In many cases, we want to debug a process from initialization, or we may want to set up breakpoints before anything can happen.

From Node 8 onwards, we use the following to start Node in an immediately paused state:

$ node --inspect-brk index.js

In Node 6 (at time of writing, 6.10.0), --inspect is supported but --inspect-brk isn't. Instead, we can use the legacy --debug-brk flag in conjunction with --inspect like so:

$ node --debug-brk --inspect index.js

In Node v4 and lower, we'd simply use --debug-brk instead of --debug (in conjunction with another client, see Using Node Inspector with older Node versions)