What the interviews show. These interviews do not establish an overall winner, and brands have moved SMS in both directions. Several moved SMS from Klaviyo to Postscript, citing limited SMS features, weak pop-ups and list growth, or wanting a specialist's support; a few moved from Postscript to Klaviyo to consolidate reporting and cut what one calls swivel-chair work. A recurring setup among Postscript buyers is Klaviyo for email and Postscript for SMS, so the decision is often whether to keep SMS in Klaviyo or add a specialist beside it. Klaviyo's SMS buyers praise having email and SMS in one place; their most frequent complaint is that SMS feels like an add-on next to a specialist, along with deliverability and compliance limits, support and cost. Postscript buyers praise its support, its SMS flows, list growth and pricing; their complaints are integration with the rest of the stack, weak segment building for some, and fees.
| Strongest contrast in these interviews | Commentary centres on email and SMS in one place, and on SMS that feels like an add-on | Commentary centres on support and SMS-specific features, as a specialist beside the email platform |
|---|---|---|
| Buyer pattern in these interviews | Mostly Shopify DTC brands, plus some multi-brand and enterprise retail groups | Shopify DTC brands, many of them running Klaviyo for email |
| Most-discussed job | SMS inside the email platform | Specialist SMS for Shopify brands |
| Also does | Email and customer data in the same platform | AI-driven message flows and a managed service, for some buyers |
| Praised most | Email and SMS in one place — shared segments and email and SMS under one roof | Support, SMS flows, list growth and pricing |
| Top complaint | SMS that feels like an add-on next to a specialist; deliverability and compliance limits; support; cost | Integration with the rest of the stack; weak segment building for some; fees |
| Relative cost | Contested: cheap for some on SMS, expensive for others | Often called cheaper than Attentive; some describe hidden fees, minimums and costs at scale |
| Where buyers say it fits | Includes brands consolidating email and SMS, several arriving from Attentive | Includes brands adding a specialist SMS layer beside Klaviyo email |
What buyers say about each platform
Every buyer interview spends its minutes somewhere — praising the thing that won the deal, or flagging the thing that still stings. Map where those minutes go for Klaviyo's SMS and Postscript, and the two sort less by what they do than by where buyers' praise and complaints concentrate:
Relative share of buyer commentary by theme in Alium's verified interviews, praise vs. complaint, through October 2026. Widths compare themes within this pair — they are relative, not counts. Klaviyo's SMS is discussed by more buyers, so each side is scaled to that vendor's own buyers.
In their own words
The phrases buyers reach for, verbatim, when they describe each platform:
Klaviyo
“We like the interplay of email and SMS having both under one roof.” one platform
“it was very easy to kind of use that same segment for SMS” segments
“we get cost savings from having both email and SMS through Klaviyo” cost
“SMS to me has been a little bit of an afterthought for them” SMS depth
“Their capabilities on SMS are very, very bare-bones” features
“It's a one way text system.” two-way texting
Postscript
“Customer support is unbelievable.” support
“They come to the table with a lot of recommendations” strategy
“We've actually been able to grow our list more quickly” list growth
“segment building is pretty weak in the platform” segmentation
“A lot of hidden fees” fees
“They're fantastic at SMS, but it's all they do.” one more tool
Where Klaviyo buyers concentrate their praise
Klaviyo's SMS buyers concentrate their praise on having email and SMS in one place. “We like the interplay of email and SMS having both under one roof,” says one; another found “it was very easy to kind of use that same segment for SMS,” and another says “we get cost savings from having both email and SMS through Klaviyo.” The most frequent complaint is that SMS feels secondary next to a specialist — “SMS to me has been a little bit of an afterthought for them,” says one, and another calls its capabilities “very, very bare-bones.” Buyers also describe deliverability and compliance limits, including category restrictions and weak pop-ups for list growth, support some find slow, and SMS costs that are cheap for some and expensive for others. Some say the SMS product has improved over time.
Where Postscript buyers concentrate their praise
Postscript buyers concentrate their praise on support — “Customer support is unbelievable,” says one — and on its SMS flows, list growth and pricing: one says “They come to the table with a lot of recommendations,” another that “We've actually been able to grow our list more quickly.” The complaints center on fitting it into the rest of the stack: one brand that later moved SMS to Klaviyo says “They're fantastic at SMS, but it's all they do.” Some find “segment building is pretty weak in the platform,” and some describe fees — “A lot of hidden fees,” says another. A few describe it as a younger product than its larger rivals.
