JSON / YAML / TOML Converter
Convert between JSON, YAML, and TOML instantly. Everything runs in your browser.
How to use this tool
- Paste your JSON, YAML, or TOML into the input area
- The format is auto-detected, or you can select it manually
- Choose your target format from the output dropdown
- The conversion happens instantly — copy the result with one click
Everything runs in your browser. Your configuration data is never sent to any server.
When to use each format
JSON (JavaScript Object Notation)
The most widely used data interchange format for APIs and web applications. Strict syntax, well-supported by every language, but does not allow comments. Used in: package.json, tsconfig.json, API responses, REST/GraphQL payloads.
YAML (YAML Ain't Markup Language)
Popular for configuration files thanks to its human-readable syntax. Supports comments, anchors, and multi-line strings. Sensitive to indentation — a common source of errors. Used in: docker-compose.yml, GitHub Actions, Kubernetes manifests, Ansible playbooks.
TOML (Tom's Obvious, Minimal Language)
Designed to be a minimal, unambiguous configuration format. Supports comments, date/time types, and avoids indentation issues. Gaining popularity in modern toolchains. Used in: Cargo.toml (Rust), pyproject.toml (Python), Hugo, Deno.
Format comparison
| Feature | JSON | YAML | TOML |
|---|---|---|---|
| Comments | No | Yes | Yes |
| Indentation-sensitive | No | Yes | No |
| Date/time types | No | Partial | Yes |
| Multi-line strings | No | Yes | Yes |
| Nesting depth | Unlimited | Unlimited | Limited |
Common use cases
- Converting Kubernetes YAML to JSON for API calls
- Migrating config files between formats (e.g. JSON to TOML for a Rust project)
- Debugging malformed YAML by converting to JSON for validation
- Generating YAML from JSON API responses for documentation
FAQ
Is my data sent to a server?
No. All conversions happen locally in your browser using JavaScript. No data leaves your device.
Are comments preserved during conversion?
Comments are lost when converting from YAML/TOML to JSON, since JSON does not support comments. Converting between YAML and TOML may also lose comments depending on the parser.
What happens with invalid input?
The tool will show a parse error with details about where the syntax issue is. Fix the input and the conversion updates automatically.