When should I NOT use worker threads in Node.js?
For I/O-bound work. Async APIs (fs.readFile, fetch, database queries) already keep the event loop free. Using worker threads for I/O adds overhead without benefit, since the I/O is delegated to libuv anyway.
Verify This Answer
Cross-check this information using these trusted sources:
More FAQs in How to Use Worker Threads in Node.js for CPU-Heavy Work
Import { Worker } from 'worker_threads', create a new Worker with a file path, communicate via postMessage and on('message'), handle errors with the 'error' event, and use SharedArrayBuffer for zero-copy large data sharing.
For heavy CPU computation: image processing, cryptographic computation, large data processing, machine learning inference. Anything that takes more than a few milliseconds of synchronous CPU time should be offloaded to keep the event loop free.
Use postMessage to send data, which copies it by default. For large data, use SharedArrayBuffer for zero-copy sharing between the main thread and workers, which avoids the overhead of copying.
Still have questions?
Browse all our FAQs or reach out to our support team