What does output: standalone do?

Next.js traces the files the server needs and writes a minimal server.js plus those files to .next/standalone. The runtime image does not need a full node_modules install. You still copy public and .next/static yourself.

The dependency and build stages can hold the compiler and the package cache. Docker ships only the last stage, so the production image stays smaller.

Should I use alpine or slim?

Slim is the safer default. It uses glibc, which matches sharp and most Prisma engines. Alpine is smaller and uses musl. On Alpine, set Prisma binaryTargets to a linux-musl target or the query engine will be missing.

How do NEXT_PUBLIC_ env vars work in Docker?

Next.js inlines NEXT_PUBLIC_ values at build time, so pass them as build args. Server-only secrets are read at runtime. Do not put those secrets in ARG.

A non-root user limits the damage if the app is compromised. The image creates a nextjs user and gives that user ownership of the app files so the runtime cache can be written.

Does it work with Coolify, Railway, or Fly?

Yes. Any Docker host can run the image. Expose port 3000, pass runtime env on the platform, and pass NEXT_PUBLIC_ values at build time.

Next.js Dockerfile generator

Generate a production multi-stage Dockerfile for Next.js, plus .dockerignore and compose.

In Package manager, Node version, base image, standalone, Prisma, healthcheck, port, and build-time env names./Out Dockerfile, .dockerignore, docker-compose.yml, a next.config snippet, and build commands. A zip of the files.

Runs locally

Package manager

Node

Base

Standalone outputPrismaprisma migrate deployHealthcheckDisable telemetryBuildKit cache mountsMonorepo note

Port

Health path

Build-time NEXT_PUBLIC_ names

Comma-separated. They become ARG lines. Server secrets stay runtime env.

Estimated image size

about 220–280 MB

A static estimate, not a measurement.

Dockerfile

1FROM node:22-bookworm-slim AS deps

2WORKDIR /app

3RUN corepack enable

4ENV NEXT_TELEMETRY_DISABLED=1

5COPY package.json pnpm-lock.yaml* package-lock.json* yarn.lock* bun.lock* ./

6RUN --mount=type=cache,target=/pnpm/store pnpm install --frozen-lockfile

8FROM node:22-bookworm-slim AS builder

9WORKDIR /app

10RUN corepack enable

11ENV NEXT_TELEMETRY_DISABLED=1

12COPY --from=deps /app/node_modules ./node_modules

13COPY . .

15RUN pnpm build

17FROM node:22-bookworm-slim AS runner

18WORKDIR /app

19ENV NODE_ENV=production

20ENV NEXT_TELEMETRY_DISABLED=1

21ENV PORT=3000

22ENV HOSTNAME=0.0.0.0

23RUN addgroup --system --gid 1001 nodejs && adduser --system --uid 1001 nextjs

24COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./

25COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static

26COPY --from=builder --chown=nextjs:nodejs /app/public ./public

27HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \

28 CMD node -e "fetch('http://127.0.0.1:3000/api/health').then((res) => process.exit(res.ok ? 0 : 1)).catch(() => process.exit(1))"

29USER nextjs

30EXPOSE 3000

31CMD ["node", "server.js"]

How to use it

1Pick a package manager and Node versionChoose npm, pnpm, yarn, or bun, then Node 20, 22, or 24 on Alpine or Debian slim.
2Toggle standalone, Prisma, and the healthcheckStandalone is on by default. Prisma adds prisma generate. The healthcheck calls a route with node fetch, so the image does not need curl.
3Copy the files and run docker buildDownload the Dockerfile, ignore file, and compose file, set output standalone in next.config, then build and run.