5 Free Browser-Based Dev Tools: GraphQL Formatter, Docker Compose Validator, Dockerfile Linter, and More

I just shipped 5 new tools to DevNestio — a hub of 172 free, browser-only developer utilities. All tools are zero-signup, zero-upload, and work offline. 1. GraphQL Query Formatter & Minifier https://devnestio.pages.dev/graphql-formatter/ Paste any GraphQL operation and get: Pretty-print — consistent indentation Minify — strips comments and whitespace for smaller request payloads Validation — brace/parenthesis balance check Operation detection — lists all named query , mutation , subscription , fragment Useful for quick query cleanup before pasting into code reviews or API docs. 2. Protobuf (.proto) Formatter & Validator https://devnestio.pages.dev/protobuf-formatter/ Online formatter and validator for Protocol Buffer .proto files: Duplicate field number detection Message and enum structure validation Syntax-highlighted output One-click copy Great for a sanity check before pushing .proto changes in a gRPC service. 3. Docker Compose Validator https://devnestio.pages.dev/docker-compose-validator/ Paste your docker-compose.yml to catch: Missing services section Services without image or build Invalid port mappings ( 80:80 , 127.0.0.1:8080:80 , 53:53/udp , ranges…) depends_on referencing non-existent services Circular dependency detection (A→B→A) Unknown restart policies # This will flag errors: services : web : ports : - " abc:xyz" # invalid port depends_on : - missing_service # unknown service 4. Dockerfile Analyzer & Linter https://devnestio.pages.dev/dockerfile-analyzer/ Analyzes your Dockerfile for best practice violations across three categories: Security sudo usage inside RUN Container running as root (no USER instruction) Secrets baked into ENV / ARG (password, secret, token, key) Image size :latest base image tag apt-get update in a separate RUN (stale cache risk) apt-get install without --no-install-recommends apt cache not cleaned ( rm -rf /var/lib/apt/lists/* ) ADD used for local files instead of COPY Layer optimization Consecutive RUN instructions (suggest c