Type your subject line above and check whether it survives the inbox — most email clients show far fewer characters than you write.
Email Subject Line Display Limits
| Context | Length |
|---|---|
| Desktop clients (Gmail, Outlook) | ~60–70 characters shown |
| Mobile portrait (iPhone Mail) | ~41 characters shown |
| Sweet spot for most audiences | 28–50 characters |
| Preheader text shown | ~40–130 characters |
Limits verified as of July 2026. Platforms change limits occasionally — if you spot one that moved, let us know.
Write for 41 Characters
Over half of email opens happen on phones, where roughly 41 characters survive before truncation. That does not mean every subject must be short — it means the part that sells the open must live in the first 41 characters, with anything after that as bonus context for desktop readers.
Subject Line Tips
- Front-load the value: “Your invoice is ready – March summary inside” survives truncation; the reverse order does not.
- Use the preheader deliberately. It extends the subject — do not waste it on “View in browser”.
- Avoid spam triggers: ALL CAPS, multiple exclamation marks, and “FREE!!!” hurt deliverability more than they help opens.
- Numbers and specifics win: “3 fixes for slow checkout” beats “Improving your store performance”.
Is there a hard character limit for subject lines?
Technically subjects can run hundreds of characters — clients just truncate the display. The practical limit is whatever your recipients' inbox shows, which is why counting at 41 and 60 characters matters more than any maximum.
Do emoji in subject lines hurt deliverability?
Not by themselves — spam filters weigh sender reputation and content far more heavily. Use at most one, place it at the start or end, and remember it occupies one to two characters of your tightest mobile budget.