Klaviyo vs Postscript (2026): Which Is Better for SMS?
Klaviyo SMS vs Postscript in 2026: what 1,000 to 10,000 US texts cost on each (checked 10 October), features, pros and cons, and when a second platform pays.
Table of contents
- Klaviyo vs Postscript at a glance
- Postscript is built for Shopify; Klaviyo for ecommerce generally
- Klaviyo vs Postscript pricing (October 2026)
- Where Postscript wins
- Where Klaviyo wins
- Pros and cons
- Klaviyo SMS pros
- Klaviyo SMS cons
- Postscript pros
- Postscript cons
- When to choose Postscript
- When to choose Klaviyo for both
- Klaviyo questions SMS buyers ask
- What are the weaknesses of Klaviyo?
- Why is Klaviyo so expensive?
- Who is Klaviyo’s biggest competitor?
- Migration either direction
- Practical recommendation
- Sources
Klaviyo is the better choice for most ecommerce brands: email and SMS share one profile, one flow builder and one report, and it works on any store platform. Postscript is the better choice for Shopify brands where SMS is the main retention channel and two-way, conversational texting is worth running a second platform for.
Per text, the two cost about the same. The real cost difference is operational: a Klaviyo email plus Postscript SMS stack means two databases, two sets of flows and two attribution models that rarely agree. Every price below was checked on both vendors’ pricing pages on 10 October 2026.
A note on where we stand: we’re a Klaviyo partner agency and our SMS marketing service builds on Klaviyo SMS. We still recommend Postscript when the case for it is real, and this page says when.
Klaviyo vs Postscript at a glance
| Klaviyo SMS | Postscript | |
|---|---|---|
| What it is | SMS inside an email and SMS platform | SMS specialist (with RCS) for Shopify brands |
| Store platforms | Shopify, WooCommerce, BigCommerce, Magento and custom | Shopify natively; other platforms through an SDK in your own store code |
| How you pay | Monthly messaging plan on top of an email plan | Platform fee ($0 to $500) plus per-message rates and carrier fees |
| 10,000 US texts a month | $125, carrier fees included | About $123 on Starter, $213 on Growth |
| Minimum | Any paid email plan; free plan includes $5 of messages | $49 monthly minimum spend on Starter |
| Same platform, same profile | None; pair it with an email platform | |
| Cross-channel flows | One flow can switch between email and SMS | SMS only; cross-channel needs triggers between two platforms |
| Two-way texting | Supported, less polished | A core strength: conversational selling and support |
| Short code | Separate monthly fee | $750 a month through the carriers |
| Best fit | Brands where email leads and SMS supports it | Shopify brands where SMS is the main retention channel |
USD, as of 10 October 2026. Postscript totals are our estimates from its published rates.
Postscript is built for Shopify; Klaviyo for ecommerce generally
Postscript is one of the most Shopify-integrated SMS platforms on the market. It reads Shopify customer, order and product data, and for a Shopify-only brand that wants SMS to feel like part of Shopify, it’s a strong option.
Klaviyo SMS works the same way on Shopify, BigCommerce, WooCommerce and custom integrations. Its Shopify integration is deep, and the same order and browsing events that drive your emails drive your texts. What Postscript adds on top is SMS specialism: tooling, support and service focused only on texting.
Klaviyo vs Postscript pricing (October 2026)
Klaviyo sells a monthly mobile messaging plan sized to your volume, priced per message by country, with carrier fees built in. Postscript charges a platform fee by tier plus per-message rates, with carrier fees passed through on top. In a Klaviyo email plus Postscript SMS stack you pay for Klaviyo email either way, so the comparison is the SMS line.
Monthly cost of US SMS in USD, as of 10 October 2026:
| US texts a month | Klaviyo SMS (toll-free) | Postscript Starter | Postscript Growth |
|---|---|---|---|
| 1,000 | $15 | ~$52 | ~$111 |
| 5,000 | $70 | ~$66 | ~$157 |
| 10,000 | $125 | ~$123 | ~$213 |
How we built the Postscript columns: Starter is $0 a month with a $49 minimum spend and $0.009 per SMS. Growth is $100 a month and $0.008 per SMS. Professional is $500 a month and $0.007 per SMS. To each we added Postscript’s listed US carrier fee of $0.0033 per SMS, and where Starter’s message charges fall under the $49 minimum we used the minimum. Klaviyo’s figures are plan prices from its calculator with carrier fees included.
