What Is a Random Token Generator?

A random token generator creates cryptographically secure random strings used for authentication, authorization, and data protection in software applications. Tokens serve as unique identifiers that are practically impossible to guess or predict.

Common Uses

API Keys

Authenticate requests between services and applications

Session Tokens

Maintain secure user sessions across requests

CSRF Tokens

Prevent cross-site request forgery attacks

Password Reset

Secure one-time links for account recovery

Webhook Secrets

Verify payload integrity from third-party services

Encryption Keys

Generate random keys for symmetric encryption

Why Use Cryptographically Secure Randomness?

Standard random number generators (like Math.random()) are not suitable for security purposes because their output can be predicted. This tool uses the Web Crypto API (crypto.getRandomValues()), which provides cryptographically secure pseudo-random numbers backed by the operating system's entropy source.

Insecure

Math.random()

Predictable output patterns
Not cryptographically secure
Vulnerable to attacks
Unsuitable for tokens

Secure

crypto.getRandomValues()

Unpredictable randomness
Cryptographically secure
OS-level entropy source
Production-ready tokens

How to Use

Choose a Format

Select one of the six available output formats based on your requirements:

Hex — Standard format for keys and hashes

Characters: 0-9, a-f

Most common format for API keys, secrets, and cryptographic hashes. Each byte produces 2 hex characters, making it efficient and widely compatible.

Base64 — Compact encoding for HTTP headers

Characters: A-Z, a-z, 0-9, +, /

Compact encoding commonly used in HTTP headers, JWTs, and email attachments. More space-efficient than hex.

Base64URL — URL-safe variant

Characters: A-Z, a-z, 0-9, -, _

URL-safe variant using - and _ instead of + and /. No padding characters (=). Ideal for tokens in URLs and query parameters.

Alphanumeric — Easy to read and type

Characters: A-Z, a-z, 0-9

Human-friendly format that's easy to read, type, and communicate. Safe in all contexts without special character concerns.

Numeric — Digits only for OTPs and PINs

Characters: 0-9

Digits only. Perfect for one-time passwords (OTPs), PIN codes, and verification codes that need to be entered on numeric keypads.

Custom — Define your own character set

Define your own character set for specialized requirements. Useful for domain-specific tokens or when you need to exclude ambiguous characters like 0, O, l, 1.

Set the Length

Use the slider, input field, or preset buttons (16, 32, 64, 128) to set the token length.

Length interpretation: For Hex, Base64, and Base64URL, the length represents bytes of randomness. For Alphanumeric, Numeric, and Custom formats, it represents the number of output characters.

Configure Options (Optional)

Expand Advanced Options to customize your tokens:

Prefix — Add a custom prefix to identify token types (e.g., sk_live_, api_, pk_test_)
Separator — Insert dashes or spaces every N characters for improved readability
Letter Case — Choose lowercase, uppercase, or mixed case output

Generate

Click Generate to create your tokens. Set the quantity (1-50) to generate multiple tokens in a batch. Copy individual tokens or use Copy All to copy the entire batch at once.

Features

Multiple Output Formats

Generate tokens in six formats to match your exact requirements:

Hex for standard keys
Base64 for compact encoding
Base64URL for URLs
Alphanumeric for readability
Numeric for OTPs
Custom character sets

Flexible Length Control

Set the token length with multiple input methods:

Interactive slider
Direct numeric input
One-click presets (16, 32, 64, 128)
Range: 1 to 512
Full control over security strength

Batch Generation

Generate up to 50 tokens at once:

Independent generation per token
Full cryptographic randomness
Copy individual tokens
Copy entire batch with one click

Custom Prefix

Add prefixes to identify token types:

sk_ for secret keys
pk_live_ for production
api_ for API tokens
Distinguish environments at a glance

Readability Options

Make long tokens easier to read and compare:

Add separators (dashes or spaces)
Configurable intervals
Lowercase, uppercase, or mixed case
Break tokens into readable chunks

Entropy Display

Understand your token's security strength:

Real-time entropy calculation (in bits)
See security strength instantly
Make informed decisions
Optimize length and format

Your Data Stays Private: All token generation happens entirely in your browser using the Web Crypto API. No server requests, no storage, no tracking. Your tokens never leave your device.

Frequently Asked Questions

How long should my token be?

For most security applications, 32 bytes (256 bits) is recommended. This provides a security level that is computationally infeasible to brute-force with current and foreseeable technology.

For less critical uses (like short-lived session tokens), 16 bytes (128 bits) is often sufficient and still provides excellent security.

Length	Entropy	Use Case	Security Level
16 bytes	128 bits	Session tokens, temporary codes	Strong
32 bytes	256 bits	API keys, long-term secrets	Excellent
64 bytes	512 bits	Master keys, critical systems	Maximum

Which format should I use?

Hex — Most common for API keys and secrets. Universal compatibility.
Base64URL — Ideal when the token will appear in URLs or query parameters.
Alphanumeric — Best when the token needs to be manually typed or read aloud.
Base64 — Compact encoding for HTTP headers and JWTs.
Numeric — Perfect for OTPs and verification codes on numeric keypads.
Custom — When you need specific character sets or want to exclude ambiguous characters.

What is entropy and why does it matter?

Entropy measures the randomness of a token in bits. Higher entropy means more possible combinations and stronger security against brute-force attacks.

A 128-bit token has 2¹²⁸ possible values — that's 340,282,366,920,938,463,463,374,607,431,768,211,456 combinations, more than the number of atoms in the observable universe.

Security benchmark: 128 bits is considered secure against brute-force attacks for the foreseeable future. Even with quantum computing advances, 256-bit tokens remain extremely secure.

Entropy Comparison

64-bit token Weak

128-bit token Strong

256-bit token Excellent

Is it safe to generate tokens in the browser?

Yes, absolutely. This tool uses crypto.getRandomValues(), which is a cryptographically secure random number generator built into all modern browsers.

OS-Level Entropy

Draws randomness from the operating system's entropy pool, the same source used by server-side generators.

Industry Standard

Web Crypto API is a W3C standard implemented consistently across all major browsers.

Complete Privacy

Tokens are generated entirely client-side. No network requests, no server storage, no tracking.

Same Quality

Provides the same quality of randomness as server-side generators used in production systems.

Why does changing letter case affect entropy?

When you force an alphanumeric token to all-lowercase or all-uppercase, the effective alphabet shrinks from 62 characters (A-Z, a-z, 0-9) to 36 characters (a-z + 0-9 or A-Z + 0-9).

This reduces the number of possible combinations per character, so the entropy decreases accordingly.

Lower Entropy

Forced Case (36 chars)

Lowercase: a-z, 0-9
Uppercase: A-Z, 0-9
~5.17 bits per character
Fewer possible combinations

Higher Entropy

Mixed Case (62 chars)

A-Z, a-z, 0-9
Full alphanumeric range
~5.95 bits per character
Maximum combinations

Recommendation: Use mixed case (default) for maximum entropy unless you have specific requirements for single-case tokens.

Can I use these tokens in production?

Yes. The tokens generated by this tool use the same cryptographic primitives that production systems rely on. However, always ensure your application handles tokens securely:

Store securely — Hash tokens when possible (e.g., API keys in database)
Transmit safely — Always use HTTPS for token transmission
Implement expiration — Set appropriate token lifetimes
Rotate regularly — Periodically regenerate long-lived tokens
Monitor usage — Log and audit token access patterns
Revoke when needed — Implement token revocation mechanisms

The security of a token depends not just on its randomness, but on how your entire system handles, stores, and validates it. Strong tokens are a foundation, not a complete solution.
— Security Best Practices