YAML ↔ JSON ↔ TOML

YAML is a human-friendly superset of JSON with support for comments, anchors, aliases, and multi-line strings. JSON is a strict data format optimized for machine interchange. YAML is easier to write by hand; JSON is easier to parse in code and is universally supported by every language and framework without extra libraries.

Paste your YAML into the left panel. The JSON output appears instantly in the right panel. Use the Copy button to copy the result to your clipboard, or click Download to save it as a .json file. No account required, no data sent to a server.

Anchors (&name) define a reusable value, and aliases (*name) reference it. For example, &defaults defines a base config object, and <<: *defaults merges it into other objects. This avoids duplicating configuration. This tool fully resolves anchors and aliases during conversion using the js-yaml library.

TOML (Tom's Obvious Minimal Language) is a config file format focused on being easy to parse. It uses [sections] and key = value syntax, and has explicit types for dates, booleans, and arrays. YAML is more expressive but significantly more complex to parse correctly. TOML is simpler but less flexible for deeply nested or dynamic data structures. Use TOML for application configuration; YAML for data serialization and CI/CD pipelines.

No. All conversion happens entirely in your browser using the open-source js-yaml and @iarna/toml libraries. Your data never leaves your device and is not stored anywhere. You can verify this in your browser's network inspector — no requests are made when you type or paste content.