Postscript Review
Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email
Last updated 2026-04-08
Our verdict
The specialist SMS platform for Shopify. If SMS is a serious revenue channel for your store, Postscript's AI testing and conversational commerce features give it an edge over the SMS add-ons in Klaviyo and Omnisend.
Last reviewed: by Mark Dunne
TL;DR
Postscript scores 7.5/10 for e-commerce sellers. It offers a free plan to get started. Postscript is the SMS marketing platform built for Shopify. Deeper SMS features than Klaviyo, with AI-powered message testing and conversational commerce. Free Starter plan with pay-per-message pricing. Shopify and US/Canada only.
Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email. How we test tools
What Does Postscript Do?
Postscript is an SMS and MMS marketing platform built exclusively for Shopify stores. You send promotional texts, set up automated flows (abandoned cart, post-purchase, winback), and build subscriber lists through opt-in popups and checkout integration.
What separates Postscript from the SMS features in Klaviyo or Omnisend is depth. The Infinity Testing feature tests thousands of message variants automatically to find what converts best. Shopper AI enables two-way conversations where the AI handles customer questions and recommends products via text.
The pricing model is pay-per-message on top of a monthly platform fee. Starter is free but requires $49/month minimum spend on messages. Growth and Professional have higher platform fees but lower per-message costs.
How Does Postscript Score?
How Much Does Postscript Cost?
Platform fee plus per-message costs. Carrier fees apply on top of message costs. SMS is cheaper than MMS. US and Canada only for delivery. The total cost depends heavily on message volume.
Starter
$0/mo
Growth
Recommended$100/mo
Professional
$500/mo
Enterprise
Contact sales
Platform fee plus per-message costs. Carrier fees apply on top of message costs. SMS is cheaper than MMS. US and Canada only for delivery. The total cost depends heavily on message volume.
What Features Did We Test?
Shopify integration
Best in categoryBuilt exclusively for Shopify with deeper integration than any other SMS tool. Subscriber sync, checkout opt-in, order data for targeting - it all works seamlessly because Shopify is the only platform Postscript supports.
Infinity Testing (AI)
Works wellTests thousands of message variants automatically. Different copy, emojis, timing, offers - the AI finds what converts best without you manually setting up A/B tests. This is the standout feature.
Automated flows
Works wellAbandoned cart, welcome series, post-purchase, browse abandonment - the standard flows are ready to activate. Similar to Klaviyo flows but SMS-specific with better message templates.
Shopper AI (conversational)
AcceptableTwo-way texting where AI handles customer questions and recommends products. Works for simple queries but struggles with complex questions. A promising feature that needs more polish.
Subscriber growth tools
Works wellPopups, checkout opt-in, keyword opt-in, QR codes - multiple ways to build your SMS list. The Shopify checkout integration captures subscribers at the highest-intent moment.
Campaign segmentation
Works wellSegment by purchase history, engagement, location, and custom properties. Not as deep as Klaviyo segmentation but covers the targeting options that matter for SMS.
What Does Postscript Do Well?
SMS is the only focus
Postscript does SMS and nothing else. This focus means deeper features than the SMS add-ons in Klaviyo or Omnisend. If SMS is a real revenue channel for you, the specialist tool outperforms the generalist.
Infinity Testing finds what works
Testing thousands of message variants automatically removes the manual A/B testing grind. The AI converges on high-converting copy, timing, and offers without you touching it.
Shopify integration is airtight
Because Postscript only supports Shopify, the integration is deeper and more reliable than multi-platform tools that treat Shopify as one of many connections.
Free Starter plan lowers the barrier
No platform fee on Starter - you only pay for messages sent. Makes it easy to test whether SMS works for your store before committing to a monthly subscription.
Where Does Postscript Fall Short?
Shopify only
No WooCommerce, no BigCommerce, no custom stores. If you are not on Shopify, Postscript is not an option.
US and Canada only
SMS delivery is limited to US and Canadian numbers. International sellers or stores with global customers cannot use Postscript for SMS.
Per-message costs add up
The platform fee is just the start. Message costs ($0.007-$0.015 per SMS plus carrier fees) mean a 10,000-message campaign costs $70-$150 on top of your plan fee.
Revenue attribution can overcount
Like most SMS tools, Postscript attributes revenue to messages that may not have directly driven the purchase. The numbers look impressive but take the attribution with a grain of salt.
Who Should Use Postscript?
Shopify stores where SMS is a top revenue channel
If SMS drives meaningful revenue, Postscript AI testing and conversational features give it an edge over the SMS bolt-ons in email tools.
US-based DTC brands
SMS works best for DTC brands with engaged audiences in the US. The opt-in rates and conversion rates are highest in this segment.
Stores already using Klaviyo for email
Run email through Klaviyo, SMS through Postscript. The specialist tools for each channel outperform one platform trying to do both.
Who Should Avoid Postscript?
Non-Shopify stores
Shopify only. Full stop.
International sellers
US and Canada SMS delivery only. If your customers are elsewhere, Postscript cannot reach them.
Stores not ready to invest in SMS
Even the free plan requires $49/month minimum message spend. SMS is not free to test. Make sure you have an audience before starting.
How Does Postscript Compare to Alternatives?
| Postscript | Klaviyo | |
|---|---|---|
| Starting price | Free | Free |
| Ease of use | 8/10 | 7/10 |
| Value | 8/10 | 8/10 |
| Amazon | 0/10 | 2/10 |
| Shopify | 10/10 | 10/10 |
| Overall | 7.5/10 | 8/10 |
| Best for | Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email | Klaviyo bundles email and SMS in one platform. Postscript does SMS only but deeper - Infinity Testing, conversational AI, better SMS-specific features. Use Klaviyo for email, Postscript for SMS, or Klaviyo for both if simplicity matters more. |
Sources and Further Reading
- Postscript Pricing-- Postscript
- Postscript Reviews on G2-- G2
- Postscript Shopify App Store-- Shopify App Store
What Platforms Does Postscript Support?
Frequently asked questions
Ready to try Postscript?
Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email
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