BRev JSON ⇄ YAML ⇄ TOML converter
Paste or drop JSON, JSON5, YAML or TOML and convert any-to-any — with an honest, itemized report of everything the target format cannot carry: comments, anchors, TOML date types, nulls, oversized integers and YAML 1.1/1.2 ambiguities like the Norway problem. Everything runs on your device.
The Norway problem: in YAML 1.1 the bare word no is the boolean false — so a list of country codes quietly turns Norway into false. YAML 1.2 reads no, yes, on and off as plain strings, but plenty of parsers still speak 1.1, which is why this tool checks every plain scalar against both readings and shows you the difference before it bites.
Why comments can't survive JSON: converters exchange data, and JSON's data model has no comment syntax at all — a comment in YAML or TOML simply has nowhere to go. Instead of dropping them silently, this tool counts every dropped comment and reports it, along with expanded YAML anchors, TOML dates turned into strings, null values TOML can't hold, and integers too big for JavaScript.