FlockStack vs Substack

The short version

Substack and FlockStack charge in opposite ways. Substack takes 10% of the revenue from paid subscriptions: its Going paid page says writers keep 90% minus credit card fees. FlockStack takes nothing from what you sell and charges for the emails you send.

For a free newsletter, Substack has no revenue share to take, and FlockStack is free until you pass the Free plan's limits. For a newsletter with paying readers, the 10% grows with every paid reader, while a FlockStack plan changes only when your list or sends pass a plan's limits. Where the two meet is below.

Choose Substack if

• You want readers to find you inside the platform. Substack has Notes, which you can schedule on web, iOS and Android. FlockStack has an opt-in recommendations directory and no reader network of its own.
• You publish video or live shows. Substack has a desktop Recording Studio for solo video and conversations with up to two guests, and live video. FlockStack has none.
• You want nothing to pay until you earn. Substack's charge is a share of revenue, so a newsletter with no paid subscribers has no share to pay.
• You don't plan to charge for your newsletter. A free list that outgrows FlockStack's Free plan needs a paid plan, which is a cost a free list on Substack doesn't have.

Choose FlockStack if

• You charge for subscriptions and earn enough. FlockStack takes 0% of what you sell. Readers pay your own Stripe account, and Stripe's processing fees apply on both platforms.
• You want the code. FlockStack is open source under the AGPL-3.0 at github.com/ankurmans/flockstack, and can run on your own server. Self-hosted newsletter software covers what that takes.
• 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, on every plan. See the newsletter API.
• You want a plan price you can plan around, set by the emails you send, with a written 90 days' notice before it rises and a cap you set on extra emails.

Where the break-even is

Substack's 10% equals FlockStack's smallest paid plan ($9 a month) at $90 a month of subscription revenue. Below that, Substack's share is the smaller sum. Above it, a FlockStack plan costs less, and the gap widens with revenue until your list needs the next plan.

Stripe's processing fees apply on both for payments made on the web, and are left out of every figure on this page. Purchases made in Substack's iOS app can go through Apple instead; they aren't in these figures either.

Three months, worked out

The same three months as on the comparison page, each with its assumptions in the first cell. Substack's column is 10% of what readers pay, per its Going paid page. Enter your own numbers in the newsletter cost calculator.

The first and last rows have no paying readers, so there is no revenue for Substack to take, and in those two months Substack costs less: FlockStack costs the plan that holds the list, with extra emails where the sends go past it. The middle row is where the two cross: with a share of the list paying, Substack's 10% is larger than a FlockStack plan.

Fees on paid subscriptions

FlockStack sets no application fee on a sale, and its code refuses to send one. Readers pay through Stripe Checkout into your own Stripe account, so your sales, refunds and payouts are in your Stripe dashboard. Stripe's processing fees come off each payment on Substack and on FlockStack. FlockStack's own plan, which you need to sell, is a separate cost. The paid newsletter platform page has the details.

Apple billing and moving your readers

Substack's in-app purchase FAQ, posted August 18, 2025, says in-app purchase is enabled for all paid publications in its iOS app in the countries where it is on, that a creator can't opt out, and that Apple takes 15% to 30%. It also says Apple doesn't transfer billing relationships between platforms, so a subscriber billed by Apple has to be invited to subscribe again elsewhere. Substack keeps its 10% based on the original web price. On FlockStack, readers pay your own Stripe account through Checkout, so there is no app-store billing in between. Check Substack's FAQ for the countries and terms that apply to you.

What writers say

Examples, not a survey. In Digiday on April 9, 2025, Marisa Kabas said she valued not giving Substack 10 percent of every subscription after she left, and Luke O'Neil said he paid Substack about ten thousand dollars a year to host his blog. In a story The Verge published and Slashdot republished on May 14, 2026, Sean Highkin said his yearly cost fell from $4,968 on Substack to $2,052 on Ghost with an add-on. These are writers who chose to leave; they are not a measure of what Substack's writers think overall.

What this page leaves out

It compares what Substack publishes on its own pages and what FlockStack's plans and docs say. It does not compare editors, deliverability, sending addresses, automations, analytics or support, which we haven't tested side by side, and it makes no claim about how Substack's email reaches inboxes. Substack ships often, so check its pages for the current terms before you decide. For more options than one rival, see Substack alternatives. FlockStack is not affiliated with Substack.

Moving from Substack

FlockStack reads a Substack subscriber export as it is, and imports the ZIP of your posts from Substack's Import/Export settings as sent issues dated as before, with no email going out. Paying readers don't move over as paying subscribers. Switch from Substack has the steps in order.