Compare
FlockStack vs Mailchimp
By FlockStackPublished
| FlockStack | Mailchimp | |
|---|---|---|
| What the price follows | The emails you send in a month, with a cap on active subscribers | Contacts, in bands, with a monthly send limit on each plan |
| Free plan | 2,500 subscribers and 10,000 emails a month, with 2 automations and paid subscriptions | 250 contacts, 500 sends a month and 250 a day, with Mailchimp branding |
| What counts toward the limit | Active subscribers; dormant readers are set aside | Subscribed, unsubscribed and non-subscribed contacts; cleaned, pending, archived and deleted ones don't count |
| Cut of paid subscriptions | 0%. Stripe's fees apply | No paid newsletter feature is listed on its pricing pages |
| Automations | 2 on Free; up to 50 a newsletter on a paid plan | A preview on Free; up to 4 steps a flow on Essentials; up to 200 flow points, with branching, on Standard and Premium |
| Segmentation | Up to 50 saved segments on a newsletter, with 13 kinds of condition, on every plan | Basic on Free and Essentials, advanced on Standard and Premium; tags on every plan |
| API | REST API on every plan | Marketing API; its pages don't say whether Free includes it |
| MCP server for agents | Read and write tools on every plan, the Free plan included | An official MCP server that searches its documentation only; apps for Claude and ChatGPT in some countries |
| Code | Open source (AGPL-3.0); run it yourself or use FlockStack Cloud | Hosted by Mailchimp |
The short version
Mailchimp does more than send newsletters: its pages list SMS and a long list of integrations. Its price follows the number of contacts you hold, in bands, and each plan limits the emails you can send in a month. FlockStack is for newsletters, priced by the emails you send, with its API and MCP server on every plan, and its code is open source.
On monthly billing, a weekly newsletter costs less on FlockStack at every list size in the table below, per Mailchimp's pricing page read on October 21, 2026. If you use Mailchimp for more than a newsletter, for SMS or for its integrations, FlockStack does not replace those.
Choose Mailchimp if
- You need more than email. Mailchimp's pricing page, read on October 20, 2026, lists SMS marketing as an add-on and a long list of integrations, with phone support on its Premium plan. FlockStack sends email newsletters and has none of those.
- You need advanced segmentation and long automation flows. Mailchimp lists advanced segmentation and flows of up to 200 points with branching on Standard and Premium. FlockStack has segments and branching automations too, but check newsletter automation against the flows you run.
- You want a team on one account. Essentials includes 3 seats, per the plan comparison. FlockStack isn't built around team roles today, so check its documentation against what your team needs.
- Your list is small and you send rarely. Mailchimp's Free plan holds 250 contacts and 500 sends a month. Compare that with FlockStack's Free plan in the table.
Choose FlockStack if
- You send a newsletter on a schedule a plan holds. You pay for the emails, and the cap is on active subscribers: readers who stop opening are set aside as dormant and don't count. Mailchimp counts unsubscribed contacts toward its limit and bills the peak total in the period.
- You want to charge readers. FlockStack sells paid subscriptions, gifts and one-time products on every plan, through your own Stripe account, with a 0% cut. Mailchimp's pricing pages list no paid newsletter feature. See the paid newsletter platform page.
- You want agents to run it. The REST API has 234 endpoints, and the MCP server lets ChatGPT, Claude, Cursor or Codex use the same actions, with write access on every plan. Mailchimp's official MCP server searches its documentation and does not act on your account. See the newsletter API and the MCP server.
- You want the code. FlockStack is open source under the AGPL-3.0 at github.com/ankurmans/flockstack. You can run it on your own server. Self-hosted newsletter software covers what that takes.
