Abstract—This paper presents an extended performance comparison of browser-side cryptographic primitives implemented in WebAssembly (Wasm) and JavaScript. Building on our original RSA PKCS #1 v1.5 benchmark, we introduce two widely deployed patterns: a hybrid Advanced Encryption Standard-Rivest-Shamir-Adleman (AES–RSA) model reflecting real-world handshake-plus-bulk encryption workflows, and the Ed25519 elliptic-curve signature scheme evaluated across four variants (pure JavaScript, WebCrypto, Wasm non-batch, and Wasm batch). Metrics including single-operation latency, 1 000-iteration throughput, signing time, and verification time were measured under identical Docker-isolated conditions. Results confirm that Wasm consistently outperforms JavaScript in raw computational tasks, particularly decryption and signing, due to its pre-compiled binary format and low memory overhead. However, JavaScript leverages Just-In-Time optimisations to achieve comparable performance during long iterative workloads, making it a viable option for general-purpose applications. Extending the study to Ed25519 reveals that Wasm batch verification delivers the highest throughput, while WebCrypto provides a balanced compromise between ease of use and speed. The hybrid RSA–AES experiment demonstrates that asymmetric cost is amortised once AES-GCM secures the data channel, shifting the performance bottleneck to symmetric operations. These results underscore the applicability of Wasm in latency-critical or resource-constrained environments and provide actionable guidance on when to prioritise native-speed Wasm modules, JavaScript WebCrypto APIs, or mixed pipelines. The dataset and benchmarking framework are released as an open benchmark to support further research into secure, energy-aware web-application design.