What is an API Key?
An API key is a unique identifier used to authenticate requests to an API (Application Programming Interface). It acts as a secret token that allows applications to communicate securely with servers and services. API keys are essential for controlling access, tracking usage, and ensuring that only authorized applications can access your API endpoints.
API Key Formats Explained
Hexadecimal Format
Uses characters 0-9 and a-f. Compact and efficient, commonly used in cryptographic applications. Example: a3f5c9d2e8b14f7a
Base64 Format
URL-safe encoding using A-Z, a-z, 0-9, -, and _. Efficient for transmitting binary data. Popular for JWT tokens and OAuth. Example: aGVsbG8gd29ybGQ
Alphanumeric Format
Uses uppercase, lowercase letters and numbers. Highly readable and easy to communicate. Example: Kx9mPq2Tn5Wv8Zr
UUID v4 Format
Universally Unique Identifier with 128-bit value. Globally unique with extremely low collision probability. Example: 550e8400-e29b-41d4-a716-446655440000
Best Practices for API Keys
- Never commit to version control: Keep API keys out of Git repositories and public code
- Use environment variables: Store keys in .env files or secure configuration management
- Rotate regularly: Change API keys periodically to minimize security risks
- Implement rate limiting: Protect your API from abuse with request throttling
- Use HTTPS only: Always transmit API keys over encrypted connections
- Separate keys by environment: Use different keys for development, staging, and production
- Monitor usage: Track API key usage to detect suspicious activity
- Implement expiration: Set expiration dates for temporary access
Common Use Cases
- REST API Authentication: Authenticate requests to RESTful web services
- Third-Party Integrations: Connect to services like Stripe, SendGrid, Twilio
- Microservices Communication: Secure inter-service communication
- Mobile App Backends: Authenticate mobile applications
- Webhook Verification: Verify webhook payloads from external services
- IoT Device Authentication: Secure communication with IoT devices
Prefix and Suffix Conventions
Many services use prefixes to identify key types and environments:
Common Prefixes
sk_live_- Live secret keysk_test_- Test secret keypk_- Public keyapi_- General API keykey_- Generic key prefix
Common Suffixes
_prod- Production environment_dev- Development environment_v1- API version_2024- Year identifier
Security Considerations
Client-Side Generation: All API keys on this page are generated entirely in your browser using cryptographically secure random number generators. No keys are sent to our servers or stored anywhere.
Sufficient Entropy: Our generator uses crypto.getRandomValues() which provides cryptographically strong random values suitable for security purposes.
Key Length: We recommend using at least 32 characters for production API keys to ensure adequate security against brute-force attacks.
Frequently Asked Questions
How secure are these generated API keys?
Very secure. We use the Web Crypto API's crypto.getRandomValues() which provides cryptographically strong random values. The keys are generated entirely client-side and never leave your browser.
What format should I use for my API?
It depends on your requirements. Hexadecimal is compact and efficient. Base64 is URL-safe and commonly used for tokens. Alphanumeric is highly readable. UUID v4 provides global uniqueness. Choose based on your specific needs.
Can I use these keys in production?
Yes! The keys are cryptographically secure and suitable for production use. However, always follow security best practices: use HTTPS, store keys securely, implement rate limiting, and rotate keys regularly.
How long should my API key be?
For production use, we recommend at least 32 characters. Longer keys (64-128 characters) provide additional security margin. The exact length depends on your security requirements and the format you choose.
Should I include prefixes in my API keys?
Yes, prefixes are highly recommended. They help identify key types (public vs secret), environments (test vs live), and make it easier to detect accidentally exposed keys in code repositories.