nightwatch connection refused to selenium server: how to fix

TL;DR

Nightwatch talks to a Selenium server that is not running. Start the server (or use direct driver mode), match the host and port in config, and verify with curl.

Error

Error: Connection refused to selenium server at YOUR_HOST:4444

Steps

1. Check if anything listens: curl YOUR_HOST/status. Expected: 200 means it is up and the config is wrong.
2. Start the server: java -jar selenium-server.jar standalone or let Nightwatch manage it. Expected: the status endpoint responds.
3. Match selenium.host and selenium.port in nightwatch.conf.js to reality. Expected: config equals the server.
4. Consider direct driver mode (webdriver with chromedriver) to skip the server entirely. Expected: simpler setup, fewer moving parts.
5. Re-run. Expected: Nightwatch connects.

When to use

• Connection refused to the Selenium server at startup.
• Server-based (not direct) setups.

When not to use

• Assertion failures in running tests.
• Direct driver mode issues.

Tool compatibility

• Nightwatch 2.x/3.x; Selenium server 4.x.

Variant phrasings

Nightwatch ECONNREFUSED the loopback address:4444

The same failure in Node terms.

Selenium server not running for Nightwatch

Start it or switch to direct mode.

Why it happens

Nightwatch is a client; without a server there is nothing to talk to. Config drift between the two is the usual cause.

Edge cases

• Java version matters for the server jar; check compatibility.
• Grid URLs differ from standalone; use the right path.
• Direct mode removes the server but needs the driver binary managed.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_VBfjFxOPM0A-IEO3FBvgxw