Increase SMS Performance With These 6 A/B Tests

A/B testing is essential in identifying what works best with your subscribers. The variables you test can help guide your SMS strategy and inform future outreach. With A/B testing you may find that SMS always outperforms MMS or certain tones drive more action.

Wondering how to get started? We’ve highlighted 6 ways that you can test your messaging.

Tip: Always test one variable at a time. For example, if you want to test 2 separate images, keep your SMS copy the same. Limiting A/B tests to a single variable makes it easier to identify why one message performed better than another.

Call to action

A “call to action” is a prompt used to direct your subscriber to fulfill an action (example: sign our petition now to demand change!

With A/B testing you can try out different CTA’s to see which variation results in more link clicks, or phone calls. CTA’s should aim to motivate your supporters to take the next step in their advocacy. They can communicate urgency or point subscribers to helpful resources. Try experimenting with your CTA to see which versions drive more action.

Flows vs. Simple message

Test an interactive and non-interactive version to understand how conversational messaging can influence results. Flows are a great way to chat with your supporters at scale and automate data collection, patching calls, and asking questions. But we recommend limiting the number of bot actions in your flows to minimize drop-off. Simple messages do not require a response and can be an effective strategy for sharing updates or links with supporters.


Send versions of your message with and without a file attachment. You may find that including multi-media files (such as GIFs, JPGs, MP3, MP4, VCF, etc.) in your messages will increase or decrease engagement.

Images can be eye-catching, showcase important info, or serve as a branded “cover” for the text portion of your message. But sometimes they can serve as a distraction. Test SMS vs MMS to identify which strategy works best for the nature/topic of your message. It could be the case that one strategy works better for rapid response alerts vs monthly updates.

Different MMS files

If you are planning to send an MMS broadcast, it may be helpful to test different MMS files to see if one of your graphics outperforms the others. You may find that one file drives more action amongst your audience. Identify if certain imagery or certain file types (GIF vs image) yield higher engagement, and use these findings to inform future MMS outreach.

Issue area or Initiative

If your advocacy spans multiple issue areas, you may find messaging your list on certain topics yields varying results. Start out with a CTA destination (like a link to a website or keyword to trigger a call), and create message versions for each key issue area.


As a general rule of thumb, we recommend keeping your message copy to a segment (roughly 160 characters) or less. But depending on your broadcast topic, a longer message may do a better job at organizing your base and sharing important information.

Try experimenting with different message lengths by first drafting your long-form message and then simplifying the message to the shortest length possible. You may find that certain details or examples in your long-form message will resonate with your audience. Alternatively, results may show that longer messages yield high drop-off  — making short messages the way to go.

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