The SMS character limit is 160 characters per message — but add a single emoji or special symbol and that limit silently drops to 70 characters. Go over the limit and your text doesn’t fail; it splits into multiple “segments” of 153 characters each (67 with emojis), and if you’re sending marketing or business SMS, you pay for every segment.
This one limit dates back to a 1985 engineering decision and still controls the cost of every text campaign in 2026. This guide explains where 160 comes from, the emoji trap that doubles your sending costs, and how to count your message the way carriers do — which you can check instantly in the free Text Character Counter.
What Is the SMS Character Limit?
A single SMS is limited to 160 characters when using the standard GSM-7 alphabet — the basic Latin letters, digits, and common punctuation defined in the GSM standard. The number isn’t arbitrary: in 1985, engineer Friedhelm Hillebrand determined that most short messages fit within 160 characters, and the signaling channel SMS piggybacked on had 140 bytes of room — 140 bytes × 8 bits ÷ 7 bits per GSM character = exactly 160 characters.
That 140-byte container is the key to everything else about SMS limits.
Why Does One Emoji Cut the Limit to 70 Characters?
Because emojis (and characters like á, ü, ñ, curly quotes “ ”, em dashes —, and most non-Latin scripts) can’t be encoded in GSM-7. The moment your message contains even one such character, the entire message switches to UCS-2 encoding, which uses 16 bits per character:
140 bytes ÷ 2 bytes per character = 70 characters.
The brutal part: it’s all or nothing. A 155-character message that’s fine in GSM-7 becomes a 3-segment message the instant you add a single 🎉. Common stealth triggers that flip your encoding without you noticing:
- Curly/smart quotes and apostrophes (’ instead of ‘) — word processors insert these automatically
- Em dashes (—) pasted from a doc
- Accented names (José, Zoë)
- Any emoji, including ones inside pasted templates
SMS Segment Limits in One Table
When a message exceeds one SMS, carriers split it into segments, and each segment loses a few characters to the header that stitches the parts back together:
| Encoding | Single Message | Per Segment (Multi-Part) | 2 Segments Hold | 3 Segments Hold |
|---|---|---|---|---|
| GSM-7 (plain text) | 160 characters | 153 characters | 306 | 459 |
| UCS-2 (emoji/Unicode) | 70 characters | 67 characters | 134 | 201 |
Also worth knowing: some GSM-7 characters count as 2 characters even in plain-text mode — the extended set including { } [ ] ~ ^ \ | and the € symbol.
Why Do SMS Segments Cost You Money?
Business SMS platforms (Twilio, and virtually every SMS marketing tool) bill per segment, not per message. Your recipient sees one long text; the carrier — and your invoice — sees two or three:
- A 161-character plain-text message = 2 segments = double cost.
- A 160-character message with one emoji = 3 segments (160 ÷ 67, rounded up) = triple cost.
At campaign scale this is real money: sending 50,000 messages that accidentally run 2 segments instead of 1 doubles that send’s cost for zero extra value. The fix costs nothing: count before you send, keep marketing texts under 160 GSM-7 characters (or under 70 if the emoji is essential), and strip smart quotes from anything pasted out of a document.
Paste your SMS copy into textcharactercounter.com/ to see the exact character count — and scan for sneaky characters like ’ and — before they flip your encoding.
5 Rules for Writing Texts That Fit in One Segment
- Target 140, not 160. Personalization fields ({first_name}) expand at send time; a 20-character buffer keeps “Alexandria” from splitting your message.
- Replace smart punctuation. Straight quotes (‘), hyphens (-), and three dots (…) instead of ’ — and ….
- Decide if the emoji is worth 90 characters. That’s effectively what it costs (160 → 70).
- Front-load the offer. Even in one segment, the first few words determine whether the text gets read or swiped away.
- One link, shortened. Long URLs devour the budget; a short branded link leaves room for the message.
What About iMessage, WhatsApp, and RCS?
The 160-character limit applies to true SMS only. Modern messaging protocols have far higher ceilings — iMessage and WhatsApp effectively don’t constrain normal messages, and RCS (the successor to SMS on Android) supports thousands of characters. But business text messaging still rides on SMS for universal reach, and any message that falls back from RCS/iMessage to SMS (no data, non-supported handset) hits the 160/70 rules again. If you write for campaigns, write for SMS.
Frequently Asked Questions
What is the SMS character limit?
160 characters per message using standard GSM-7 text. Messages containing emojis or special Unicode characters are limited to 70 characters.
Why are text messages limited to 160 characters?
The SMS standard reserved 140 bytes per message; at 7 bits per GSM character, that equals exactly 160 characters — a limit set in 1985 that still applies today.
What happens if a text exceeds 160 characters?
It’s split into segments of 153 characters each (67 for emoji messages) and reassembled on the recipient’s phone. SMS platforms bill per segment.
Why does one emoji shorten my SMS limit?
An emoji forces the whole message into UCS-2 encoding at 16 bits per character, cutting capacity from 160 to 70 characters.
Do spaces count in SMS character limits?
Yes — every character counts, including spaces and punctuation. Some symbols like { } [ ] € count as two characters even in plain text.
How do I check my SMS character count?
Paste the message into a free character counter like textcharactercounter.com/ before sending — and watch for smart quotes and em dashes that trigger the 70-character emoji limit.
Conclusion
SMS gives you 160 characters — or 70 the moment anything non-standard sneaks in — and every segment past the first costs you money at scale. Count first, strip the smart quotes, and make the emoji earn its 90-character price tag.
Check your next campaign message in the free Text Character Counter before your SMS platform’s invoice checks it for you.