Version mismatch errors occur when npm cannot resolve conflicting version requirements across your project dependencies. Use --legacy-peer-deps flag or update packages to compatible versions.
Version mismatch errors occur when npm cannot resolve conflicting version requirements across your project dependencies. This happens when two or more packages in your dependency tree require incompatible versions of the same library—for example, Package A needs React 16 while Package B needs React 18. Starting with npm v7, npm strictly enforces these conflicts and will fail installation rather than silently installing conflicting versions. The error indicates a breakdown in dependency resolution, preventing npm from installing a consistent set of packages.
Start with a clean slate by removing cached packages and reinstalling:
# Remove node_modules and lockfile
rm -rf node_modules
rm package-lock.json
# Clear npm cache
npm cache clean --force
# Reinstall all dependencies
npm installVersion mismatches often occur after updating Node.js. Verify your current version and match it to your project requirements:
node --version
npm --versionIf using nvm, check your .nvmrc file and switch to the correct version:
# With nvm, this auto-switches if .nvmrc exists
nvm use
# Or specify explicitly
nvm install 18.17.0
nvm use 18.17.0For npm v7+, add the --legacy-peer-deps flag to bypass strict peer dependency checking:
npm install --legacy-peer-depsOr make it permanent for your project by creating .npmrc:
echo 'legacy-peer-deps=true' > .npmrc
npm installWarning: This bypasses safety checks. Only use temporarily while resolving root causes.
Identify which packages are conflicting by examining the error output, then update them:
# First, identify conflicts
npm ls
# Check available versions of a package
npm view react versions
# Update to a compatible version
npm install [email protected]
npm install [email protected]In monorepo setups, ensure all workspaces use consistent dependency versions:
# Check current workspace structure
npm ls --workspaces
# Install with workspace awareness
npm install --workspace-rootEdit your root package.json and individual workspace package.json files to use identical version ranges for shared dependencies.
If nothing else works, force npm to ignore all conflicts (use cautiously):
npm install --forceThis is the most dangerous option as packages may not work correctly together. Use only when you understand the specific conflicts and have tested the result.
Understanding npm's resolution algorithm is key: npm v7+ uses a more restrictive resolution that will fail if peer dependencies cannot be satisfied, while npm v6 would only warn. In monorepo environments, npm installs shared dependencies at the root level if versions match, but creates separate node_modules in individual workspaces if versions differ. For native modules like sqlite3 or bcrypt, version mismatches occur because the module is compiled for a specific Node.js version's ABI; switching Node versions requires recompilation via npm rebuild.
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npm ERR! code EMPTYPACKAGE npm ERR! Package contains no files
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npm ERR! code EADDRNOTAVAIL npm ERR! errno EADDRNOTAVAIL npm ERR! Address not available
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