Substack

Substack is closed and opinionated: 10% revenue cut, no API, no custom domains for free, but distribution and recommendations are real. Largely outside the developer toolchain conversation.

At an early stage the deciding factors are what the free tier actually covers, what the first paid invoice looks like, and how much of a founding engineer's week the setup costs. Feature depth that only matters at a million sends a month is noise until it is not.

Against a waitlist, a launch announcement, onboarding email, and the first transactional sends, Substack covers developer experience and scheduling, and does not cover operating track record, SDK breadth, and webhook coverage. Whether that gap matters depends on how central those are to the build.

• Free tier: Free, 10% of paid subscriptions
• Best published rate per 1,000: Tiers not published in comparable form
• Starts at: 10% revenue cut
• DX score: 2/10
• Deliverability: Reasonable for content-driven newsletters.
• Operating since: 2017
• Scheduling: Yes
• SDKs: None
• Webhooks: No

Reasonable for content-driven newsletters.

Writers who prioritize distribution over flexibility.