Subject line grader.
Score length, readability, sentiment, and spam triggers as you type.
- Price
- Free, no signup
- Category
- Content
The score updates as you type.
Common questions.
What makes a subject line score high?
High scores come from clear language, strong readability, and minimal spam signals.
What is the best subject line length?
Most inboxes show 20 to 60 characters, so stay in that range when possible.
Do emojis help open rates?
Emojis can help when relevant, but overuse may hurt deliverability or readability.
Should I use personalization?
Yes. Simple personalization often improves engagement when data is accurate.
Write it here. Send it from Bento.
Marketing, automation, and transactional email in one app. Plans start at $29/mo for up to 5,000 Active Users.