Mailchimp vs Klaviyo: equal at 500 and 5,000, apart at 10,000 and 25,000
Klaviyo prices its email plan by active profiles: $20 at 500, $100 at 5,000, $150 at 10,000 and $400 at 25,000. Mailchimp Standard reads $20 at 500, $100 for 2,501 to 5,000, $135 for 5,001 to 10,000 and $310 for 20,001 to 25,000. The curves match at the small sizes and part by $15 and then $90 a month. Which one you want depends mostly on events: both can take them over an API, but they differ on duplicates, plan gating and how long event data lasts.
By Julian Pryor · Updated 7 Oct 2026
Short answer
Choose Klaviyo when events and revenue are the core of your email program and your list is under 5,000, where it costs the same as Mailchimp and handles event duplicates and bulk loads more explicitly. Choose Mailchimp when your list is 10,000 or more and the bill matters, when you can use its first-year discounts, or when you want audiences, custom-coded templates and SMS from one familiar vendor.
Same price at two sizes, different at two
Klaviyo's numbers are the email-plan readouts from the profile selector on klaviyo.com/pricing. Mailchimp's are Standard-plan band quotes from mailchimp.com/pricing/marketing. Both were read on 7 October 2026 on monthly billing.
| Contacts or profiles | Klaviyo email plan | Mailchimp Standard | Difference |
|---|---|---|---|
| 500 | $20 | $20 | None |
| 1,000 | $30 | No readout | |
| 2,500 | $60 | No readout (band 2,501 to 5,000 is $100) | |
| 5,000 | $100 | $100 | None |
| 10,000 | $150 | $135 | Klaviyo $15 more |
| 25,000 | $400 | $310 | Klaviyo $90 more |
Over a year that is $180 at 10,000 and $1,080 at 25,000. Mailchimp's first-year offers on the same page widen the gap while they last: $50 for the 2,501 to 5,000 band, $67.50 for 5,001 to 10,000 and $155 for 20,001 to 25,000, which would put Klaviyo $50, $82.50 and $245 a month higher in year one. Klaviyo's page shows no equivalent introductory discount.
What the same money sends
Klaviyo's selector pairs each profile count with a send allowance of ten times the profiles: 50,000 emails at 5,000 profiles, 100,000 at 10,000, 250,000 at 25,000. Mailchimp Standard's allowance is 12 times the contacts in the band, 60,000 at the 2,501 to 5,000 band and 120,000 at 5,001 to 10,000. At the same list size that is twelve sends per contact on Mailchimp against ten on Klaviyo, which matters if you mail a small list often and not at all if you mail it weekly.
Klaviyo describes an active profile as a contact who may receive marketing email, which is a looser unit than a plain contact count. Mailchimp bills overages automatically after the trial and keeps campaigns running while you pay.
Free plans are twins
Klaviyo's free plan: up to 250 active profiles, 500 emails a month, $5 of mobile messages, $5 of Composer usage, built-in reporting, web forms and email support for the first 60 days. Mailchimp's free plan: 1 seat, 1 audience of up to 250 contacts, 500 sends a month with 250 a day at most. A 250-person early beta list fits either; a 300-person list fits neither.
Event APIs side by side
| Behavior | Klaviyo Events API | Mailchimp Events endpoint |
|---|---|---|
| What you send | A metric name plus at least one profile identifier, with properties (up to 400) and an optional value | An event name and properties for a list member |
| Contact must exist first | The profile identifier travels with the event | Yes: contacts must already be in your audience |
| Duplicate protection | unique_id idempotency key per profile and metric | None described in the docs read |
| Bulk loading | Up to 1,000 events per request | Not described |
| Loading history without triggering sends | backfill: true | is_syncing: true with occurred_at |
| Starting a flow | Custom events can trigger flows | Paid plans; single-step on Essentials, multi-step from Standard |
| How long event data is usable for segments | Not stated on the page read | 30 days on Free and Essentials, 3 months on Standard, 18 months on Premium |
Klaviyo's reference also warns that a 202 response does not guarantee an event was kept, that test-domain addresses are silently dropped, and that two same-second events for one profile and metric can collide without a unique_id. Both are documented at Klaviyo's Events API overview and Mailchimp's events guide.
A failed payment, step by step
Stripe retries a webhook delivery for up to three days if your endpoint fails, so the same invoice.payment_failed can arrive twice. With Klaviyo, send the Stripe event ID as unique_id and the flow fires once. With Mailchimp, store the event ID in your own database and skip repeats before posting, because the endpoint documentation read here describes no key to do it for you. In both tools the card retries remain in Stripe or Paddle, and the flow's job is the email asking the customer to update the card.
What each is known for
- Klaviyo. Its pricing page names Shopify, Wix and WooCommerce, lists revenue attribution for campaigns and built-in reporting, and describes its free plan as suited to small businesses and start-ups.
- Mailchimp. Standard lists up to 5 audiences, 5 seats and custom-coded templates that can be sent; SMS is an add-on in selected countries; its Transactional product sits on a separate tab.
Moving over with your history
- Export contacts with status, and import unsubscribed people as suppressed.
- Replay old purchase or signup events with a timestamp and the no-trigger flag (backfill on Klaviyo, is_syncing on Mailchimp), or every historic event will fire your welcome flow.
- Authenticate your sending domain and run both tools for a billing cycle.
- Cancel the old plan only after the first full month of flow reports matches.
Which to choose
- Klaviyo for an event-heavy product under 5,000 profiles, where price is level and the Events API is more explicit.
- Mailchimp at 10,000 profiles and above, where it saves $15 to $90 a month at list price and more in year one.
- Either, with caution, for subscription email: neither lists a billing connector, so budget developer time for the webhook handler.
Related reading: Klaviyo vs Brevo, Klaviyo vs Omnisend, Klaviyo vs HubSpot, Loops vs Klaviyo, ConvertKit vs Klaviyo and the comparison index.
Mailchimp vs Klaviyo: common questions
Is Klaviyo more expensive than Mailchimp?
Not at small sizes. Klaviyo's email plan reads $20 at 500 profiles and $100 at 5,000, the same as Mailchimp Standard at 500 contacts and for the 2,501 to 5,000 band. At 10,000 Klaviyo is $150 against $135, and at 25,000 it is $400 against $310. Mailchimp's 50% first-year offers make the early difference larger.
Do the free plans differ?
Hardly. Klaviyo allows up to 250 profiles and 500 email sends a month, plus $5 of mobile messages and $5 of Composer usage. Mailchimp allows 250 contacts and 500 sends a month, with a ceiling of 250 a day. Both stop sending when you pass a limit until the next cycle or until you upgrade.
Which events API handles duplicates better?
Klaviyo's documents a unique_id idempotency key, so duplicates for the same profile, metric and unique_id are dropped; its bulk endpoint takes up to 1,000 events per request. The Mailchimp Events endpoint documentation read for this page describes no equivalent key, so your handler should dedupe by Stripe or Paddle event ID before it posts.
Can either start a flow from a billing webhook directly?
Neither pricing page lists a Stripe or Paddle connector. Both expect your server to receive the webhook and post an event: to Klaviyo as a metric you name, to Mailchimp as an event on a contact already in the audience.