Email subject line insights
Email subject line examples
Compare short, vague, clear, and overlong subject lines to see what gets opened.
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Side-by-side examples make the pattern obvious: vague subject lines hide the point, long ones get truncated, and clear ones tell the reader what is inside. Use the checker to test your own subject line, then move into the generator when you want to draft the reply.
This may be why you're not getting opens. Vague or long subject lines are easy to skip.
Practical examples
Side-by-side subject line examples
Too vague
Quick question No topic or outcome, so the open feels optional.
Clearer
Need budget approval by Friday Specific enough to set context quickly.
Too long
Following up on revised deck and stakeholder timeline for next week Too much setup for an inbox preview.
Better
Revised deck approval needed by Friday Short, specific, and easy to act on.
Common mistakes
Watch for these traps
No contrast
If every example looks the same, it is hard to learn what changes the open rate.
Generic phrasing
Quick question, update, or hello gives the reader nothing to anchor on.
Too much setup
Long openers bury the real reason to open the message.
What works for subject lines
What works?
These subject lines get opened:
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RepliStack's Subject Line Checker helps you see whether a subject line is too vague, too long, or specific enough to earn an open.
Related pages
Dive into related subject line insights
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