# 160 characters: writing an effective SMS for a free send

> The 160-character limit forces you to get to the point. Our tips for writing a clear message and sending it for free in a few seconds.

- Source: https://www.envoyer-sms-gratuit.com/en/blog/2025-11-15/sms-160-character-limit
- Published: 2025-11-15 (15 November 2025)
- Author: L'équipe Envoyer SMS Gratuit
- Language: en
- Categories: Guide
- Tags: Free SMS, SMS format, Copywriting

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Sending a free SMS to a French mobile, straight from your browser and without signing up: it's simple, but a good message takes some thought. A standard SMS fits within **160 characters**, and that constraint is actually an ally. It forces you to say what matters, without detours.

## Why 160, and not one more

This limit comes from the GSM standard. A message travels in 140 bytes, and the [GSM-7 alphabet](/glossaire/gsm-7) encodes each character on 7 bits — which works out to 160 signs. As soon as a character falls outside that table, the message switches to [UCS-2 encoding](/glossaire/ucs-2) and the ceiling drops to 70 characters. Good to know when you're trying to fit as much information as possible into a single send.

## What it changes when you write

Beyond 160 characters, the message is split into [concatenated segments](/glossaire/concatenated-sms) and then reassembled on the recipient's phone. Nothing blocking, but each segment loses a little room, and a short message stays more readable. Writing within the limit of a single SMS also means keeping control over the final result.

## Three useful habits

1. **Get to the point right from the start.** The notification preview should convey the meaning without even opening the message.
2. **Avoid rare characters** (certain symbols, emojis, or unusual accented letters) that flip the whole message into UCS-2 and cut the available space in half.
3. **Count before you send.** Our [character counter](/outils/compteur-caracteres-sms) shows you the length and encoding in real time.

Need a complete walkthrough? Follow the guide to [write an SMS in 160 characters](/guides/write-an-sms-in-160-characters). With **Envoyer SMS Gratuit**, a short, precise message goes out to any French mobile (06 or 07) in a few seconds — no ads, no limits, and no sign-up.