How to fix npm ERR! code EVERSIONMISMATCH npm ERR! Dependency version mismatch in npm

Bypass strict peer dependency resolution:

npm install --legacy-peer-deps

This reverts to npm 6's behavior where conflicts are warnings, not errors. It's a quick fix but may hide real compatibility issues.

To make it permanent (not recommended for all projects):

npm config set legacy-peer-deps true

Read the error message carefully. It shows exactly what conflicts:

npm ERR! ERESOLVE could not resolve
npm ERR! Found: [email protected]
npm ERR! peer react@"^18.0.0" from [email protected]

This tells you react-dom@18 needs React 18, but you have React 17.

Upgrade packages to versions that work together:

# Check available versions
npm view react-dom versions

# Update to compatible versions
npm install react@18 react-dom@18

Or downgrade the newer package:

npm install react-dom@17

Sometimes stale dependencies cause conflicts:

rm -rf node_modules package-lock.json
npm cache clean --force
npm install

This resolves dependencies fresh without cached decisions.

Force specific versions for nested dependencies (npm 8.3+):

{
  "overrides": {
    "lodash": "4.17.21"
  }
}

This tells npm to use lodash 4.17.21 everywhere, regardless of what individual packages request.

Caution: This may cause runtime issues if packages truly need different versions.

Force installation ignoring all conflicts:

npm install --force

Warning: This can create broken installations. Only use for debugging or when you're certain the conflicts don't matter.