SMS (Short Message Service) is a text messaging service that allows mobile devices to exchange short text messages. Despite being over 30 years old, SMS remains one of the most widely used communication technologies in the world, with billions of messages sent daily.
How Does SMS Work?
When you send an SMS, your message travels through a complex network of systems:
- Your Phone - Converts your text into a digital signal
- Cell Tower - Receives the signal and forwards it to the carrier’s network
- SMS Center (SMSC) - Stores and routes the message to the recipient
- Recipient’s Carrier - Delivers the message to the recipient’s phone
- Recipient’s Phone - Receives and displays the message
The entire process typically takes just a few seconds, making SMS one of the fastest communication methods available.
SMS vs. Other Messaging Technologies
SMS vs. MMS
| Feature | SMS | MMS |
|---|---|---|
| Content | Text only | Text, images, video, audio |
| Character limit | 160 (GSM) or 70 (Unicode) | Up to 500KB+ |
| Cost | Lower | Higher |
| Delivery | Universal | May vary by carrier |
SMS vs. RCS
RCS (Rich Communication Services) is the next evolution of SMS, offering features like:
- Read receipts
- Typing indicators
- High-quality media sharing
- Group chat improvements
However, SMS still has advantages in terms of universal compatibility and reliability.
Character Limits and Encoding
Understanding SMS character limits is crucial for both personal and business use:
GSM-7 Encoding
- 160 characters per single message
- 153 characters per segment in multi-part messages
- Supports standard Latin characters, numbers, and basic punctuation
Unicode (UCS-2) Encoding
- 70 characters per single message
- 67 characters per segment in multi-part messages
- Required for emojis, special characters, and non-Latin alphabets
Why SMS Still Matters in 2026
Despite the rise of messaging apps like WhatsApp and iMessage, SMS remains vital because:
- Universal Reach - Works on any mobile phone, no app required
- High Open Rates - 98% of SMS messages are read within 3 minutes
- No Internet Required - Works without Wi-Fi or data connection
- Trusted Channel - Used for 2FA, alerts, and official communications
- Business Integration - Easy to integrate with CRMs and marketing platforms
Common Uses of SMS
Personal Communication
- Quick messages to friends and family
- Sharing contact information
- Sending location updates
Business Applications
- Marketing campaigns - Promotions, offers, and announcements
- Customer service - Order updates, appointment reminders
- Two-factor authentication - Security verification codes
- Alerts and notifications - Banking alerts, delivery updates
SMS Marketing Statistics
- 90% of SMS messages are read within 3 minutes
- 45% average response rate for SMS campaigns
- 29% click-through rate for SMS links
- 98% open rate compared to 20% for email
Getting Started with SMS
Whether you’re looking to understand SMS for personal use or explore it for business purposes, the fundamentals remain the same:
- Learn the basics - Character limits, encoding types, delivery
- Understand compliance - TCPA, GDPR, and opt-in requirements
- Choose the right platform - For business use, select an SMS provider
- Test and optimize - Monitor delivery rates and engagement
Conclusion
SMS technology has evolved significantly since its invention in 1992, but its core value proposition remains unchanged: fast, reliable, and universal text communication. Whether you’re sending a quick message to a friend or launching a business marketing campaign, understanding how SMS works helps you communicate more effectively.
For more detailed information on specific SMS topics, explore our guides on SMS Marketing, SMS vs MMS, and SMS APIs.
WhatIsSMS.com
SMS Technology Guide