What the table doesn’t show:
- MMS. Postscript charges $0.045 per MMS on Starter, $0.03 on Growth and $0.024 on Professional, plus $0.00799 in US carrier fees. Klaviyo’s calculator puts 1,000 US toll-free MMS at $45 a month.
- Extras. Postscript’s AI Plan is $699 a month with per-message rates of $0.003 to $0.30 depending on product and message type. A dedicated short code is $750 a month through the carriers on Postscript; Klaviyo bills short codes separately from the messaging plan.
- Trial. Postscript’s free trial gives a $100 credit for the first 30 days. Klaviyo’s free plan includes $5 of mobile messages a month.
- Rollover. Klaviyo’s unused messaging spend doesn’t roll over, so size the plan to real volume. Full detail is in our Klaviyo SMS pricing and Postscript pricing guides.
So per text it’s close. Klaviyo is far cheaper at 1,000 texts because of Postscript’s $49 minimum; from about 5,000 texts Postscript Starter is level or a few dollars cheaper. The difference you’ll feel is running one platform or two.
Where Postscript wins
Shopify-native depth. Postscript is built around Shopify customer, order and product data. For Shopify-only brands obsessed with SMS performance, that focus shows.
SMS specialism. Subscriber acquisition tools, opt-in keywords and support from a company that only does SMS. Higher tiers add enhanced analytics, API access and, on Enterprise, a dedicated customer success manager.
Conversational commerce. Postscript’s two-way SMS for customer service, cart recovery and personal shopping conversations is more polished than Klaviyo’s two-way handling.
RCS. Postscript sells SMS and RCS together on its pricing page, with RCS as an option on Enterprise.
Where Klaviyo wins
One profile. Email and SMS consent live on the same Klaviyo profile, with the full cross-channel history in one place. With Postscript SMS and Klaviyo email, you maintain two databases that need syncing.
Cross-channel flows. A Klaviyo flow can include email and SMS steps with branch logic: if the email isn’t opened, send the text. Postscript flows are SMS only, so cross-channel orchestration means triggering between two platforms.
One attribution model. Klaviyo reports email and SMS revenue with the same attribution windows. Two-platform stacks need reconciling, and the two dashboards often both claim the same order.
Any store platform. BigCommerce, WooCommerce or custom, Klaviyo email and SMS work the same. Postscript needs its SDK added to your store code.
Carrier fees included. Klaviyo’s plan price includes them. Postscript adds them on top.
Pros and cons
Klaviyo SMS pros
- Email and SMS on one profile, in one flow builder, with one attribution model
- Works on Shopify, WooCommerce, BigCommerce, Magento and custom stores
- Carrier fees included in the plan price
- Cheapest of the two at low volume, with no monthly minimum beyond your email plan
Klaviyo SMS cons
- Two-way conversational texting is less polished than Postscript’s
- Unused messaging spend expires each month
- CBD and cannabis are prohibited on SMS and MMS in the US and Canada
- Less SMS-specific service and support
Postscript pros
- SMS specialist with Shopify-native data
- Strong two-way and conversational texting
- Published, simple per-message rates with a $0 entry platform fee
- SMS-focused support, with a dedicated manager on Enterprise
Postscript cons
- No email: you run a second platform and sync it
- Shopify-first; other platforms need development work
- Carrier fees and a $49 minimum on top of per-message rates
- Two attribution models to reconcile
When to choose Postscript
- Shopify-only and SMS is your dominant channel. If SMS carries more of your retention revenue than email and you’re 100% Shopify, Postscript’s focus can justify a second platform.
- Your email runs well on Klaviyo and you want specialist SMS. Adding Postscript to a healthy Klaviyo email program is a common upgrade.
- Conversational SMS is core to your customer experience. Personal shopping, two-way support and conversational selling are where Postscript is genuinely better.
When to choose Klaviyo for both
For most ecommerce brands, unified Klaviyo email and SMS is the better answer:
- One platform, one profile, one report
- Cross-channel flows without syncing two systems
- Comparable per-text cost, with carrier fees included
- Klaviyo SMS covers the abandoned cart, post-purchase, back-in-stock and campaign texts most stores actually send
The brands that benefit most from consolidating are the smaller ones running Klaviyo email plus Postscript SMS where SMS isn’t their main channel. They added Postscript hoping for an SMS lift, found it modest, and now carry two-platform overhead for little benefit.
Klaviyo questions SMS buyers ask
What are the weaknesses of Klaviyo?
