SMS & Email OTP verification

SMS & email verification with one-time passwords

Avoid fraud, verify users’ identity & reinforce security. Easily implement one-time passwords via email or SMS.

Try an email OTP flow demo

This working demo generates an OTP and sends it via email.

✉️ Generate OTP

This first step has a flow that verifies if the email domain has a valid MX record, if it's valid, it generates a 4-digit OTP and sends it via email using Mailjet.

Try it using an email with non existing domain and another one which you have access to verify the OTP.

Why use SMS or email verification with Arengu?

Verify & qualify users

One-time passwords help you check users’ identity and get qualified leads. Make sure you acquire users that will convert.

Reinforce security

Data is the new bacon. Protect your users and your business from account takeovers or data theft.

Avoid fraud & block spam

Clean up your database by blocking spam accounts or bots. Avoid fraudulent accounts and optimize your metrics.

Other popular use cases

Use ready-made templates to build complex use cases in minutes. Or build yours from scratch for a completely custom experience.

Powerful alone. Better together.

All-in-one solution to build, automate and scale your user registrations.


Drag & drop form builder

Easily create your custom form with our drag & drop builder. Add multiple steps, require payment details, add custom server-side logic... without writing a single line of code.

  • Forms with Flows

  • Approval workflows

  • Multi-step forms fields

  • Payment fields

Learn about Forms


Visual flow editor

Easily build server-side logic that can be used in your forms or as a standalone product. Create custom validations, integrate with other APIs or automate tasks without coding.

  • Validation flows

  • Eliminate maintenance costs.

  • Easy to integrate with your stack.

Learn about Flows


Hosted static pages

Maximize your conversion rates building dedicated static pages at scale with message-matched content and get the best results for your ad campaigns.

  • Simple HTML templates

  • Automated pages from a .CSV file

  • HTTPS & CDN-hosted assets

  • Mustache template tags

Learn about Pages

Developer friendly

Save development time, embed anywhere with a line of code.

Stack agnostic

Embed it, with a simple line of code, in most popular CMS platforms, landing page builders and development frameworks.

Integrations with any API

Quick integration with almost every API and common ID providers (Auth0, Okta...), adding flexibility to forms and logics.

Save time and resources

We help teams with repetitive and complex actions, building - easy to edit, maintain and scale - templates.

Frequently asked questions

How does an OTP work? How are OTPs generated?
What is an OTP? What does OTP mean?
Why should I use an OTP verification?
Can I set up passwordless forms with OTPs?
What is two-factor authentication (2FA)?
Can I use my own email or SMS provider?
Does Arengu support email templates for OTPs? Can I customize the OTP message?
Does Arengu support a native email address verification action?
Pros and cons of email and SMS verification: Which is the best option?