Customer.io vs Klaviyo: which costs less as your list grows?
Email marketing and CRM platforms · Verified · By Joonas Rotko
Customer.io
Desk research
From Essentials, billed monthly
$100/mo
Klaviyo
Desk research
From Marketing, billed monthly
$20/mo
vs
Quick answer
Klaviyo is cheaper for a small list, and the two are level at 5,000 profiles. At 500 profiles Klaviyo is $20/month billed monthly and Customer.io is $100/month billed monthly. At 5,000 profiles both are $100/month billed monthly. Both are monthly prices, and Klaviyo's free plan covers 250 profiles. Both tools lean technical, more agency and product-team territory than a typical small-business newsletter pick. Prices as of 1 Oct 2026.
Across the three setups below: Customer.io in 2 of 3 scenarios.
Which one fits you?
Solo marketer or small business, a list just past the free tier
Klaviyo
My pick
$20/mobilled monthly
At 500 profiles Klaviyo's Marketing plan is $20/month billed monthly and Customer.io's Essentials is $100/month billed monthly, both monthly. Customer.io's entry price covers up to 30,000 profiles, so a small list pays for room it doesn't use. Under 250 profiles Klaviyo's free plan costs nothing.
Why this pick, and when to skip it
Skip it if you're building event-driven product messaging and want SMS, push, in-app and WhatsApp on the entry plan. Customer.io includes those on Essentials, while Klaviyo sells SMS usage separately.
At 5,000 profiles the monthly prices are level: Customer.io is $100/month billed monthly and Klaviyo is $100/month billed monthly. Just above this size Klaviyo's published bands are a little lower, and Customer.io's ladder is lower once a list reaches the tens of thousands. Customer.io also states unlimited seats and puts SMS, push, in-app and WhatsApp on the same plan.
Why this pick, and when to skip it
The two monthly prices match at this size, so I decided on the published seat count and the channels included in the entry plan.
Skip it if you run an online store and want Klaviyo's ecommerce segmentation and its Composer and Customer Agent AI tools. Those are priced separately from the email plan.
Three seats cost nothing extra on Customer.io, whose Essentials seat allowance is stated outright: Unlimited. A 1,000-profile team is $100/month billed monthly. Klaviyo publishes no seat count for its Marketing plan, so a 3-person team can't be priced there.
Why this pick, and when to skip it
Only Customer.io confirms the seat count, so this pick rests on seats and not on list price.
Skip it if you can confirm Klaviyo's login count with the vendor and want the lowest list price. Klaviyo's published monthly price at a 1,000-profile list is below Customer.io's flat entry rate.
Essentials is a monthly ladder that starts at $100/month billed monthly and runs up to 30,000 profiles. Premium starts at $1,000/month billed annually, annual billing, but that's a floor set behind a demo call, not a checkout page.
Klaviyo
The Marketing plan (email) starts at $20/month billed monthly for 500 active profiles and rises in bands up to 150,000 profiles. Monthly only, with no annual rate.
Klaviyo's price is lower below 5,000 profiles, the two are level at 5,000 and stay close to 10,000, and Customer.io's published monthly ladder is lower once a list reaches the tens of thousands.
Free plan vs trial
Customer.io
None. A 14-day trial capped at 5,000 messages across channels, then no free plan at all
Klaviyo
Permanent: 250 profiles, 500 emails a month, $0/month billed monthly
Only Klaviyo lets you run real campaigns indefinitely without paying, but its free ceiling is tight next to a real contact list.
Channel breadth on the entry tier
Customer.io
SMS, push, in-app and native WhatsApp all ship on Essentials alongside email, with unlimited push, in-app and webhook volume
Klaviyo
Email is in the Marketing plan. SMS and other mobile messages, social marketing and reviews are priced on top of it.
Customer.io puts its channels in the entry plan. On Klaviyo each extra channel adds to the email price.
Refund terms
Customer.io
No money-back guarantee. The terms of service state fees are non-refundable outside of legal requirements
Klaviyo
No refund policy is stated on Klaviyo's pricing page
Customer.io states a definitive no on refunds. Klaviyo's pricing page says nothing either way.
