Cypress baseUrl "ECONNREFUSED" - Server Not Running in CI

By Kaveh Alemi·Latchkey

Cypress probed your baseUrl and the connection was refused. The app server was never started in CI, is still booting, or baseUrl points where nothing is listening.

What this error means

Cypress aborts at startup with "Cypress could not verify that this server is running" and retries the URL before giving up with ECONNREFUSED. Specs never run because the app is unreachable.

Cypress could not verify that this server is running:

  > http://localhost:3000

We are verifying this server because it has been configured as your
baseUrl. ... connect ECONNREFUSED 127.0.0.1:3000

Common causes

App server not started before Cypress

The CI step ran cypress run without first starting (and waiting for) the dev/preview server, so nothing answers at baseUrl.

Server still booting (race)

The app was launched in the background but Cypress probed before it finished compiling/listening - a timing race that often clears on retry.

Wrong baseUrl or port

baseUrl does not match where the app listens (wrong port, 127.0.0.1 vs localhost, or a container hostname).

How to fix it

Start the server and wait for it

Use start-server-and-test (or wait-on) so Cypress runs only once the URL responds.

npx start-server-and-test 'npm start' http://localhost:3000 'cypress run'

Verify baseUrl matches the server

// cypress.config.js
module.exports = { e2e: { baseUrl: 'http://localhost:3000' } };

How to prevent it

• Always gate cypress run behind start-server-and-test/wait-on.
• Keep baseUrl and the server port in one shared config value.
• Give the server a generous readiness timeout on slow CI.

Frequently asked questions

Related guides

References

• GitHub Actions documentation