Is this tool suitable for generating TOTP codes for authenticator apps like Google Authenticator?

No. This tool generates static, random numeric codes for SMS/email verification, not time-based (TOTP) or counter-based (HOTP) codes derived from shared secrets.

How does the tool ensure the generated codes are secure?

It uses Node's cryptographically secure crypto.randomInt() function, ensuring the generated numbers are unpredictable and safe for verification scenarios.

Can I generate multiple unique codes at the same time?

Yes, you can generate up to 100 unique, deduplicated codes in a single batch.

What does the 'Exclude ambiguous' option do?

It filters out the digits 0 and 1, which are easily confused with letters like O, o, I, or l, making the codes easier to read aloud or transcribe.

Does the expiry countdown actually invalidate the codes on my server?

No, the expiry countdown is a visual simulation for testing and UI demonstration purposes. You must implement actual code expiration logic on your backend.

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Security

Numeric OTP Generator

Generate cryptographically secure one-time numeric codes (SMS / email verification, raffle codes, event pins) with configurable length (3-10 digits), bulk output, optional ambiguous-digit exclusion, and an optional expiry countdown. Uses crypto.randomInt, not Math.random.

Details

What this tool helps you do

This tool generates static one-time numeric codes for verification scenarios — the kind a service texts or emails to a user. It is intentionally distinct from the RFC 6238 / 4226 TOTP/HOTP generator (which derives codes from a shared secret + time/counter for authenticator apps).

Options:

Digits: 4, 6 (the SMS default), 8, or a custom length from 3 to 10.
Count: generate 1-100 codes at once (deduplicated so each is unique).
Group with spaces: render codes like 123 456 for readability.
Exclude ambiguous (0, 1): drop easily-confused digits so codes read cleanly over the phone.
Expires after: optional validity window (30 s / 1 / 5 / 10 min) shown as a countdown.

Security: randomness comes from Node's crypto.randomInt(), the cryptographically secure source — never Math.random(), which is predictable and unfit for codes.

Use cases: smoke-testing an SMS-OTP login flow, generating raffle/event pins, producing burnable verification codes for QA.

Execution

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Prepared example runs

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1 examples

Generate 5 SMS-style 6-digit codes valid for 5 minutes

Bulk verification codes for testing a login flow, grouped for readability, no ambiguous digits.

<div>Renders 5 grouped 6-digit code cards with a 5-minute countdown banner.</div>

Inputs

Set the required fields, then run the tool.

6 options

SettingsAdjust formats, ranges, numbers, and modes.4

DigitsselectOptionalCustom length (3-10)numberOptionalCountnumberOptionalExpires afterselectOptional

TogglesEnable or disable optional behavior.2

Group with spaces (e.g. 123 456)checkboxOptionalEnabled when checkedExclude ambiguous (0, 1)checkboxOptionalEnabled when checked

Result

Ready for a run

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Samples

Numeric OTP Generator

What this tool helps you do

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Prepared example runs

Inputs

Result

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Prepared example runs

Inputs

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Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Overview

When to use

How it works

Use cases

Examples

1. Bulk SMS Verification Code Generation for QA Testing

2. Generating Ambiguity-Free Event Entry PINs

FAQ

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