Resend vs Postmark
Resend is a developer-first transactional email API, known for the cleanest DX in the category and for React Email, with a free tier of 3,000 emails/month. Postmark is a transactional-only specialist with the strongest deliverability and time-to-inbox reputation in the category, with a free tier of 100 emails/month. The choice usually comes down to whether you optimise for developer experience, deliverability reputation, or price at volume.
Resend
A developer-first transactional email API, known for the cleanest DX in the category and for React Email.
- Free tier
- 3,000 emails/month
- Pricing shape
- Transactional priced per volume, with Marketing (audiences + broadcasts) billed separately by contact count — so a team doing both pays on two axes.
- Strongest at
- The API shape and error semantics that set the modern standard — we deliberately match them
- React Email is the de-facto way to build email in React, and Resend maintains it
- A permanent free tier at the same 3,000 emails/month we offer
- Broad SDK coverage, including Go, PHP, and Elixir, which we do not have yet
- Pick it when
- You need an SDK we don't ship yet — Go, PHP, Elixir, or Rust
- You only ever send transactional email and want the most battle-tested option in that lane
- You want the largest community and the most third-party tutorials to lean on
Postmark
A transactional-only specialist with the strongest deliverability and time-to-inbox reputation in the category.
- Free tier
- 100 emails/month
- Pricing shape
- Priced per volume at a premium to the rest of the category, deliberately — they separate transactional and broadcast streams to protect reputation.
- Strongest at
- The best-regarded deliverability and time-to-inbox record in the category, and it is earned
- Separate message streams keep marketing sending from ever touching transactional reputation
- Support with a reputation for genuine technical depth
- 45 days of detailed message history and excellent debugging tooling
- Pick it when
- A missed email is expensive — banking password resets, MFA codes, booking confirmations
- You want transactional sending physically isolated from anything marketing-shaped
- You are willing to pay a premium specifically for inbox placement
Pricing and free-tier details for both providers last verified 2026-07. These change often — check each provider's own pricing page before deciding.
Disclosure: we also build an email API
This comparison is published by Unitpost, which competes with both providers above. We have kept this page about them because that is the question you searched for. If you want our side of it, we have honest head-to-heads at Unitpost vs Resend and Unitpost vs Postmark, both of which list where those providers beat us.
Considering a third option?
Transactional and marketing email in one product
3,000 emails a month free. Migrate from either provider with a read-only API key — nothing is written until you accept.