry disproportionate weight in opens – front-load the most specific noun.

What's the common mistake here?

Question subjects ('Did this work for you?') often outperform statement subjects, but only when the question is genuine and answerable.

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