Real email OTP verification · Free plan available · No credit card

Email OTP 
verification. 

Nixify sends actual 6-digit OTP codes to a real inbox over SMTP. Single-use, rate-limited, brute-force-protected. A Free plan is available — no email credentials required.

No credit card · Free plan available · Upgrade anytime

Features

Built for production, free to start

Everything you need to verify email addresses with real 6-digit OTP codes — a Free plan is available, no credit card required.

Real SMTP delivery

Codes delivered via real SMTP through managed email infrastructure. The transport is configurable by the operator — no customer SMTP credentials required.

Single-use, rate-limited

Every 6-digit code is one-time, expiry-bound, and protected against brute force and resend abuse.

Atomic single-use verification

Constant-time HMAC compare, atomic single-use enforcement, and DB-backed rate limiting — no in-memory state.

Free plan available

A Free plan is available with no credit card required. Sign up and verify your email to get started.

Managed delivery

Nixify handles email delivery through managed mail infrastructure. Hosted API customers do not provide personal email credentials.

Serverless-safe

All state in PostgreSQL. No in-memory rate limits or counters. Deploys free on Vercel Hobby tier.

How it works

A code. In an inbox. Verified.

No magic links to click, no third-party apps to install. Just a 6-digit code that works everywhere.

User enters their email
We send a 6-digit code via SMTP
User enters the code — verified

Nixify

Verify your email

Enter this code to continue

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Expires in 10 minutes

Email Themes

Email templates & branding

Customize every email with your logo, colors, and fonts. No HTML knowledge required.

Nixify
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Minimal
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Discord
Nixify
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Cyber
Nixify
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Luxury
Nixify
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Glass
Nixify
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Stripe
Developer Experience

Integrate with the REST API

Use the REST API from JavaScript, cURL, Python, or any HTTP client.

01// Send a 6-digit OTP via the REST API
02const sendRes = await fetch('https://nixify.vercel.app/api/v1/otp/send', {
03 method: 'POST',
04 headers: {
05 'Authorization': 'Bearer mg_live_xxx',
06 'Content-Type': 'application/json',
07 },
08 body: JSON.stringify({
09 email: 'user@example.com',
10 purpose: 'signup',
11 }),
12});
13const sendData = await sendRes.json();
14console.log(sendData.otp_request_id);
15
16// Verify it (use the same purpose)
17const verifyRes = await fetch('https://nixify.vercel.app/api/v1/otp/verify', {
18 method: 'POST',
19 headers: {
20 'Authorization': 'Bearer mg_live_xxx',
21 'Content-Type': 'application/json',
22 },
23 body: JSON.stringify({
24 email: 'user@example.com',
25 code: '482917',
26 purpose: 'signup',
27 }),
28});
29const verifyData = await verifyRes.json();
30console.log(verifyData.verified);
Capabilities

What Nixify includes

Real OTP email verification — with a Free plan available.

Real SMTP deliveryFree plan
Single-use codesAtomic single-use
Brute-force protectionMax 5 attempts
Rate limiting (DB-backed)DB-backed
Email theme customizationUp to 20 (Pro)
Sandbox modeTest mode
Get started

From signup to your first OTP

Step 1

Sign up

Enter your email and a password.

Step 2

Get a code

We email you a 6-digit verification code.

Step 3

Verify

Enter the code to confirm your email.

Step 4

Start sending

Complete your profile to finish setting up your account.

FAQ

Questions?

Yes. The Free plan is available at no cost with usage limits. No credit card required, no hidden fees. Upgrade to Pro or Max for higher usage.

Yes. OTP codes are delivered via real SMTP through managed email infrastructure. No mocks, no stubs — real delivery to a real inbox. You do not need to provide personal email credentials to use the API.

No. Hosted Nixify handles OTP email delivery through managed mail infrastructure. API customers do not provide personal Gmail or SMTP credentials. Deployment operators can configure a supported mail transport separately.

Codes are generated with crypto.randomInt, stored as HMAC-SHA256 hashes, compared with timingSafeEqual (constant-time), and enforced single-use via atomic database writes.

Yes. Nixify includes professionally designed email templates with branding customization — logo, colors, fonts, layout. Template and branding availability depends on your plan: Free includes 2 templates, Pro includes 20, Max includes unlimited. Custom branding is available on Pro and Max. See Pricing for current limits.

Ready to verify?

Start sending OTP emails with the API. No credit card, no setup fee, no lock-in.