Skip to main content

json-yaml

A JSON to YAML and YAML to JSON converter translates between the two most common human-readable structured-data formats — JSON (concise, brace-delimited, programmer-friendly) and YAML (indentation-based, more human-readable, used heavily in configuration). The ZTools JSON/YAML Converter handles either direction, validates input before converting, preserves types (numbers stay numbers, booleans stay booleans), supports YAML-specific features (anchors, aliases, multi-line strings) when converting from JSON, and lets you pick indentation (2 or 4 spaces) for consistent output.

Use cases​

Switching config formats between projects​

GitHub Actions uses YAML; older CI tools use JSON. Convert your existing config when migrating between systems.

Reading API responses in YAML​

JSON API responses are dense and hard to scan. Convert to YAML for code reviews and incident postmortems — easier to read.

Authoring Kubernetes configs in JSON, deploying as YAML​

JSON has better tooling support for generation; YAML is the kubectl-friendly format. Author in JSON, convert at deploy time.

OpenAPI / Swagger spec translation​

OpenAPI specs work in both formats. Some teams prefer YAML for authoring; others prefer JSON for diffs. Convert to whichever the team uses.

How it works​

  1. Pick the direction — JSON → YAML or YAML → JSON. The same input field accepts either; auto-detect determines which.
  2. Paste your data — Validates first. Malformed JSON or YAML produces an error with line and column info before conversion.
  3. Configure output format — YAML output: indentation (2 or 4 spaces), flow style (compact inline) vs block style (one item per line), explicit document marker (---). JSON output: pretty-printed (default 2-space) or minified.
  4. Read the converted output — Side-by-side preview shows source vs converted. One-click copy or download.

Examples​

Input: JSON: {"name":"Alice","tags":["admin","user"]}

Output: YAML: name: Alice tags:

  • admin
  • user

Input: YAML: a: 1 b: 2

Output: JSON: {"a":1,"b":2}

Input: YAML with anchor: defaults: &d retries: 3 prod: *d

Output: JSON: {"defaults":{"retries":3},"prod":{"retries":3}}

Frequently asked questions​

When should I use JSON vs YAML?

JSON: programmatic data, API requests/responses, machine-to-machine. Pros: simpler spec, faster parsing, no indentation gotchas. YAML: human-authored config files (Kubernetes, CI, OpenAPI). Pros: readable, supports comments, less punctuation noise.

Can YAML express things JSON can't?

Yes: comments, anchors and aliases (DRY references), multi-line strings with literal/folded operators, tagged types (e.g., !!int "123"). Converting YAML → JSON loses these — anchors are expanded; comments are dropped.

What about JSON things YAML can't do?

YAML 1.2 is a superset of JSON in practice — anything valid in JSON is valid YAML. Converting JSON → YAML is always safe; the reverse may lose YAML-specific features.

How are dates handled?

JSON has no date type — dates are typically ISO strings. YAML 1.2 supports timestamps natively but they're commonly written as strings too. The converter preserves string form by default.

How is duplicate-key handling?

Both formats technically reject duplicate keys, though many parsers accept them silently. The converter validates and warns; if a YAML input has duplicates, the JSON output will have only the last value (overwrite behavior).

Tips​

  • Use JSON for machine-to-machine; YAML for human-edited config.
  • YAML's strict-indentation rule means small whitespace mistakes break parsing — validate before conversion.
  • When converting YAML to JSON, comments are lost — keep your YAML version if comments are important.
  • For consistent output, pick a single style (block vs flow YAML) per project rather than mixing.

Try it now​

The full json-yaml runs in your browser at https://ztools.zaions.com/json-yaml — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub