API Security
Secure your endpoints, authentication, and data transmission. Explore JWT, OAuth2, OWASP Top 10 vulnerabilities, encryption, rate limiting, and defensive architecture.
Defend your APIs against modern threats and misconfigurations
In modern distributed architectures, APIs are the primary target for malicious attacks, unauthorized data scraping, and authentication bypasses. Securing APIs requires defense-in-depth across the transport, gateway, authorization, and storage layers.
Explore battle-tested security guides written by senior engineers, inspect tokens and hashes using privacy-focused crypto utilities, and reference security best practices.
📖Learn API Security
Essential engineering guides for hardening APIs and preventing vulnerabilities.
Mastering API Security: OAuth2 & JWT
Implement OAuth2 and JWT without common vulnerabilities like algorithm confusion and missing expiry.
OWASP API Top 10
The top vulnerabilities still breaking production APIs: BOLA, broken auth, rate limits, and SSRF.
JWT vs Session Cookies
Compare stateless JWTs and stateful httpOnly session cookies for scalable microservices architectures.
Mastering Microservices Security
Zero-trust architecture, mTLS, service-to-service authorization, and API gateway defense.
Spring Boot Security Checklist
10-minute developer checklist for CSRF, CORS headers, Content-Security-Policy, and actuator hardening.
Mastering Secret Management
Beyond application.properties: HashiCorp Vault, AWS Secrets Manager, and environment variables.
🛠️API Security Developer Tools
Browser-side cryptographic utilities that execute 100% locally.
JWT Decoder & Inspector
Decode JWT headers and payloads, inspect timestamp validity, issuer, and signature algorithms.
AES Encrypt & Decrypt
Encrypt and decrypt sensitive payload data using AES-128, AES-192, and AES-256 in CBC or GCM mode.
SHA Hash Generator
Compute SHA-1, SHA-256, SHA-384, and SHA-512 cryptographic hashes for data integrity verification.
HMAC Signature Generator
Generate keyed-hash message authentication codes (HMAC) for signing API webhook payloads.
UUID & Nonce Generator
Generate cryptographically secure v4 UUIDs, API keys, nonces, and random tokens.
🧪Practice with Real APIs (API Playground)
Send live requests, test endpoints, inspect responses, and debug payloads right in your browser.
Test Authentication with Live APIs
Experiment with Bearer tokens, API keys, OAuth2 flows, and rate-limiting responses directly in the interactive sandbox.
Inspect Auth Headers & Payloads
Send authenticated requests and inspect Authorization headers, WWW-Authenticate challenges, and 401/403 status codes.
GitHub API Auth
Test Personal Access Tokens (PAT), OAuth scopes, and fine-grained permissions.
Stripe API Webhooks
Test secret key authorization, idempotent requests, and test-mode credit card handling.
Firebase Auth REST API
Test user token refresh, email/password verification, and anonymous auth payloads.
📋Quick Reference
Security rules, token structures, and defense checklists.
JWT Structure & Claims Cheatsheet
Standard registered claims (iss, sub, aud, exp, nbf, iat), JOSE headers, and validation steps.
Spring Security Cheatsheet
SecurityFilterChain config, CORS, CSRF disable rules, method security, and JWT auth filters.
Security Headers Cheatsheet
HSTS, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, and Referrer-Policy.
SSH & Key Management Cheatsheet
Generating Ed25519 keys, ssh-agent, config profiles, and bastion host port forwarding.
🚀Recommended Learning Path
A progressive path to mastering application and API security.
Transport & Headers
Enforce TLS 1.3, configure CORS correctly, and set HTTP security headers (CSP, HSTS, XFO).
Authentication & JWT
Implement OAuth2 / OIDC token verification, short token expiries, and secure token storage.
Object-Level Authorization
Defend against BOLA (Broken Object Level Authorization) by validating resource ownership on every query.
Rate Limiting & Gateway Defense
Deploy rate limiters, input sanitization, automated secret rotation, and audit logging.
💡Frequently Asked Questions
Common questions and answers regarding API Security.
Always sign JWTs with strong algorithms (RS256 or EdDSA for asymmetric, HS256 with 256-bit secret for symmetric), enforce short expiration times (e.g., 15 minutes), never store sensitive secrets in payload claims, and validate issuer ('iss') and audience ('aud') claims on every request.
🔗Explore Related Topics
Continue learning beyond API Security with related collections.
API Development
REST architecture, error envelopes (RFC 9457), status codes, and API testing.
DevOps & Cloud Security
Docker container security, secret managers, CI/CD credentials, and Linux hardening.
SQL & Injection Defense
Prepared statements, parameterized queries, ORM safety, and database permissions.
Inspect your authentication tokens safely
Decode JWT tokens, inspect claims, and debug signature headers in your browser without transmitting secrets.
Open JWT Decoder →