On cost, buyers disagree. One brand says “I use Postscript for SMS because pricing is better over there,” while another stays on Klaviyo SMS “because they gave us such a cheap price on SMS”; a third calls the two comparable. Both are often described as cheaper than Attentive.
What buyers wish they'd known
Before picking Klaviyo
The most frequent complaint is that SMS feels like an add-on to an email platform, with thinner flows and features than a specialist — no two-way texting, for one. Buyers also describe deliverability and compliance limits, including category restrictions and weak pop-ups for list growth, support some find slow, and SMS costs some call expensive. One brand that consolidated SMS onto Klaviyo saw subscribers drop and went back to a specialist.
Before picking Postscript
Buyers describe running it as a separate tool beside the rest of the stack, with integration some find weak, segment building and reporting some find thin, and fees — hidden fees, minimum spends and costs that climb at scale. A few call it a younger product, and one found its automated flows sent more than it wanted.
Four questions the interviews raise
Many buyers call its SMS an add-on next to a specialist; others are satisfied with it as part of the platform.
Buyers praise its SMS-specific flows and list-growth capabilities.
Buyers praise shared segments and having email and SMS under one roof across email and SMS.
Many run it beside Klaviyo email; some find the separate tool and its integration a burden.
Support draws more complaint than praise, and one buyer notes there is no managed service.
Support is its most-praised theme, and some use its managed service.
Cheap for some, expensive for others; one buyer says prepaid credits it does not use are lost.
Often called cheaper than Attentive; some describe hidden fees, minimums and costs at scale.
How the operating conditions differ
Recurring situations in the corpus, and where the evidence concentrates in each:
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Get the read for your brand →Pressures visible in these interviews
The complaints these interviews carry sit on both sides: Klaviyo's are SMS that feels like an add-on, deliverability and compliance limits, support and cost; Postscript's are integration with the rest of the stack, weak segment building for some, and fees. The clearest distinction in these interviews is where buyer emphasis falls: Klaviyo's SMS buyers talk more about having email and SMS in one place, while Postscript buyers talk more about support and the SMS program itself. Brands move both ways on exactly that line — one that consolidated onto Klaviyo describes “a lot of benefits come to fruition with the reduction in swivel chair,” while one that stayed with Postscript says “We purposefully don't use Klaviyo SMS.” One way to read that — ours rather than a rule buyers state — is that the question is less which SMS product is stronger than whether a specialist's support and SMS features are worth running a second tool beside Klaviyo email. For the category as a whole, see what SMS buyers wish they'd known and what buyers actually pay for SMS; for each against Attentive, Klaviyo vs. Attentive and Attentive vs. Postscript.
Common questions
Klaviyo vs. Postscript: which is better?
These interviews do not establish an overall winner, and brands have moved SMS in both directions. Klaviyo's SMS buyers praise having email and SMS in one place, though many call its SMS an add-on next to a specialist. Postscript buyers praise its support, its SMS flows and list growth, though some find running a separate tool a burden. A recurring setup is both: Klaviyo for email and Postscript for SMS.
Should I use Klaviyo for email and Postscript for SMS?
Many Postscript buyers in these interviews run exactly that setup. They praise Postscript's SMS-specific support and features while keeping Klaviyo for email, and one says it purposefully does not use Klaviyo SMS. Some brands later consolidate SMS into Klaviyo to reduce reporting and workflow fragmentation.
Is Klaviyo SMS as good as Postscript?
Many buyers in these interviews say Klaviyo's SMS feels like an add-on to an email platform, with thinner features than a specialist. Others are satisfied with it as part of one platform, and some say it has improved over time.
Is Postscript cheaper than Klaviyo SMS?
Buyers disagree. One brand uses Postscript because its pricing is better, another stays on Klaviyo SMS because of the price it was offered, and a third calls the two comparable. Both are often described as cheaper than Attentive, and some Postscript buyers describe hidden fees, minimums and costs that climb at scale.
Why do brands move SMS from Klaviyo to Postscript?
Brands that moved describe Klaviyo's SMS features as limited, weak pop-ups and list growth, and wanting the support or managed service a specialist provides. The move also runs the other way: brands that consolidated SMS onto Klaviyo describe simpler reporting and less work switching between tools.
See which one fits your exact stack
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