SendGrid vs SMTPfast: Which Email API Should You Choose?

Two Different Approaches to Email

SendGrid has been around since 2009 and powers email for companies of every size. SMTPfast is newer, leaner, and built specifically for developers who want to send transactional emails without the overhead.

Here is where each one wins.

Feature Comparison

Pricing

SendGrid killed its permanent free tier in 2025. The 100/day cap is now a 60-day trial, after which you must pick a paid plan.

SMTPfast uses flat monthly plans: Free, Starter ($9), Growth ($19), and Scale ($49). No per-seat fees, optional prepaid credits for overages, and plan limits published in one place.

Where SendGrid Wins

Full email platform. If you need marketing campaigns, contact lists, A/B testing, and a visual template editor alongside your transactional emails, SendGrid has it all in one place.

Dedicated IPs. For high-volume senders who want full control over their IP reputation, SendGrid offers dedicated IP addresses on their Pro plan.

Legacy breadth. If you have a large existing SendGrid setup with marketing campaigns, templates, contacts, SMTP users, and many integrations, SendGrid has more legacy surface area to lean on.

Scale. SendGrid handles billions of emails. They have proven infrastructure at massive scale.

Where SMTPfast Wins

Developer experience. One endpoint, one API key, clean JSON payloads. You can send your first email in under 5 minutes with nothing but fetch().

const res = await fetch("https://smtpfa.st/api/v1/emails", {
  method: "POST",
  headers: {
    Authorization: "Bearer sf_your_api_key",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "[email protected]",
    to: "[email protected]",
    subject: "Order confirmed",
    html: "<h1>Your order is confirmed</h1>",
  }),
});

Compare that to SendGrid's setup process: create an account, verify a sender identity, generate an API key with the right scopes, install the SDK, and learn their multi-layered API.

Pricing transparency. Four clear tiers, no per-seat fees, and optional prepaid credits when you need extra volume without changing plans.

Resend compatibility. If you are already using Resend, switching to SMTPfast is a two-line change. SendGrid requires a full rewrite.

Simplicity. SMTPfast does one thing: send transactional emails reliably. No marketing features to get in the way.

API Comparison

Sending with SendGrid

const sgMail = require("@sendgrid/mail");
sgMail.setApiKey(process.env.SENDGRID_API_KEY);

const msg = {
  to: "[email protected]",
  from: "[email protected]",
  subject: "Order confirmed",
  html: "<h1>Your order is confirmed</h1>",
};

await sgMail.send(msg);

Sending with SMTPfast

await fetch("https://smtpfa.st/api/v1/emails", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SMTPFAST_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "[email protected]",
    to: "[email protected]",
    subject: "Order confirmed",
    html: "<h1>Your order is confirmed</h1>",
  }),
});

Both work. SMTPfast requires no SDK installation - just fetch().

Who Should Use What?

Choose SendGrid if:

• You need marketing email features alongside transactional
• You require SMTP relay for legacy systems
• You want dedicated IP addresses
• You are sending 1M+ emails per month

Choose SMTPfast if:

• You need product email, SMTP relay, and lightweight broadcasts/forms without a large suite
• You want the fastest possible setup
• You value simple, transparent pricing
• You are migrating from Resend and want API compatibility

The Bottom Line

SendGrid is a Swiss army knife. SMTPfast is a scalpel. If you need the full email platform with campaigns, contact management, and SMTP relay, SendGrid is hard to beat. If you need to send transactional emails from your app with minimal setup and clear pricing, SMTPfast is the better fit.