JSON ↓ YAML ↓ TOML Converter

JSON ↔ YAML ↔ TOML Converter — Instant Format Conversion for Developers

Modern software development touches all three of these data formats regularly. APIs speak JSON (RFC 8259). Infrastructure-as-code, Kubernetes manifests, GitHub Actions workflows, and Docker Compose files use YAML. Rust projects use Cargo.toml, Python packaging uses pyproject.toml, and Hugo static sites use config.toml. When you need to convert between these formats — to adapt a config for a new tool, migrate a pipeline file, or verify round-trip equivalence — this converter handles all six conversion directions instantly in your browser.

How to convert between formats

Select your input format on the left (JSON, YAML, or TOML), then select your desired output format on the right. Paste your data into the input panel and the converted output updates live in the right panel as you type, properly formatted for the target format. Very large inputs (over 500 KB) convert on demand with a Convert now button so typing stays smooth. Use the ⇄ Swap button to quickly reverse direction — useful for round-trip testing where you convert from JSON to YAML and then back to verify nothing was lost or mutated in translation. Click Copy to grab the converted output for immediate use in your project.

Format differences that matter in practice

JSON is strict: all strings must be double-quoted, no trailing commas, no comments allowed. YAML is human-friendly but whitespace-sensitive — indentation defines structure, which makes it easy to introduce bugs by inconsistent spacing. TOML is designed for configuration files specifically: it uses INI-style sections, supports comments natively, and has cleaner syntax for arrays of tables than YAML. When converting, be aware that YAML comments are lost on any round-trip (JSON and TOML both lack comment support), and TOML datetime types have no JSON equivalent.

Who uses this tool

DevOps engineers use it to convert between Kubernetes YAML manifests and JSON format when debugging API responses or writing Helm chart values. Rust developers use it to convert JSON API responses into TOML format when building configuration files. Backend developers use it to quickly validate that a YAML config they wrote is syntactically valid by converting it to JSON and checking the output structure. Python developers use it when migrating from setup.cfg to pyproject.toml format.

Privacy and data handling

All conversion runs 100% in your browser using JavaScript — your configuration data, API keys, secrets, and infrastructure definitions never leave your device and are never sent to any server.