How these rankings are produced
Rankings on this site are editorial. They are produced by reviewing each provider's public documentation, pricing pages, status pages, and SDK repositories, and by drawing on independent third-party deliverability tests where available. The site is not affiliated with any vendor and does not run an affiliate program.
Inputs
- Public documentation: API surface, idempotency support, webhook design, retry semantics, SDK quality.
- Pricing pages: free tiers, starting paid tier, model (volume, tiered, subscriber-based, pay-as-you-go), notable feature gates.
- Independent inbox-placement tests: third-party studies that send to seed lists across Gmail, Outlook, Yahoo, and others.
- Public incident history: status pages, RCA write-ups, and large outages within the past 18 months.
- SDK repositories: maintenance pace, language coverage, type completeness.
Scoring
The DX score (1 to 10) is a single subjective number based on:
- SDK breadth and code quality across major languages.
- Idempotency support and error model.
- Speed of first-send: minutes from sign-up to a delivered message.
- Quality of the event log and message inspection tooling.
Deliverability is a qualitative note rather than a numeric score, because public test data is intermittent and shared-IP pools change. Numeric inbox placement is cited only when a recent independent study supports it.
Update cadence
Each provider profile carries a lastChecked date. Pricing changes faster than features. When pricing pages move, the affected profiles are reviewed and dated again. Substantive feature changes prompt a full re-read of the docs.
No affiliates, no sponsors
There are no affiliate links, sponsored placements, or paid reviews. If that ever changes, it will be disclosed globally, on each affected page, and rankings will continue to be produced independently of any commercial relationship.
Conflicts and corrections
Provider data lives in src/data/providers.ts in the open-source repository. Pull requests with corrections are welcome.