JSON ↔ YAML ↔ TOML Roundtrip Converter

Three formats, one editor. Edit JSON on the left and YAML / TOML update on the right (and vice versa). Useful when migrating configs between formats — your Hugo TOML site to Jekyll YAML, your Kubernetes YAML to a JSON ConfigMap, etc.

How to use the JSON ↔ YAML ↔ TOML Roundtrip Converter

Edit any pane; the other two update automatically. TOML has limitations (no nulls, top-level must be a table); the tool flags conversions that lose information.

Converting between JSON, YAML, and TOML

Config formats rarely sit still: a Hugo site uses TOML, Jekyll wants YAML, a Kubernetes ConfigMap takes JSON, and sooner or later you need to move settings from one to another. Converting through a single pair at a time is slow, and TOML in particular has limits — no nulls, and the top level must be a table — that quietly lose data if you are not watching.

This shows all three formats side by side in a three-pane editor: edit any pane and the other two update live, so you can paste JSON and read off the YAML and TOML, or vice versa. It flags conversions where TOML cannot represent the data faithfully. For a single one-way conversion the YAML to JSON and TOML converter tools are more direct.

Common use cases

  • Migrate config — move a site or app config between TOML, YAML, and JSON.
  • Compare formats — see the same data in all three at once.
  • Spot lossy TOML — get warned when a value will not survive the TOML conversion.
  • Edit live — change any pane and watch the others update.
  • Learn the syntax — see how a structure looks across the three formats.

Frequently asked questions

How does the three-pane editor work?

Edit any one pane and the other two regenerate automatically, so all three stay in sync.

Why are some conversions flagged?

TOML cannot represent everything — it has no null and requires a table at the top level — so the tool warns when a conversion would lose information.

When should I use a one-way converter instead?

For a single conversion the YAML to JSON and TOML converter tools are more direct.

Does it run in the browser?

Yes — all conversion happens locally in your browser; nothing is uploaded.
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