SMS Marketing Blog | Subtext

A/B Testing for SMS: Improve Messaging Performance | Subtext

Written by Subtext | Jun 9, 2026

Text messaging is a high-attention, high-stakes channel. Messages are opened and seen almost immediately, which makes every text highly visible. Small differences in wording, tone, or structure can have a meaningful impact on engagement and action.

As teams get better at reaching the right audience, the next challenge becomes clear: knowing what message will actually perform.

Today, we are introducing A/B Testing, a new capability designed to help teams answer that question and improve results with every send.

In a channel where messages appear directly on someone’s phone, every message needs to earn its place.

What Is A/B Testing?

A/B Testing is a built-in workflow in the Broadcast Composer that allows teams to test two versions of a message, compare performance, select a winning version, and automatically send it to the rest of the audience.

Instead of choosing a message based on instinct, teams can validate performance before sending at scale.

With A/B Testing, you can:

  1. Create two versions of a message
  2. Send each version to a small portion of your audience
  3. Compare performance results side by side
  4. Send the winning version to everyone else

Testing and distribution happen in a single workflow.

What Problem Does This Solve?

With tools like Audience Import and Audience Groups, teams can bring in their audience and target it more effectively.

But even with strong segmentation, messaging decisions are often based on assumptions:

  • Which version of a message will resonate
  • What framing will drive engagement
  • What will lead to action versus being ignored

In a high-attention channel, these decisions directly impact results.

A/B Testing solves the “what should I send?” problem by helping teams evaluate messaging before it is sent broadly.

What You Can Test

A/B Testing allows teams to experiment with the parts of a message that influence performance.

Common use cases include:

Message framing
Test two versions of a headline or opening line to see which drives more engagement.

Tone and style
Compare a direct message with a more narrative or conversational version.

Calls to action
Test an offer-driven message against a value-driven message.

Message structure
Evaluate differences such as short versus long messages or the use of emojis.

These tests make it possible to evaluate messaging decisions using real audience behavior.

Why This Matters

Without structured testing, messaging performance is difficult to improve consistently.

Teams often rely on intuition or isolated results, making it harder to identify patterns in what works.

With A/B Testing, teams can:

  • Validate messaging decisions before full distribution
  • Improve performance within a single campaign
  • Build a clearer understanding of what resonates with their audience
  • Apply those learnings to future sends

Over time, this creates a feedback loop where each campaign contributes to better performance across the program.

Examples Across Use Cases

Below are examples of how different teams use A/B Testing to improve messaging performance.

1. Publishers

Use Case: Optimizing Breaking News Alerts

A publisher sending a breaking news alert might test:

Version A
A direct, factual headline

Version B
A more urgency-driven or curiosity-based headline

The system sends both versions to a small portion of subscribers, measures engagement, and automatically sends the selected winning version to the rest.

Result: Higher click-through rates on time-sensitive content and clearer insight into which headline styles consistently drive engagement.

2. E-Commerce

Use Case: Driving Revenue from Product Recommendations

An editorial commerce team might test:

Version A
A direct product recommendation with a clear value statement

Version B
A scarcity or urgency-driven message highlighting why the product is worth attention now

The system sends both versions to a small portion of subscribers, measures performance, and automatically sends the selected winning version to the rest.

Result: Higher click-through and conversion rates on product recommendations and clearer insight into which messaging drives purchasing behavior.

3. Creators

Use Case: Improving Product Launch Messaging

A creator announcing a new product might test:

Version A
A high-energy launch message focused on excitement

Version B
A story-driven message explaining the product and its value

The system measures engagement and automatically sends the selected winning version to the full audience.

Result: Increased sales at launch and a better understanding of which messaging style resonates most.

4. Marketing Teams

Use Case: Driving Conversions

A marketing team targeting a high-intent segment might test:

Version A
A direct promotional offer

Version B
A value-focused message highlighting benefits

The system highlights performance results and automatically sends the selected winning version to the rest of the audience.

Result: Higher conversion rates and improved campaign performance over time.

Built Into the Messaging Workflow

A/B Testing is designed to work within the existing broadcast workflow. The goal is not just to generate insights. It is to improve performance within the same campaign.

There is no need for external tools or manual audience setup:

  • Audience splits are handled automatically
  • Testing happens directly in the Broadcast Composer
  • Performance is measured in one place
  • The winning version is distributed automatically once a winner is selected

This allows teams to test and improve messaging without adding complexity.

From Messaging to Performance

A/B Testing adds a performance layer on top of audience targeting and activation.

Once teams are reaching the right audience, the next step is improving what they send. Over time, each campaign contributes to a clearer understanding of what messaging performs best, helping improve results across future sends.

Getting Started with A/B Testing

A/B Testing is available directly within the Broadcast Composer.

Create two message variants, define your test audience, and run your send. The system handles testing, measurement, and distribution of the winning version.

If you are already using Subtext, you can start testing your next message immediately.

If you are new to Subtext and want to see how performance-driven messaging can improve engagement and conversions, schedule a demo to learn more.