yarn install --production: skip devDependencies (Yarn 1 and Yarn 4)

yarn install --production installs only dependencies and skips devDependencies, the Yarn 1 (Classic) way to build a lean node_modules for a server or a Docker image. Yarn 1 also switches to it automatically when NODE_ENV=production; --production=false forces the full install. Yarn 2 and later do not have the flag: there, yarn workspaces focus --production does the same job.

Yarn 1: with and without the flag

cat > package.json <<'EOF'
{
  "name": "demo",
  "version": "1.0.0",
  "license": "MIT",
  "dependencies": { "is-number": "7.0.0" },
  "devDependencies": { "is-odd": "3.0.1" }
}
EOF
npx --yes yarn@1 install --silent >/dev/null 2>&1
echo "--- yarn install"
ls node_modules
rm -rf node_modules
npx --yes yarn@1 install --production --frozen-lockfile --silent >/dev/null 2>&1
echo "--- yarn install --production --frozen-lockfile"
ls node_modules
rm -rf node_modules
NODE_ENV=production npx --yes yarn@1 install --frozen-lockfile --silent >/dev/null 2>&1
echo "--- NODE_ENV=production"
ls node_modules

--- yarn install
is-number
is-odd
--- yarn install --production --frozen-lockfile
is-number
--- NODE_ENV=production
is-number

The dev dependency is-odd is installed only by the plain yarn install. The lockfile written by the first run is reused unchanged by the frozen installs.

Yarn 1 and Yarn 4 equivalents

yarn workspaces focus is part of Yarn 4 itself; in Yarn 2 and 3 it comes from the workspace-tools plugin (yarn plugin import workspace-tools). The full Classic versus Berry comparison is in Yarn classic vs Yarn Berry.

Dockerfile (Yarn 1)

FROM node:24-slim
WORKDIR /app
COPY package.json yarn.lock ./
RUN yarn install --production --frozen-lockfile && yarn cache clean
COPY . .
CMD ["node", "server.js"]

yarn cache clean keeps the global cache out of the image layer.

Pitfalls

• When the image also builds the app, install everything first, build, then reinstall with --production in a new stage; build tools such as TypeScript live in devDependencies.
• A runtime dependency listed under devDependencies only fails in production, as Cannot find module. Move it with yarn add pkg.
• NODE_ENV=production exported for the whole CI job makes Yarn 1 skip test tools; tests then fail to start. Set it only for the production install.
• yarn install --production with Yarn 4 is an unknown option error, not a silent no-op; check yarn --version when copying old scripts.

npm and pnpm call the same idea npm install --omit=dev and pnpm install --prod: see npm install --omit=dev and pnpm install --prod.

FAQ