Online API Token & Secret Key Generator

Generate high-entropy API keys, webhook secrets, Hex tokens, and Base64URL keys with cryptographic CSPRNG randomness. 100% private in-browser tool.

At a glance

Secure API Token & Secret Key Generator is a free online tool that generates cryptographically secure API tokens, secret keys, Hex digests, and Base64URL secrets using CSPRNG. Hexadecimal, Base64URL, Alphanumeric, NanoID, and custom character pools. It also seamlessly prepends sk_live_, whsec_, ghp_, or custom domain prefixes. All processing is local: nothing is uploaded, and no account is required.

Security Suite: Token Generator Password Generator UUID Generator Hash Generator JWT Decoder QR Generator

100% In-Browser CSPRNG Cryptography

Random values are generated strictly via hardware entropy through window.crypto.getRandomValues(). Zero secrets or keys ever leave your machine.

Cryptographically Secure
Presets:
Primary Cryptographic Secret
256 Bits Entropy Military Grade
Length
64 characters
Entropy Pool
16 chars (Hex)
Total Entropy
256 bits
RNG Source
CSPRNG (Web Crypto)
Generation Parameters
Prepended directly to random entropy
64
1
Generate 1 to 50 tokens at once

True CSPRNG Hardware Entropy

Standard Math.random() is pseudo-random and vulnerable to prediction. This generator utilizes the browser's native Cryptographically Secure Pseudo-Random Number Generator (crypto.getRandomValues) backed by operating system entropy.

Why Prefix API Keys?

Industry leaders like Stripe (sk_live_) and GitHub (ghp_) use prefixing. Prefixes help developers identify key scopes instantly and allow secret scanning tools (like GitHub Secret Scanning) to detect accidentally committed tokens.

Hex vs. Base64URL

Hexadecimal is universally supported by all crypto libraries (HMAC, SHA-256 digests). Base64URL packs 50% more entropy per character, making it ideal for compact URL tokens, OAuth tokens, and cookie signatures without escaping.

Why Use This Secure API Token & Secret Key Generator?

100% Hardware CSPRNG: Generates true cryptographic entropy via window.crypto.getRandomValues().
Zero Modulo Bias: Uses unbiased rejection sampling across all character sets and length boundaries.
Multiple Formats: Hexadecimal, Base64URL, Alphanumeric, NanoID, and custom character pools.
Custom Prefix Support: Seamlessly prepend sk_live_, whsec_, ghp_, or custom domain prefixes.
Live Cryptographic Entropy Meter: Instant real-time calculation of total entropy bits and strength rating.
Batch Generation & .env Export: Generate up to 50 tokens at once and download directly as a .env configuration.

How to Use Secure API Token & Secret Key Generator

1

Select Format or Preset

Choose Hexadecimal, Base64URL, Alphanumeric, or select a preset like Stripe (sk_live_) or Webhook secret.

2

Configure Length and Prefix

Adjust entropy length (8 to 256 chars), add an optional custom prefix, and pick single or batch quantity.

3

Copy or Export Secrets

One-click copy the high-entropy token to your clipboard or download as a .env / .txt file.

Worked example: 32-Char Hex Token With Prefix

The engine draws hardware entropy via window.crypto.getRandomValues and maps bytes to the charset with rejection sampling to eliminate modulo bias, locally.

Token Settings Source 
Format: Hexadecimal, Length: 32, Prefix: sk_live_  Quantity: 1
Cryptographic Token and Entropy Processed 
sk_live_9f3ac41d7e284b6fa0c5e813d2f47028 (40 chars total). Entropy: 128 bits, strength: Very Strong.

Technical Specifications & Engine Details

Technical specifications and engine details for Secure API Token & Secret Key Generator
Specification Details
Supported Formats Text / Input → TEXT
Execution Mode 100% Client-Side In-Browser (client)
Browser Requirements Requires modern web browser with Web Cryptography API (SubtleCrypto).
Performance Constraints Client browser memory limit (typically 1–2 GB RAM); processing speed depends on local device CPU.
Maintained by Pragyan Pahadi

100% Client-Side Privacy Guarantee

All cryptographic token generation occurs strictly inside your browser using client-side CSPRNG. Zero keys, secrets, or seeds are transmitted over any network.

Frequently Asked Questions

How are these tokens cryptographically secure?
This tool generates random bytes using the native Web Crypto API (window.crypto.getRandomValues()), which gathers operating system hardware entropy. Unlike Math.random(), CSPRNG output cannot be predicted by an adversary.
What is modulo bias and why does this tool eliminate it?
When mapping random bytes to a character set whose size does not divide 256 evenly, standard modulo arithmetic skews probability toward lower characters. This tool uses rejection sampling to guarantee a mathematically uniform distribution for every character.
Why should API keys have prefixes like 'sk_live_'?
Prefixes allow developers and security scanners (such as GitHub Secret Scanning) to immediately detect key type, service origin, and environment (production vs test), and prevent accidental exposure in public repositories.
Are generated keys sent to any server or recorded?
No. All generation takes place 100% locally in your browser memory. No network requests are made, ensuring complete confidentiality.

Methodology

This tool runs entirely in your browser. The example above shows a representative input and the result it produces.

Last updated .

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