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The Mon SMS Gratuit team15 November 20251 min read
The famous 160-character SMS limit is no accident: it dates back to the very origins of the GSM standard, in the late 1980s.
A historical technical constraint
The SMS format was designed to fit inside the GSM network's signalling channels, which had limited space. Engineer Friedhelm Hillebrand estimated that 160 characters were enough for most short messages — and that standard never changed.
The 7-bit GSM alphabet
A regular SMS uses the 7-bit GSM alphabet, which encodes each character on 7 bits. That allows 160 characters per message. If you use special characters (emojis, some accents), the message switches to UCS-2 (16-bit) and the limit drops to 70 characters.
Our tips
- Stay under 160 characters to send in a single SMS; beyond that the message is split into segments of 153 characters.
- Avoid emojis if you want to keep the higher limit.
- French accents are often converted automatically to stay within 7-bit GSM.
On Mon SMS Gratuit, the character counter shows you in real time how many characters you have left before reaching the limit.
#SMS#160 characters#Technical
