JavaScript is single-threaded, but Web Workers let you run scripts in background threads. Keep your UI responsive while handling heavy computations.
The Problem
Dedicated Workers
Creating a Worker
Inline Workers
Transferable Objects
Worker Pool
Shared Workers
Comlink (Simplified API)
Use Cases
Good for Workers:
✓ Image/video processing
✓ Data parsing (CSV, JSON)
✓ Cryptographic operations
✓ Complex calculations
✓ Compression/decompression
✓ Syntax highlighting
Not for Workers:
✗ DOM manipulation
✗ Simple calculations
✗ Tasks requiring window/document
✗ Short-lived operations
Limitations
Conclusion
Web Workers enable true parallelism in JavaScript. Use them for computationally intensive tasks to keep your UI responsive.
The key is identifying operations that don't need DOM access and can benefit from parallel execution.