Softwr

Email Marketing · head to head

Klaviyo vs Sailthru

Klaviyo logo

Klaviyo

Email Marketing

The email and SMS marketing platform for ecommerce

From
Free
Rated
-
Full reviewWebsite
Sailthru logo

Sailthru

Email Marketing

Retail and publisher email personalisation, now one product inside the Marigold portfolio

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Klaviyo has a free tier, so it costs nothing to try first.
  • Each has a real cost: Klaviyo the free plan caps active profiles at 250 and sends at 500 emails a month; Sailthru the product sits in a portfolio with several overlapping platforms under one owner, so roadmap investment is a portfolio decision rather than a product decision and is worth asking about in writing.
  • They diverge on capability: Klaviyo covers Email marketing, Sailthru covers Interest profiles.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Klaviyo and Sailthru actually diverge.

Attributes where Klaviyo and Sailthru differ
AttributeKlaviyoSailthru
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
PlatformsWebWeb, REST API
Founded2012Unknown

Identical on both: user rating (Not yet rated), category (Email Marketing).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Klaviyo

  • Email marketing
  • SMS marketing
  • Push notifications
  • Marketing automation
  • Segmentation
  • A/B testing
  • Reporting & analytics
  • Ecommerce integrations

Only in Sailthru

  • Interest profiles
  • Personalisation engine
  • Prediction Manager
  • Site personalisation
  • Zephyr templating
  • Lifecycle optimiser

What people use each for

The jobs each tool is most often brought in to do.

Klaviyo

  • Email and SMS marketing automation for ecommerce storesnot Sailthru
  • Segmenting customers on purchase and behaviour datanot Sailthru

Sailthru

  • A publisher sending a personalised daily newsletter assembled per reader from a content cataloguenot Klaviyo
  • A retailer that wants email and on-site recommendations driven by the same affinity modelnot Klaviyo
  • High-cadence sending where per-recipient content assembly matters more than journey branchingnot Klaviyo
  • Teams that want churn and lifetime value scores available as native campaign conditions rather than imported fieldsnot Klaviyo

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Klaviyo

  • The free plan caps active profiles at 250 and sends at 500 emails a month
  • Pricing scales with stored profile count rather than with messages sent, so an unengaged list costs the same as an active one
  • SMS is metered separately, with only $5 of mobile messages included on the free plan
  • Paid tier prices are not published on the pricing page and depend on profile count

Sailthru

  • The product sits in a portfolio with several overlapping platforms under one owner, so roadmap investment is a portfolio decision rather than a product decision and is worth asking about in writing.
  • Pricing counts stored profiles, so retained inactive readers keep costing money long after they stopped opening anything.
  • On-site personalisation requires a developer to implement the JavaScript and maintain the content feed, which puts the highest-value feature behind engineering time.
  • Zephyr is a proprietary templating language, so template maintenance skills are scarce compared with the Liquid syntax used by most competitors.
  • It is built for high-cadence content and retail sending, and B2B lifecycle programmes with long sales cycles sit poorly on the model.

Pricing, plan by plan

Klaviyo

Free
  • FreeFree
    • Up to 500 contacts
    • Unlimited campaigns
    • Basic automation
  • Pro$20/month
    • Unlimited contacts
    • SMS campaigns
    • Advanced automation

Sailthru

On request
  • Sailthru$undefined/year
    • Priced on stored profiles and send volume
    • Site personalisation and prediction features licensed by module
    • Annual contract through Marigold

Which should you pick?

Choose Klaviyo if

  • You need email marketing.
  • You want to start without paying.
  • You also want sms marketing.
Klaviyo review

Choose Sailthru if

  • You need interest profiles.
  • You work on Web, REST API.
  • You also want personalisation engine.
Sailthru review

Questions people ask

Is Klaviyo or Sailthru better?
Neither clearly leads. Klaviyo starts at Free and Sailthru at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Klaviyo or Sailthru?
Klaviyo has a free tier; the other does not. Paid plans start at Free for Klaviyo and On request for Sailthru.
Does Klaviyo or Sailthru run on more platforms?
Klaviyo runs on Web. Sailthru runs on Web, REST API.
Can I use Klaviyo for free?
Yes. Klaviyo has a free tier, so you can try it without paying. Sailthru starts at On request.
What is Klaviyo best used for?
Klaviyo is most often used for email and sms marketing automation for ecommerce stores, segmenting customers on purchase and behaviour data. Of those, email and sms marketing automation for ecommerce stores and segmenting customers on purchase and behaviour data are not what Sailthru is typically brought in for.
What can Klaviyo do that Sailthru cannot?
Klaviyo covers Email marketing, SMS marketing, Push notifications, Marketing automation. Sailthru covers Interest profiles, Personalisation engine, Prediction Manager, Site personalisation.

Answered from the vendors’ own pages

Klaviyo: Is Klaviyo free?

Klaviyo has a free tier covering up to 250 active profiles, 500 email sends per month and $5 of mobile messages per month, with 10,000 Composer credits. Email support on the free tier lasts only the first 60 days.

Source
Sailthru: Who owns Sailthru now?

Marigold, formerly CM Group, which also owns Campaign Monitor, Emma, Selligent, Liveclicker and Cheetah Digital.

Klaviyo: How much does Klaviyo cost?

Klaviyo does not publish a paid rate card on its pricing page. Paid tiers are priced by active profile count and message volume, and a figure is produced through the plan estimator rather than shown as a list price.

Source
Sailthru: Does that affect the roadmap?

It can. Overlapping products in one portfolio compete for investment, so ask which platform is the strategic one for your segment before signing multi-year.

Klaviyo: What counts as an active profile in Klaviyo?

Klaviyo defines active profiles as the contacts eligible to receive marketing, and the free tier is limited to 250 of them. Profile count is the main input to what a paid plan costs.

Source
Sailthru: Is it worth it just for newsletters?

For personalised daily newsletters at publisher scale it remains one of the strongest options. For simple broadcast sending it is heavily over-specified.

Share

Related pages

More on Klaviyo

More on Sailthru

Keep looking

Other head to heads