YAML Tools

Format messy or minified YAML into clean, consistently indented output. Comments are preserved.

Paste your YAML and instantly see if it's valid. Invalid YAML shows a clear error message from js-yaml's parser.

Diff two YAML configs side-by-side or unified. Ignores formatting noise — only real semantic changes are flagged.

Check compose files for missing services, services without image/build, and malformed sections — before docker compose up fails.

Check Kubernetes manifests for missing apiVersion/kind/metadata and unknown kinds — a fast structural sanity check before kubectl apply.

Format messy or minified YAML into clean, consistently indented output. Comments are preserved.

Paste your YAML and instantly see if it's valid. Invalid YAML shows a clear error message from js-yaml's parser.

Diff two YAML configs side-by-side or unified. Ignores formatting noise — only real semantic changes are flagged.

Catch YAML problems fast: syntax errors, duplicate keys, tab indentation, and trailing whitespace — with line numbers for every issue.

Validate YAML documents against a JSON Schema (written in JSON or YAML) with detailed per-path errors — powered by AJV locally.

Detect yes/no/on/off, octal 0123, and similar tokens that change meaning between YAML 1.1 and 1.2 — the classic config footguns.

Parse YAML text and produce equivalent JSON using the js-yaml library. Works with any valid YAML 1.2 document.

Convert JSON into equivalent YAML 1.2 syntax for Kubernetes manifests, Docker Compose, or any config that prefers YAML. Configurable indent and flow style; runs entirely in your browser.

Convert YAML to TOML or TOML to YAML — for moving configs between projects that standardized on the other format. Fully client-side.

Convert YAML into XML with a configurable root element — useful for SOAP, feeds, and legacy systems that still speak XML.

Turn a YAML list of maps into CSV — keys become headers, nested values stringify, and cells escape per RFC 4180.

Turn CSV with a header row into a YAML list of mappings — handy for converting spreadsheet exports into config-style data.

Flatten a YAML config into dotenv-style KEY=VALUE lines, with nested keys joined by double underscores (DATABASE__HOST=localhost).

Turn dotenv KEY=VALUE lines into nested YAML, rebuilding objects and arrays from double-underscore keys (DATABASE__PORT=5432).

Check Kubernetes manifests for missing apiVersion/kind/metadata and unknown kinds — a fast structural sanity check before kubectl apply.

Check compose files for missing services, services without image/build, and malformed sections — before docker compose up fails.

Check workflow files for the required 'on' trigger, jobs, and steps that each have 'uses' or 'run' — a quick structural sanity check.

Check .gitlab-ci.yml for jobs missing 'script', reserved-key misuse, and YAML errors — before your pipeline fails at the first job.

Check playbooks are a list of plays with hosts and named tasks — a fast structural check before ansible-playbook runs.

Paste base values and overrides separated by --- to produce the merged result the way Helm does — deep merge with later docs winning.

Expand every &anchor and *alias in a YAML file into standalone output, with a breakdown of each anchor's definition and usage lines.

Combine several YAML documents (separated by ---) into a single merged document — nested maps merge, later values win.

Split a file containing several YAML documents separated by --- into individual documents you can view and download separately.

Extract values from YAML with yq-style dot paths (a.b[1].c) — like jq for YAML, without installing anything.

Strip # comments from YAML — including trailing comments — while leaving hashes inside quoted strings completely untouched.

Convert compact flow-style YAML ({a: 1, b: [1, 2]}) into the indented block style most config files use — with nothing uploaded.

Convert YAML to TOML or TOML to YAML — for moving configs between projects that standardized on the other format. Fully client-side.

Validate YAML documents against a JSON Schema (written in JSON or YAML) with detailed per-path errors — powered by AJV locally.

Check Kubernetes manifests for missing apiVersion/kind/metadata and unknown kinds — a fast structural sanity check before kubectl apply.

Check compose files for missing services, services without image/build, and malformed sections — before docker compose up fails.

Expand every &anchor and *alias in a YAML file into standalone output, with a breakdown of each anchor's definition and usage lines.

Paste base values and overrides separated by --- to produce the merged result the way Helm does — deep merge with later docs winning.

Catch YAML problems fast: syntax errors, duplicate keys, tab indentation, and trailing whitespace — with line numbers for every issue.

Convert YAML into XML with a configurable root element — useful for SOAP, feeds, and legacy systems that still speak XML.

Combine several YAML documents (separated by ---) into a single merged document — nested maps merge, later values win.

Flatten a YAML config into dotenv-style KEY=VALUE lines, with nested keys joined by double underscores (DATABASE__HOST=localhost).

Turn dotenv KEY=VALUE lines into nested YAML, rebuilding objects and arrays from double-underscore keys (DATABASE__PORT=5432).

Check workflow files for the required 'on' trigger, jobs, and steps that each have 'uses' or 'run' — a quick structural sanity check.

Check .gitlab-ci.yml for jobs missing 'script', reserved-key misuse, and YAML errors — before your pipeline fails at the first job.

Split a file containing several YAML documents separated by --- into individual documents you can view and download separately.

Extract values from YAML with yq-style dot paths (a.b[1].c) — like jq for YAML, without installing anything.

Strip # comments from YAML — including trailing comments — while leaving hashes inside quoted strings completely untouched.

Convert compact flow-style YAML ({a: 1, b: [1, 2]}) into the indented block style most config files use — with nothing uploaded.

Detect yes/no/on/off, octal 0123, and similar tokens that change meaning between YAML 1.1 and 1.2 — the classic config footguns.

Check playbooks are a list of plays with hosts and named tasks — a fast structural check before ansible-playbook runs.

Turn a YAML list of maps into CSV — keys become headers, nested values stringify, and cells escape per RFC 4180.

Turn CSV with a header row into a YAML list of mappings — handy for converting spreadsheet exports into config-style data.

Format messy or minified YAML into clean, consistently indented output. Comments are preserved.

Paste your YAML and instantly see if it's valid. Invalid YAML shows a clear error message from js-yaml's parser.

Diff two YAML configs side-by-side or unified. Ignores formatting noise — only real semantic changes are flagged.

Parse YAML text and produce equivalent JSON using the js-yaml library. Works with any valid YAML 1.2 document.

Convert JSON into equivalent YAML 1.2 syntax for Kubernetes manifests, Docker Compose, or any config that prefers YAML. Configurable indent and flow style; runs entirely in your browser.