JWT RS256 vs ES256 — Comparing RSA and ECDSA JWT Signing Algorithms

In this tutorial, you will learn about JWT RS256 vs ES256. We cover key concepts, practical examples, and best practices to help you master this topic.

JWT RS256 vs ES256 compares RSA (RS256) and ECDSA (ES256) signing algorithms across signature size, verification speed, key generation, and ecosystem support to help you choose the best algorithm.

What You'll Learn

• Signature size comparison
• Verification speed benchmarks
• Key generation and management
• Security level comparison
• Library and ecosystem support

Why It Matters

RS256 is universally supported but produces 256-byte signatures with slower verification. ES256 produces 64-byte signatures with faster verification but less ecosystem support. DodaTech benchmarks show ES256 verification is 3x faster than RS256 with 75% smaller signatures.

flowchart LR
    A["RS256 (RSA)"] --> B["Signature: 256 bytes"]
    A --> C["Key size: 2048 bits"]
    A --> D["Verification: ~0.5ms"]
    A --> E["Signing: ~2ms"]
    A --> F["Support: Universal"]

    G["ES256 (ECDSA)"] --> H["Signature: 64 bytes"]
    G --> I["Key size: 256 bits"]
    G --> J["Verification: ~0.15ms"]
    G --> K["Signing: ~0.3ms"]
    G --> L["Support: Most libraries"]

What's Next

Explore {{< ilink "JWT" "JWT Algorithm Selection" }} for complete decision criteria, and apply in {{< ilink "JWT" "JWT Best Practices" }}.