SMTPfast vs Kit (ConvertKit).

Developer email operations instead of creator marketing funnels.

Kit, formerly ConvertKit, is built for creators selling newsletters, products, and courses. SMTPfast is built for software teams sending transactional, SMTP, broadcast, and form-driven email with delivery logs and SES-backed controls.

SMTPfast

Email API plans for software teams.

Kit optimizes for creator businesses; SMTPfast optimizes for software product email.

Kit (ConvertKit)

Subscriber-based creator marketing plans.

Best for: Creators who need newsletters, landing pages, and sales funnels.

What SMTPfast adds

The useful differences for teams evaluating Kit (ConvertKit).

REST API and SMTP relay for product-triggered email.
Delivery logs, webhooks, suppressions, and domain diagnostics.
Idempotency, batch sending, attachments, and scheduling.
SES-backed controls without creator-funnel complexity.

Short verdict

Choose Kit for creator newsletters, funnels, and landing pages. Choose SMTPfast for developer-owned transactional email, SMTP relay, webhooks, logs, suppressions, and deliverability controls.

Try SMTPfast free

Feature	SMTPfast	Kit (ConvertKit)
Pricing model	Simple volume plans	Subscriber and creator feature tiers
Public free tier	3,000 emails/month	Up to 10,000 subscribers
API & Sending
REST API
Resend-compatible payloads
SMTP relay
Batch sending	100/request
Idempotency keys
Inline images (cid) and automatic plain text		Not published
Customer webhooks
Share links for sent emails		Not published
Webhook event replay		Not published
Email metrics API		Last 90 days only
Marketing & Audience
Broadcast campaigns
Signup forms
Broken link check before sending		Not published
Spread a broadcast over hours	15 min to 72 h	Not published
Workflow automation	Planned
Dynamic segments	Planned
Hosted templates		Broadcast layouts only
Deliverability & Safety
DKIM/SPF/DMARC guidance
Custom MAIL FROM
Suppression management
Marketing opt-outs that keep transactional mail flowing	Per-email category	Not published
Custom tracking domain	Paid plans	Not published
Live event tail
Warmup and abuse controls
Platform Model
Inbound email	Paid plans
Inboxes with threads and drafts	Paid plans	Not published
MCP server for AI agents		Not published
Terraform provider	Official	Not published
Agent skill for coding assistants	Official	Not published
API key scopes	Per key	Not published
Open source	Evaluating
Self-hostable	Evaluating
Team members and roles	Paid plans	Not published
No per-seat pricing

Choose Kit (ConvertKit) if

You are a creator selling newsletters, courses, or digital products.
You need landing pages and subscriber funnels.
Non-technical marketing workflows matter more than API/SMTP operations.

Choose SMTPfast if

You are building software, not an audience.
Your sends are triggered by events in your app, at times nobody chooses.
You need delivery observability, because when a password reset does not arrive it becomes a support ticket.

Migration checklist

1Export subscribers, tags, forms, and unsubscribe state.
2Create an SMTPfast account and generate an API key with email:send scope.
3Add and verify your sending domain with DKIM, SPF, DMARC, and MAIL FROM records.
4Send a low-volume test message and confirm events appear in the SMTPfast logs.
5Move production traffic gradually while watching bounces, complaints, and suppressions.
6Keep creator funnels in Kit unless SMTPfast's simpler forms/broadcasts cover the use case.

Frequently asked questions.

Is SMTPfast better than Kit?

Kit is stronger for creator marketing funnels. SMTPfast is stronger for developer-owned API/SMTP email and delivery operations.

When should I still choose Kit?

Choose Kit when its core strength matches your team: Creators who need newsletters, landing pages, and sales funnels. SMTPfast is a better fit when you want a developer-first SES-backed API with queues, webhooks, tracking, suppressions, and a focused dashboard already handled.

How hard is it to migrate from Kit to SMTPfast?

Most migrations start with domain verification, a test API key, and one low-risk transactional email path. Resend-compatible payloads are especially quick to move; older providers may require mapping template, webhook, and suppression behavior.