What will Customer.io or Klaviyo cost for your setup?
The cheapest plan that covers each setup, add-ons included. Prices exclude VAT.
Solo marketer or small business, a list just past the free tier
500 subscribers · mailed 3 times a month (for tools priced by emails sent) · 1 user
ToolMonthlyYearly, per month
Customer.io
$100
Monthly only
Essentials
Above 30,000 subscribers: nothing published fits.
Klaviyo
My pick
$20
Monthly only
Marketing
Above 150,000 subscribers: nothing published fits.
The plan's price is published, but a limit this setup needs isn't, so the fit can't be confirmed.
How I calculated this
For each tool I price every current plan plus the add-ons a setup needs, from the vendor's published prices only, and take the cheapest. Monthly and annual billing are priced separately. When a limit or price isn't published, the tool shows as not fitting instead of a guess.
Solo marketer or small business, a list just past the free tier: A list of about 500 contacts, just past the free tiers most vendors offer. One login. Tools priced by emails sent are costed at three mailings per subscriber a month.Customer.io, annual billing: Not sold on annual billing. Price limit isn't published.Klaviyo, annual billing: Not sold on annual billing. Price limit isn't published.
Growing list, sending regularly: A list of 5,000 contacts, sending regularly. One login. Tools priced by emails sent are costed at three mailings per subscriber a month.Customer.io, annual billing: Not sold on annual billing. Price limit isn't published.Klaviyo, annual billing: Not sold on annual billing. Price limit isn't published.
Small team managing one list together: Three people logging in to the same 1,000-contact list. Seats, not list size, are the deciding limit. Tools priced by emails sent are costed at three mailings per subscriber a month.Customer.io, annual billing: Not sold on annual billing. Price limit isn't published.Klaviyo, monthly billing: Marketing is priced, but users limit isn't published. Users limit isn't published.Klaviyo, annual billing: Marketing has no published price. Users limit isn't published. Price limit isn't published.
Customer.io vs Klaviyo side by side
I compare email/CRM platforms on: Real cost per list size, both billing bases; Free-tier contact ceiling before you must pay anything; Team seats included, and the seat price past that; List segmentation depth; Automation workflow depth and any step/action limits; Deliverability and sending limits (emails per month, per day, or per rolling window); CRM and ecommerce integration depth; What happens past your plan's contact ceiling (overage pricing vs a forced upgrade).
Customer.io and Klaviyo compared on the main buying criteria
Criterion
Customer.io
Klaviyo
Real cost per list size, both billing bases
Essentials starts at $100/month billed monthly and covers up to 30,000 profiles on a monthly ladder. No annual discount is published for this tier
Free is $0/month billed monthly up to 250 profiles. The Marketing plan starts at $20/month billed monthly for 500 active profiles and rises in bands. No annual rate is published
Free-tier contact ceiling before you must pay anything
None. A 14-day trial capped at 5,000 messages across channels, then no free plan at all
250 profiles on Free, permanently, no trial clock
Team seats included, and the seat price past that
Unlimited on Essentials, Premium and Enterprise alike, no per-seat charge on any tier
The pricing page states no seat count or extra-seat price for any Klaviyo plan
List segmentation depth
Not documented by Customer.io beyond the workflow builder itself
Segmentation is a named Klaviyo feature, but its pricing page doesn't say how deep it goes
Automation workflow depth and any step/action limits
The visual workflow builder ships on every tier, including Essentials, with unlimited monthly API calls; the pricing page doesn't publish a step-count or action limit for it
No step or action limit is published for the Marketing plan
All details, including automation and AI workflows
All compared details for Customer.io and Klaviyo
Criterion
Customer.io
Klaviyo
Deliverability and sending limits (emails per month, per day, or per rolling window)
No separate monthly send cap is published for Essentials; extra volume past the plan is billed at $0.12/month per 1,000 emails
10 x active profiles (5,000 emails/month at 500 profiles, 50,000 at 5,000, 1,500,000 at 150,000). The free plan allows 500 emails a month
CRM and ecommerce integration depth
Data integrations split into 'Basic' (Essentials) and 'Basic & Premium' (Premium, Enterprise) on the pricing page, but it doesn't name which integrations (Segment, Zapier, Salesforce) sit in each bucket
Data + Analytics is a separate Klaviyo tier, priced on top of the email plan
What happens past your plan's contact ceiling (overage pricing vs a forced upgrade)
Extra profiles cost $0.01/month each on Essentials; past 30,000 profiles, Premium requires a demo call instead of a self-serve upgrade
The price steps up band by band. On the free plan you must move to Marketing past 250 profiles. Past 150,000 profiles you talk to sales
Full price list
Essentials: $100/month billed monthly for 30,000 profiles. Premium starts at $1,000/month billed annually, annual billing, behind a demo call rather than a checkout page. Enterprise publishes no floor at all.