For an SMS buyer, three matter. Two-way texting is less polished than a specialist’s, so conversational selling is better on Postscript. Messaging is billed per message on a monthly plan, and unused spend doesn’t roll over. And some categories can’t text at all: CBD and cannabis are prohibited on SMS and MMS in the US and Canada, and prescription products on every channel. Our Klaviyo review covers the full list and the workarounds.
Why is Klaviyo so expensive?
The SMS line isn’t the expensive part: $125 for 10,000 US texts is level with Postscript Starter. The email plan is, because Klaviyo bills every profile you can email, and since February 2025 your plan must cover that full count. Suppress profiles that never engage and the bill drops a tier, and size your SMS plan to real volume so you don’t pay for texts you never send. Our Klaviyo pricing guide has the tier table.
Who is Klaviyo’s biggest competitor?
For SMS, Attentive and Postscript: Attentive at enterprise scale on quoted pricing, Postscript for Shopify brands on published rates. For email it’s Omnisend and Mailchimp for small stores, and Braze and Iterable at enterprise scale. Our Klaviyo alternatives guide compares twelve, Klaviyo vs Attentive covers the other SMS specialist, and our best SMS marketing platforms guide ranks the full SMS shortlist by use case.
Migration either direction
Postscript to Klaviyo SMS: subscriber records move with their consent preserved, sending numbers are replaced or migrated, and flows are rebuilt in Klaviyo. Two to four weeks for most brands.
Klaviyo SMS to Postscript: the same constraints in reverse. Email stays in Klaviyo; only SMS moves.
Practical recommendation
Shopify brands at $1M to $10M with email-led retention: Klaviyo for both. One profile and lower complexity outweigh Postscript’s Shopify depth at this scale.
Shopify brands at $10M+ with heavy SMS investment: Klaviyo email plus Postscript SMS is reasonable. The depth and the SMS spend justify the extra platform.
Non-Shopify brands at any scale: Klaviyo for both. Postscript’s route for other platforms needs development work.
Want to know whether your current SMS setup fits your scale? Book a free audit. We’ll tell you when Postscript wins and when consolidating to Klaviyo SMS is the better answer, and our Klaviyo agency team handles the build either way.
Sources
- Postscript Pricing: tiers, per-message rates, carrier fees, short code, AI Plan, trial and SDK (10 October 2026)
- Postscript + Klaviyo
- Klaviyo Pricing: mobile messaging calculator (1 and 10 October 2026)
- Klaviyo Help Center, Understand Klaviyo’s mobile messaging system: carrier fees, rollover
- Klaviyo, Acceptable Use Policy (updated 9 April 2026)
/ Frequently Asked Questions
Q.01 What's better, Klaviyo SMS or Postscript? +
/ Answer
For most ecommerce brands, Klaviyo SMS, because texts share one profile, one flow builder and one attribution model with your email, and it works on any store platform. Postscript is the specialist: built around Shopify, stronger on two-way conversational texting, and focused only on SMS. It earns its place when SMS is your main retention channel on a Shopify-only store.
Q.02 How much does SMS cost on Klaviyo compared with Postscript? +
/ Answer
As of 10 October 2026, Klaviyo's US toll-free SMS plan is $15 a month for 1,000 texts, $70 for 5,000 and $125 for 10,000, carrier fees included, on top of your email plan. Postscript Starter has no platform fee but a $49 monthly minimum, with texts at $0.009 plus a listed US carrier fee of $0.0033, so 10,000 texts come to about $123. Growth adds a $100 platform fee for lower rates. Per text, the two are close; the bigger cost difference is running two platforms.
Q.03 Does Klaviyo SMS include carrier fees? +
/ Answer
Yes. Klaviyo's mobile messaging plan price includes carrier fees, and its help centre says they never appear as separate invoice lines. Postscript charges carrier fees on top of its per-message rates: $0.0033 per US SMS and $0.00799 per US MMS, as listed on its pricing page on 10 October 2026.
Q.04 Can I use Postscript together with Klaviyo? +
/ Answer
Yes, and it is a common stack: Klaviyo for email, Postscript for SMS, connected through Postscript's Klaviyo integration. It works, but you maintain two profile databases, two sets of flows and two attribution models, which is the overhead that consolidating onto Klaviyo email and SMS removes.
Q.05 Does Postscript work with BigCommerce or WooCommerce? +
/ Answer
Not natively. Postscript is built around Shopify and its data. As of 10 October 2026, its pricing page says merchants on other platforms can add Postscript's SDK to their own store code, which means development work and less data depth. On BigCommerce, WooCommerce or a custom platform, Klaviyo SMS is usually the practical choice.
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