JSON ⇄ YAML Converter — Free & Private API

Free, no signup, runs entirely in your browser — your data never leaves your device.

Usage

JSON → YAML (GET):

curl "https://json-yaml-formatho.filesformatho.workers.dev/api?json=%7B%22name%22%3A%22formatho%22%2C%22private%22%3Atrue%7D"

YAML → JSON (GET):

curl "https://json-yaml-formatho.filesformatho.workers.dev/api?yaml=name%3A%20formatho%0Aprivate%3A%20true"

Or POST the raw content to https://json-yaml-formatho.filesformatho.workers.dev/api — JSON and YAML are auto-detected. POST ?format=json or ?format=yaml to force the input type.

Supports the common YAML subset: block maps & sequences, flow [..]/{..}, quoted strings, comments, block scalars (|, >), null/bool/int/float typing. Anchors, aliases, tags and multi-document YAML return clean 400 errors.

Full parameter reference: /api endpoint.

Full browser tool

Convert JSON ⇄ YAML entirely client-side: JSON ⇄ YAML Converter on formatho.com.

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