How do I debug Node.js applications?
node-inspector could save the day! Use it from any browser supporting WebSocket. Breakpoints, profiler, livecoding, etc... It is really awesome.
Install it with:
npm install -g node-inspectorThen run:
node-debug app.js
Debugging
Profiling
node --prof ./app.jsnode --prof-process ./the-generated-log-file
Heapdumps
Flamegraphs
- 0x
- jam3/devtool then Chrome Developer Tools Flame Charts
- Dtrace and StackVis — Only supported on SmartOS
- clinicjs
Tracing
Logging
Libraries that output debugging information
Libraries that enhance stack trace information
Benchmarking
- Apache Bench:
ab -n 100000 -c 1 http://127.0.0.1:9778/ - wrk
Other
Legacy
These use to work but are no longer maintained or no longer applicable to modern node versions.
- https://github.com/bnoordhuis/node-profiler - replaced by built-in debugging
- https://github.com/c4milo/node-webkit-agent - replaced by node inspector
- https://nodetime.com/ - defunct
The V8 debugger released as part of the Google Chrome Developer Tools can be used to debug Node.js scripts. A detailed explanation of how this works can be found in the Node.js GitHub wiki.