Character Analysis
Type a message to see character analysis
Segment Breakdown
Segments will appear here
SMS Encoding Reference
| Encoding | Single SMS | Multi-part SMS | Use Case |
|---|---|---|---|
| GSM-7 | 160 characters | 153 chars/segment | English, most European languages |
| Latin-1 | 140 characters | 134 chars/segment | Extended European (accented chars) |
| UCS-2 | 70 characters | 67 chars/segment | Emoji, Chinese, Arabic, Hebrew, etc. |
GSM-7 Extended Characters
These characters are part of GSM-7 but count as 2 characters because they require an escape sequence:
Tips to Reduce Segment Count
- Avoid emoji — A single emoji forces UCS-2, cutting your character limit in half
- Watch extended chars — Characters like
{}[]count as 2 - Use standard quotes — Replace curly quotes (“ ”) with straight quotes (" ")
- Avoid smart punctuation — En-dash (–) and em-dash (—) force UCS-2
- Link shorteners — Use short URLs to save characters
Why Segments Matter
SMS carriers charge per segment, not per message. A 161-character GSM-7 message costs the same as a 306-character message (both are 2 segments). Understanding segments helps you:
- Optimize costs by staying within segment boundaries
- Predict delivery behavior for long messages
- Avoid unexpected charges from emoji or special characters
Multi-Part Message Overhead
When a message exceeds a single segment, each segment includes a User Data Header (UDH) that takes 6-7 bytes. This header tells the receiving device how to reassemble the parts. That's why multi-part segments hold fewer characters:
- GSM-7: 160 → 153 (7 chars for UDH)
- Latin-1: 140 → 134 (6 chars for UDH)
- UCS-2: 70 → 67 (3 chars for UDH)
Need API Access?
- Identify the exact messaging provider for any phone number before you send — prevent deliverability surprises
- Messaging Provider Lookup at $0.0009 per query, bundled with LRN and carrier data
- Available via REST or GraphQL — integrate directly into your SMS campaign workflow
SMS & Messaging Provider API — FAQ
What is a messaging provider lookup and how does it relate to SMS segments?
A messaging provider lookup identifies the specific SMS gateway or carrier that will deliver a message to a given phone number. Knowing the messaging provider before sending lets you choose the right aggregator or routing path, which directly affects whether a multi-segment message is delivered intact or truncated by carrier filtering.
Can I use the VRI API to identify messaging providers for my SMS campaigns?
Yes. The VRI Messaging Provider Lookup API returns the SMS gateway provider for any US phone number at $0.0009 per query. It can be called alongside LRN lookup to get carrier name, line type, and messaging provider in a single workflow — useful for routing high-volume A2P campaigns through the optimal path for each recipient's carrier.
How does messaging provider identification improve SMS deliverability?
Different carriers and messaging providers apply different filtering rules, rate limits, and segment reassembly behavior. By identifying the messaging provider upfront, you can route messages through the right gateway, apply carrier-specific message formatting, and avoid sending multi-segment UCS-2 messages to providers that don't support long message reassembly — reducing both cost and deliverability failures.
SMS API for Developers
Send SMS programmatically with delivery insights. Integrate with your existing systems.