SMS text messages use two encoding standards depending on the characters you type. Standard GSM-7 encoding allows up to 160 characters per message segment and covers the Latin alphabet plus common symbols. The moment you add an emoji, smart quote, or any character outside the GSM-7 set, the entire message switches to UCS-2 Unicode encoding, which cuts each segment to 70 characters. Multi-segment messages reserve space for concatenation headers, reducing usable characters to 153 (GSM-7) or 67 (UCS-2) per segment. Use this SMS Character Counter to stay within each limit and avoid unexpected per-message billing. The SMS preset is pre-activated below.