Loading converter...

JSON to YAML Converter Online 2026 - Fast, Secure & Private

Convert JSON to YAML for configuration files and Kubernetes manifests. 100% client-side privacy. Free online tool.

Key Features

  • Indentation-based output
  • Comment preservation
  • Schema validation
  • Kubernetes-ready YAML

How to Use

  1. Paste your JSON data
  2. Configure indentation preference (2 or 4 spaces)
  3. Click Convert to generate YAML
  4. Review the indentation-based structure
  5. Verify list and object formatting
  6. Copy or download the YAML
  7. Use in your configuration management system
  8. Validate YAML syntax with validator if needed

Expert FAQ

  • My JSON has a string value "no" for a country-code field — will it survive as a string in the YAML output?
    Yes, this converter explicitly quotes it ("no") in the output specifically to prevent what's known as "the Norway problem": YAML 1.1 (which many parsers, including older PyYAML defaults, still implement) treats unquoted no, yes, on, off, true, false, y, and n as booleans. A country-code list containing Norway (NO) silently becomes a boolean in naive converters. Since the source value is a JSON string, this tool always emits it quoted to guarantee it round-trips as a string in any YAML 1.1 or 1.2 parser.
  • Does a JSON key like "012345" or a numeric string with a leading zero need special handling in YAML?
    Yes — under YAML 1.1, an unquoted scalar like 0123 can be interpreted as an octal number by some parsers. Since the source is a JSON string (JSON itself doesn't allow leading zeros in actual numbers), this converter quotes any string value that looks like it could be misread as a number, octal, or boolean by a strict YAML 1.1 parser, trading a little extra output verbosity for guaranteed round-trip fidelity.
  • What happens to JSON's null value?
    It converts to YAML's null, which can be written as null, Null, NULL, or the tilde (~) — this tool uses the explicit "null" keyword rather than the bare tilde, since it's the least ambiguous to a human skimming the generated config (Kubernetes manifests and Helm charts both commonly use this convention).
  • Will multi-line JSON string values (e.g. a description field with embedded newlines) come out readable?
    Yes — rather than emitting a single-line string with literal \n escape sequences (which technically round-trips correctly but is hard to read in a config file), values containing newlines are converted to YAML's block scalar syntax (using | for literal blocks), so a long description reads as natural multi-line text in the output instead of an escaped one-liner.

Technical Details

Converting JSON to YAML is more than swapping braces for indentation — YAML's broader (and looser) scalar-typing rules mean a handful of JSON string values need deliberate quoting to survive the round trip unchanged. The best-known case is "the Norway problem": YAML 1.1 treats bare yes/no/on/off/true/false (case-insensitively, in several spellings) as booleans, so a country-code value of "NO" would silently become the boolean false in a naive converter. Since JSON's type system is explicit (a JSON string is unambiguously a string), this converter quotes any output scalar that YAML's looser grammar could otherwise misinterpret as a boolean, null, octal/hex number, or timestamp. Structurally, JSON objects become YAML mappings (indented key: value blocks) and JSON arrays become YAML sequences (- item lists); nesting depth maps directly, with indentation replacing JSON's braces and brackets. Multi-line string values are emitted using YAML's block scalar syntax rather than escaped single-line strings, since the generated file is usually meant to be hand-edited afterward (Kubernetes manifests, GitHub Actions workflows, Ansible playbooks) and escaped newlines defeat that purpose. One direction this conversion doesn't need to worry about: YAML-only features like anchors/aliases (&ref / *ref) and comments have no JSON equivalent, so there's nothing to lose going JSON → YAML — those concerns only matter for the reverse direction (YAML to JSON), where anchors get resolved/expanded and comments are necessarily dropped. After generating your config, run it through the YAML Validator to confirm a strict parser accepts it exactly as intended.