What each costs at the same list size
Mailchimp sells Essentials, Standard and Premium by contacts in bands, at the regular monthly rate it shows as "starts at", and limits sends to 10, 12 or 15 times the band's contacts, by plan. The table shows the lowest-priced Mailchimp plan whose limit covers a weekly issue to every contact, beside the FlockStack plan that holds the same list. Mailchimp's pages advertise 15% off the first 12 months from 10,000 contacts; this is the regular rate. The plans do not include the same things: Essentials has up to 4 steps in an automation flow, and FlockStack's plans include the features on the pricing page.
| Subscribers | FlockStack per month | Mailchimp per month |
|---|---|---|
| 1,000 | $0 (Free) | $26.50 (Essentials, priced for up to 1,500) |
| 5,000 | $9 (Starter) | $75 (Essentials, priced for up to 5,000) |
| 10,000 | $29 (Growth) | $110 (Essentials, priced for up to 10,000) |
| 25,000 | $29 (Growth) | $270 (Essentials, priced for up to 25,000) |
| 50,000 | $59 (Pro) | $385 (Essentials, priced for up to 50,000) |
Mailchimp's yearly prices are not on its pricing page, so the table shows the monthly rate. A FlockStack yearly plan costs 10 months' price instead of 12. The newsletter cost calculator works out your own list, sends and paying readers.
Three newsletters, worked out
The calculator's three examples, billed monthly. Fees are the platform's own share and card processing at Stripe's standard US rate. Mailchimp lists no fee for selling subscriptions, so the table shows "payment fees not listed" where readers pay.
| Newsletter | FlockStack | Mailchimp |
|---|---|---|
| A free weekly newsletter: 2,000 subscribers, 4 issues a month, 8,000 emails a month, billed monthly | $0 (Free) and no fees | $45 (Essentials) and no fees |
| A weekly newsletter with some paying readers: 10,000 subscribers, 4 issues a month, 40,000 emails a month, 500 paying readers at $8 a month, billed monthly | $29 (Growth) and $266 in fees | $110 (Essentials) and payment fees not listed |
| A larger weekly newsletter: 50,000 subscribers, 4 issues a month, 200,000 emails a month, 1,500 paying readers at $10 a month, billed monthly | $59 (Pro) and $885 in fees | $385 (Essentials) and payment fees not listed |
Fees on paid subscriptions
FlockStack sets no application fee on a sale, so it takes 0%. Readers pay your own Stripe account and Stripe's processing fees apply. Mailchimp's pricing and plan pages, read on October 21, 2026, list no paid newsletter feature, so there is no Mailchimp share of subscriptions to compare. Its own guide to earning from a newsletter describes charging subscribers as one way to earn but names no Mailchimp feature for it, and its integrations directory lists a paid third-party app for selling subscriptions that needs a Stripe account. We could not read the fee on sales through Mailchimp's online store, so this page makes no claim about it.
Automations and segmentation
Per Mailchimp's plan comparison, read on October 21, 2026, its Free plan has a preview of automation flows. Essentials has flows of up to 4 steps without branching, and Standard and Premium allow up to 200 flow points with multiple start points and branching. Segmentation is basic on Free and Essentials and advanced on Standard and Premium, and tags are on every plan.
FlockStack's Free plan has 2 automations besides the welcome email, and a paid plan can have up to 50 a newsletter, with 15 triggers and 10 kinds of step, among them waits, branches, splits and webhooks. A newsletter can save up to 50 segments, built from 13 kinds of condition, on every plan.
API and agents
Mailchimp's developer pages describe a Marketing API with a limit of 10 simultaneous connections per user and a 120-second timeout. They do not say whether the Free plan includes API access, so this page does not claim it. Its official MCP server searches the documentation and, per the page, does not search or act on your Mailchimp account. Mailchimp's May 28, 2026 announcement says its apps in Claude and ChatGPT are available to users in the US, Canada, the UK and Australia.
FlockStack's REST API and MCP server have the same 234 actions and write access on every plan.
Where FlockStack is the weaker pick
- No SMS and fewer ready-made integrations. FlockStack connects through its API, webhooks and Zapier and Make.
- Not built around teams, and no mobile app.
- Your past campaigns don't come with you. FlockStack imports past posts only from Substack, beehiiv, WordPress and Ghost exports.
- Paying subscribers can't be moved across yet. FlockStack can't attach a subscription that exists on another platform to a contact.
What this page leaves out
It compares what Mailchimp publishes on its pricing, plan comparison, help and developer pages, and what FlockStack's plans and docs say. It does not compare editors, templates, deliverability, reporting or support, which we haven't tested side by side. Mailchimp's pages were read in US dollars; a different region can show different prices. For more options than one rival, see Mailchimp alternatives. FlockStack is not affiliated with Mailchimp.
Moving from Mailchimp
FlockStack reads a Mailchimp contact export as it comes, with each reader's status and signup date. Automations, templates and campaigns stay behind. Switch from Mailchimp has the steps in order.
Sources
- Mailchimp's plans, the monthly price by contacts, each plan's send limit, the Free plan's limits, the first-year offer for larger audiences, and the plan comparison (automations, segmentation, seats): mailchimp.com, checked
- Mailchimp's help center on pricing plans: the Free plan's contact, send and daily limits, and the definitions of a contact and a send: mailchimp.com, checked
- Mailchimp's help center on additional charges: which contacts count toward the limit, and billing on the peak contact total: mailchimp.com, checked
- Mailchimp's developer documentation: the rate limit of 10 simultaneous connections, and the official MCP server that searches documentation: mailchimp.com, checked
- Mailchimp's developer documentation for its MCP server: it searches the documentation and does not act on an account: mailchimp.com, checked
- Mailchimp's announcement of the Mailchimp apps in Claude and ChatGPT (May 28, 2026), available to users in the US, Canada, the UK and Australia: mailchimp.com, checked
- Mailchimp's pricing page as first read on October 20, 2026: SMS marketing as an add-on, the list of integrations, and phone support on Premium: mailchimp.com, checked
- Mailchimp's guide to earning from a newsletter, which names no Mailchimp feature for charging subscribers: mailchimp.com, checked
- Mailchimp's integrations directory: Campaignzee, a paid third-party app for selling subscriptions to a newsletter, which needs a Stripe account: mailchimp.com, checked
- FlockStack's README: contact imports from beehiiv, Substack, Mailchimp, Kit and other platforms read their CSV exports as they are, with each reader's status and signup date: github.com, checked
- FlockStack's moving guide: which exports it reads, what a contact import does and doesn't carry, and that paid subscriptions don't move: flockstack.io, checked
Questions
- Does FlockStack cost less than Mailchimp?
- It depends on how you send. On monthly billing, with one issue a week to every subscriber, the table on this page shows a FlockStack plan costing less than Mailchimp at each list size, per Mailchimp's pricing page read on October 21, 2026. The plans differ in what they include, and a daily sender uses a FlockStack plan's emails faster.
- Is Mailchimp free?
- Mailchimp has a Free plan, per its pricing pages read on October 21, 2026: 250 contacts, 500 sends a month and 250 a day, one audience and one seat, without scheduling, A/B tests or advanced segmentation. FlockStack's Free plan holds 2,500 subscribers and 10,000 emails a month, with 2 automations and paid subscriptions.
- Does Mailchimp count unsubscribed contacts toward my plan?
- Per its help center, read on October 21, 2026, yes. Subscribed, unsubscribed and non-subscribed contacts count toward a plan's contact limit; cleaned, pending, archived and deleted contacts don't. The bill follows the peak total in the billing period, so a smaller list in mid-cycle doesn't lower that cycle's bill.
- Can I sell paid subscriptions with Mailchimp?
- Mailchimp's pricing and plan pages, read on October 21, 2026, list no paid newsletter feature, and its own guide to earning from a newsletter names no Mailchimp feature for charging subscribers. Its integrations directory lists a paid third-party app that sells subscriptions, which needs a Stripe account. FlockStack sells paid subscriptions on every plan with a 0% cut.
- Can I move from Mailchimp to FlockStack?
- Your contacts, yes. Export them from Mailchimp as a CSV and import the file on the Contacts page: FlockStack reads Mailchimp's contact export as it comes, with each reader's status and signup date. Your automations, templates and past campaigns don't move, because FlockStack imports past posts only from Substack, beehiiv, WordPress and Ghost exports. Paying subscribers can't be moved across yet.
- Does Mailchimp have an API or MCP server?
- Mailchimp has a Marketing API with a limit of 10 simultaneous connections per user. Its official MCP server searches its developer documentation and does not act on your account, and it lists apps for Claude and ChatGPT for users in the US, Canada, the UK and Australia. FlockStack's MCP server reads and writes your newsletter on every plan.
Move your list from Mailchimp
Export your audience from Mailchimp, then import the file on the Contacts page.
Import your list