Format Dockerfile Online — Instruction Normalizer

Normalize Dockerfile instruction casing and spacing with dockerfile-utils — browser-local formatting.

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Dockerfile formatter — instruction normalization
Turn lowercase or inconsistent Dockerfiles into readable, review-friendly instructions before opening a PR or sharing in docs.

Developer notes

• Uses dockerfile-utils for instruction casing and spacing. • Auto-format on paste/upload/sample; manual edits use the Format button (⌘↵). • Not a substitute for Hadolint best-practice linting — use lint-dockerfile. • Processing stays in the browser (dockerfile-utils loads on demand).

When teams pick this route

• Normalize Dockerfiles copied from blog posts (often lowercase). • Prepare a Dockerfile snippet for internal style guides. • Quick format before lint-dockerfile for DL rules. • Clean up hand-edited multi-stage files.

Worked examples

Lowercase instructions from a tutorial

Before

from node:20-alpine workdir /app copy package*.json ./ run npm ci --omit=dev copy . . expose 3000 cmd ["npm", "start"]

After format

FROM node:20-alpine WORKDIR /app COPY package*.json ./ RUN npm ci --omit=dev COPY . . EXPOSE 3000 CMD ["npm", "start"]

Multi-stage build skeleton

Before

from golang:1.22 AS build workdir /src copy go.mod go.sum ./ run go build -o /bin/api ./cmd/api from gcr.io/distroless/base COPY --from=build /bin/api /api entrypoint ["/api"]

After format

FROM golang:1.22 AS build WORKDIR /src COPY go.mod go.sum ./ RUN go build -o /bin/api ./cmd/api FROM gcr.io/distroless/base COPY --from=build /bin/api /api ENTRYPOINT ["/api"]

Navigate related DevOps tools

Run lint Dockerfile for DL rules, or open the DevOps hub.

Dockerfile formatter FAQ

Layout and casing

Same as hadolint?

No — this tool formats layout and casing. Use lint-dockerfile for best-practice DL rules.

Does it fix JSON CMD form?

It normalizes keywords; switch shell-form CMD to JSON manually or via lint suggestions.

Multi-stage builds?

Yes — each stage is formatted in place.

DevOps & Infra

Terraform HCL format/validate/minify, Dockerfile format & lint, Docker Compose and .env validation.

Explore other tool categories

Minify

Shrink code and assets for production — minify JavaScript, CSS, HTML, JSON and XML before gzip or CDN deploy.

Beautify

Make code readable with consistent indentation — beautify JavaScript, CSS, TypeScript, SCSS, LESS, Markdown, GraphQL, SQL, YAML and more in your browser.

Unminify

Expand minified or compressed code — unminify JavaScript, CSS, TypeScript, SCSS, LESS, SQL, YAML and other formats when debugging or reviewing.

Conversion

Transform data between JSON, YAML, XML and CSV locally — no server uploads.

CSS preprocessors

Compile SCSS or LESS to standard CSS in the browser — pair with beautify or minify for a full stylesheet workflow.

JSON Tools

Validate, format, diff and explore JSON payloads — complementary to minifiers and converters.

SVG Tools

Preview, optimize with SVGO, export Data URI, resize, beautify, convert to JSX and validate SVG — all in your browser.

CI/CD

GitHub Actions and GitLab CI — format YAML and check workflow/job structure in your browser.

Logs & observability

Line-oriented JSON/NDJSON and Nginx/Apache access logs — format, filter, validate, and CSV/TSV.

Kubernetes

Multi-doc manifests, structural validate, Ingress/Deployment starters, and Helm values formatting.

Networking / IP

CIDR, subnets, and IPv4/IPv6 helpers — in your browser.

Security & tokens

JWKS, X.509 certificates, and secrets scan — browser-local.

API & schemas

OpenAPI tools to format, validate, and lint your specs.

Encoding

Encode or decode Base64, URL components and HTML entities — client-side only.

Developer utilities

Timestamps, UUID, ULID, Nanoid, cron, passwords, regex, slugify, number bases, case, text diff, and chmod — all client-side.

Text & Markdown

Count words, build Markdown TOCs, and clean line lists — all in your browser.

AI & LLM

Token counting, pricing estimates, and context-window fit — 100% browser-local.

Serialization

Serialize and deserialize PHP data structures beside JSON workflows.