What is SMS character encoding?

SMS (Short Message Service) uses two main encoding types to transmit text messages: GSM-7 and Unicode (UCS-2). GSM-7 is a 7-bit encoding that supports basic Latin characters, numbers, and common symbols, allowing up to 160 characters in a single message. When you use characters outside the GSM-7 alphabet—like emojis, Cyrillic, or Chinese characters—your phone automatically switches to Unicode encoding, which only allows 70 characters per message. Understanding these limits is crucial for planning SMS campaigns and avoiding unexpected message splitting.

Tool description

SMS Character Counter is a specialized tool that analyzes your text message and shows exactly how it will be transmitted via SMS. It automatically detects whether your message uses GSM-7 or Unicode encoding, calculates the total character count, shows how many SMS parts your message will be split into, and displays the remaining character budget. The tool provides a real-time preview of each message part, helping you optimize your text to minimize costs and ensure your message is delivered as intended.

Features

  • Automatic encoding detection (GSM-7 vs Unicode/UCS-2)
  • Real-time character counting with extended character support
  • Message split calculation and preview
  • Remaining character counter
  • Visual display of each SMS part
  • Support for special characters and emojis

Use cases

  • Planning bulk SMS campaigns to estimate costs accurately
  • Optimizing marketing messages to fit within single SMS limits
  • Testing international messages with Unicode characters
  • Verifying how long messages will be split before sending
  • Ensuring critical information stays in the first SMS part