YAML ⇄ JSON Converter
Convert config files both ways, with proper handling of nested structure, flow collections, and quoting.
Also known as: YAML to JSON converter, JSON to YAML converter, YAML/JSON converter
How it works
- 1Choose YAML → JSON or JSON → YAML.
- 2Paste your YAML or JSON, or click Try a sample.
- 3Review the converted output.
- 4Copy or download the result.
Why use YAML ⇄ JSON Converter
Handles real-world YAML
Nested mappings and sequences, flow-style collections, quoted strings, and comments are all supported.
Correct re-quoting on output
Strings like "true" or "42" are automatically re-quoted when converting JSON to YAML, so their meaning isn't silently changed.
Checked against a trusted YAML library
Parsing behavior was cross-verified against js-yaml during development, not trusted on faith.
Round-trip verified
JSON → YAML → JSON round trips were tested to confirm values come back unchanged.
Both directions, one tool
No need for separate tools depending on which way you're converting.
Nothing uploaded
Config files often contain sensitive details — conversion happens entirely in your browser.
Who uses YAML ⇄ JSON Converter
Converting a Kubernetes or Docker Compose file to JSON
Turn a YAML manifest into JSON for use with tools or scripts that expect JSON input.
Generating a YAML config from JSON data
Convert a JSON object into clean, properly formatted YAML for a config file.
Debugging a CI/CD pipeline file
Convert a GitHub Actions or GitLab CI YAML file to JSON to inspect its exact structure.
Migrating configuration between formats
Move settings between a YAML-based tool and a JSON-based one in either direction.
Learning YAML syntax
Write familiar JSON and convert it to YAML to see the equivalent syntax side by side.
Validating YAML structure
Convert to JSON to clearly see the actual nested structure a YAML file represents.
About YAML ⇄ JSON Converter
YAML looks deceptively simple — it's the format behind Docker Compose files, Kubernetes manifests, GitHub Actions workflows, and countless application configs — but its actual specification is famously large and full of subtle edge cases (implicit typing, block vs. flow style, multiple ways to quote a string). This tool implements the common subset that covers the overwhelming majority of real-world YAML: block and flow mappings, block and flow sequences, quoted and unquoted scalars, comments, and standard type coercion for numbers, booleans, and null.
Converting JSON to YAML is the direction where correctness quietly matters most: a string like "true", "42", or one containing a colon needs to be re-quoted on output, or it would silently be read back as a boolean, a number, or a broken mapping instead of the original string. This tool's YAML writer handles that quoting correctly, verified with round-trip tests (JSON → YAML → JSON) confirming the original value always comes back unchanged.
Every YAML parsing decision in this tool was checked against js-yaml — a mature, widely-used YAML library — as a correctness oracle during development: nested mappings, sequences of objects, flow collections, quoted strings with escapes, comments, and numeric edge cases were all cross-checked to produce identical results before this tool was ever wired into a UI, rather than trusting a hand-written parser on faith.
Both directions run entirely in your browser. Config files often encode real infrastructure details — service names, environment variables, internal hostnames — so keeping conversion local rather than sending that to a server is a meaningful privacy difference, not just a technical preference.
YAML ⇄ JSON Converter vs. other options
How Open Tools Library compares to desktop software and other online tools.
| Feature | Open Tools Library | Desktop software | Other online tools |
|---|---|---|---|
| Price | Free, unlimited | Often paid IDE plugins | Often free with upload required |
| Config file privacy | Never leaves your device | Stays local | Uploaded to a server |
| Nested structure support | Full support | Varies | Often breaks on nesting |
| Correct re-quoting on output | Yes, automatic | Varies | Often missing, causing silent bugs |
| Both directions | YAML↔JSON in one tool | Often separate tools | Often separate tools |
| Installation | None | Required | None |
Pro tips
- YAML is indentation-sensitive — inconsistent indentation is the most common cause of a parse error, since it changes what's nested under what.
- Flow-style collections ([1, 2, 3] or {a: 1, b: 2}) are supported inline, alongside the more common block style.
- When converting JSON to YAML, strings that look like numbers, booleans, or null are automatically quoted so they're read back correctly as strings.
- This covers the common YAML subset used in most real-world config files — advanced features like anchors/aliases (&ref, *ref) and multi-document files aren't supported.
Technical specs
- YAML features supported
- Block & flow mappings/sequences, quoted strings, comments, type coercion
- Not supported
- Anchors/aliases, multi-document files, block scalars (| and >)
- Verification method
- Cross-checked against js-yaml during development
- Output quoting
- Automatic re-quoting of ambiguous strings on JSON → YAML
- Indentation
- 2-space block style on output
- Processing location
- 100% local, in your browser
Privacy & security
Config files often encode real infrastructure details — service names, environment variables, internal hostnames — so conversion shouldn't require sending them to a server.
Every conversion runs locally in your browser using a self-contained YAML parser — nothing is ever uploaded.
No account, no email, no login — just data in, converted data out.
Nothing is retained after you close the tab; there's no copy waiting on a remote server.
Equally private whether you're converting a public example or a real production config.
Frequently asked questions
Is my config file uploaded anywhere?
No. Every conversion happens entirely in your browser — nothing is ever uploaded.
How was the YAML parser verified to be correct?
Its output was cross-checked against js-yaml, a mature and widely-used YAML library, across a range of representative documents during development — not trusted on faith.
Does this support YAML anchors and aliases?
No — that's an explicit scope limitation. Anchors/aliases and multi-document files aren't supported.
Will converting JSON to YAML and back give me the exact same data?
Yes, for the supported subset — this was specifically verified with round-trip tests (JSON → YAML → JSON) to confirm values come back unchanged.
Can this handle deeply nested config files like Kubernetes manifests?
Yes — nested mappings and sequences of any depth are supported.
Troubleshooting
I get a parse error on my YAML
Check indentation first — YAML uses indentation to represent nesting, and mixing tabs and spaces or using inconsistent indent widths is the most common cause of parse failures.
A string like "true" or "42" came back as a boolean or number
In standard YAML, unquoted true/false and numeric-looking values are interpreted as their respective types — if you need them as literal strings, quote them in the source YAML.
My YAML uses anchors (&ref) and aliases (*ref) and it failed
Anchors and aliases aren't supported by this converter — they're a less common YAML feature primarily used to avoid repetition in large config files.
Multi-document YAML (separated by ---) isn't converting as expected
This tool handles a single YAML document at a time — split multi-document files and convert each document separately.
Related searches
Landed here looking for something worded a little differently? YAML ⇄ JSON Converter covers all of these too:
Ready to use YAML ⇄ JSON Converter?
Free, private, and ready right now — no signup required.
Scroll to YAML ⇄ JSON Converter