Free: $0/month billed monthly, up to 250 profiles. Marketing (email) starts at $20/month billed monthly for 500 active profiles and runs up to 150,000 profiles, monthly billing only. Add-ons and the other tiers are priced separately.
Pricing model
Priced by profile count on a tiered ladder for Essentials; Premium and Enterprise move to negotiated, volume-based pricing with no public rate card
Klaviyo prices email by active profiles (unique people in the account) on a slider, not by a flat plan: Email is included in the Marketing solution and costs $20/month at 500 profiles up to $1,955/month at 150,000 profiles, with send limits at 10 emails per profile; above 150,000 profiles it is Talk to sales. The page shows monthly USD prices only (no annual toggle). Other add-ons (Composer, Customer Hub, Social marketing, Reviews, SMS and other mobile messages) are priced separately; Service and Customer Agent carry an introductory discount.
Trial and free plan
14-day trial capped at 5,000 messages across channels. No permanent free plan; Essentials is the cheapest published tier at $100/month billed monthly.
Free plan is permanent, not a trial: 250 profiles, 500 emails a month, $0/month billed monthly.
Refund / money-back terms
No money-back guarantee. The terms of service state fees are non-refundable outside of legal requirements.
No refund policy is stated on Klaviyo's pricing page.
Support on the entry/paid tier
Not stated on Customer.io's pricing page.
Standard support included; FAQ lists onboarding, Community, Academy, chat, growth success team, agency partners. On the free plan: Email support for first 60 days, then Help Center and community only.
Channels supported on the entry tier
SMS, push, in-app and native WhatsApp all ship on Essentials alongside email, with unlimited push, in-app and webhook volume.
Email in the Marketing plan. SMS and other mobile messages, social marketing and reviews are priced on top of it.
Workspaces
2 on Essentials, unlimited on Premium and Enterprise.
Not a concept Klaviyo's pricing page uses.
Extra seat pricing
No per-seat charge on any tier; seats are unlimited from Essentials up.
The pricing page states no seat count or extra-seat price for Klaviyo.
Who should pick Customer.io, and who should pick Klaviyo?
Customer.io
Desk research
Best for growing lists sending regularly
Best for small teams sharing one account
Customer.io only publishes one real number: $100/month billed monthly for Essentials, capped at 30,000 profiles. Everything past that is a quote, with Premium starting at $1,000/month billed annually and Enterprise not even showing a floor.
Best for: A team that has outgrown a basic email tool and needs cross-channel journeys (email, SMS, push, WhatsApp) with unlimited seats on the entry plan.
Strengths
Unlimited seats and unlimited API calls on every tier, including Essentials.
SMS, push, WhatsApp and webhooks all ship on the entry plan, not gated to a higher tier.
A 14-day trial that includes every channel, not a stripped-down preview.
Limits
No money-back guarantee. The terms of service call fees non-refundable outside of legal requirements.
Premium has no self-serve checkout, only a demo call, and its $1,000/month billed annually figure is a starting point, not a fixed price.
Enterprise publishes no price at all, just a sales conversation.
Skip it if you want a fixed monthly bill past the entry tier; Premium and Enterprise both require a sales call and a negotiated price.
Klaviyo has a free plan for up to 250 profiles and 500 email sends per month. Its Marketing (Email) plan is priced per active profile, starting at $20/month billed monthly at the smallest profile band and rising with each band up to 150,000 active profiles. Above that Klaviyo says to talk to sales. Prices are published monthly only.
Best for: Teams that want to start on the free plan and move to a published per-profile Email price as their list grows.
Strengths
Free plan for up to 250 profiles and 500 email sends per month.
Marketing (Email) pricing is published: $20/month billed monthly at the entry band, with a price for each active-profile band up to 150,000 profiles.
Limits
Prices are monthly only; the pricing page shows no annual option.
Above 150,000 active profiles the page says to talk to sales rather than showing a price.
The free plan caps at 250 profiles and 500 email sends per month.
Skip it if you want annual billing, a published price above 150,000 active profiles, or a flat price that does not rise with list size.
Pick it if you want CRM and ecommerce bundled into one plan with an annual-billing price list, instead of either Customer.io's profile-tiered Essentials or Klaviyo's add-ons.
Pick it if you're a SaaS team that wants one predictable price on a slider, every feature included even on the free plan, and no sales call at any size short of the very top band.
Neither pricing page promises an import from the other, so plan to rebuild your segments, workflows and journeys by hand in either direction. Customer.io's only free option is a 14-day trial capped at 5,000 messages across channels, so testing your real automations before committing to Essentials is tight. Klaviyo's free plan is permanent rather than a trial, so you can build out a real account up to 250 profiles before deciding whether to move further.
What would change my pick?
A list under 250 active profiles makes Klaviyo's free plan the pick, whatever the paid prices are.
A store that needs Klaviyo's ecommerce segmentation would move me to Klaviyo even at a size where the monthly prices are level.
Customer.io publishing a self-serve price for Premium, instead of a starting figure behind a demo call, would change the picture for lists past its Essentials ceiling.
A price or tier change on either side.
Customer.io vs Klaviyo: questions people ask
Is Customer.io cheaper than Klaviyo?
It depends on list size. At 500 profiles Klaviyo is $20/month billed monthly and Customer.io is $100/month billed monthly. At 5,000 profiles both are $100/month billed monthly. These are monthly prices, and Klaviyo counts active profiles.
Does Customer.io have a free plan?
No. Only a 14-day trial, capped at 5,000 messages across every channel. After that you're on Essentials or a higher paid tier.
Does Klaviyo have a free plan?
Yes, and it's permanent, not a trial: 250 profiles, 500 emails a month, $0/month billed monthly. Email support for first 60 days, then Help Center and community only.
Does Klaviyo publish its paid prices?
Yes. Email is priced per active profile in bands, from $20/month billed monthly at 500 profiles up to 150,000 profiles, monthly only. Above that it says to talk to sales. Other tiers and add-ons are priced separately.
Which tool fits an agency or a technical team better than a small-business newsletter sender?
Both, more than most tools in this category. Customer.io and Klaviyo are built for behavior-triggered, data-driven messaging (event-based journeys, ecommerce triggers, multi-channel workflows), which takes more setup than a plain newsletter tool and rewards a team with engineering or data resources. A solo small-business owner sending a weekly newsletter is usually better served by a simpler ESP; an agency or in-house product team running lifecycle campaigns across email, SMS and push is the real fit for either of these two.
Do Customer.io or Klaviyo offer a money-back guarantee?
Customer.io doesn't. Its terms of service state fees are non-refundable outside of legal requirements. Klaviyo's pricing page states no refund policy, so it's not confirmed either way.
What will this cost me at 10,000 profiles?
Customer.io's Essentials ladder runs to 30,000 profiles, so 10,000 is on the published ladder. Klaviyo's Marketing ladder covers it too. Past Essentials, Premium starts at $1,000/month billed annually behind a demo call. Compare the two ladders at your own count, since Klaviyo counts active profiles.
How I verified this
Every price and limit here comes from the vendors' own pages, last checked . Customer.io: desk research. Klaviyo: desk research.
: New page. Klaviyo is the pick for a 500-profile list. Customer.io is the pick for a 5,000-profile list, where the two monthly prices are level, and for the 1,000-profile team of three, since only Customer.io publishes a seat count. Overall pick: Customer.io. Neither tool has an affiliate link, so every link on the page is plain.
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