YAML is friendly to write and easy to read, but APIs, browsers and many tools only accept JSON — and hand-converting a nested file is exactly where a stray indent turns into a silent bug. This free YAML to JSON converter turns pasted YAML or a dropped .yaml or .yml file into valid JSON instantly. Choose pretty-printed output with 2-space indent for reading, or minified JSON for sending, then copy it or download it as a .json file. The conversion happens locally in your browser, nothing is uploaded, so private configs stay on your machine.
How the YAML to JSON converter works
The converter parses your text with the js-yaml library, and then writes the resulting value out as JSON. Mappings become JSON objects, sequences become arrays, and plain scalars are typed the way YAML intends: an unquoted 42 becomes the number 42, true becomes a boolean, and a quoted “123” stays a string. If the YAML cannot be parsed, the tool stops and shows the parser’s message with the line and column where the problem was found.
How to use it
Paste your YAML into the top box, or drag a .yaml or .yml file onto the drop area and let the file fill the box for you. Choose Pretty print (2 spaces) when you want to read, review or diff the result, or Minified when you want the smallest possible payload for an API call or a config value. Press Convert to JSON and read the result below. Copy JSON puts it on your clipboard, and Download .json saves it as a file named converted.json.
Why convert YAML to JSON at all?
Because the two formats live on opposite sides of most projects. People write YAML: deployment manifests, CI pipelines, translation files and application settings are all easier to maintain with indentation and comments. Machines exchange JSON: a REST API expects it, a browser parses it natively, and most languages ship a strict JSON parser built in. Converting is the bridge between the file a person maintains and the payload a system consumes, and a real parser keeps nested lists and quoted strings intact.
Pretty print or minified: which should you pick?
Pretty-printed JSON spreads every object and array across indented lines. It is larger, but right for anything a person will read again: code reviews, saved fixtures and files in a repository where a clean diff matters. Minified JSON removes every unnecessary space and newline, producing one long line that is smaller to send and store. Pick minified for inline values, environment variables, one-off API tests and anywhere size counts more than readability. The data itself is identical either way; only the whitespace changes.
How YAML types become JSON types
Most values translate directly: strings stay strings, integers and decimals stay numbers, booleans stay booleans, and an empty value or null becomes JSON null. Lists and nested mappings keep their shape and order. Two cases deserve care. A date written plainly in YAML can be read as a date value and will appear in JSON as an ISO-style string, because JSON has no date type. YAML-only extras such as anchors and custom tags have no JSON equivalent: anchors are resolved to their values, and custom tags may need simplifying first.
Limitations worth knowing
Only single-document YAML is supported: if a file contains several documents separated by lines of three dashes, the converter reads the first document and ignores the rest, so split multi-document files before converting them. Comments cannot survive, because JSON has no comment syntax. Duplicate keys in one mapping follow the parser’s normal rule and the later value wins. Finally, the privacy point bears repeating: the conversion happens locally in your browser, nothing is uploaded to a server.
YAML to JSON Converter – frequently asked questions
Is the YAML to JSON converter free?
Yes. It is completely free, needs no sign-up, and you can convert as many files as you like.
Is my YAML uploaded anywhere?
No. The conversion happens locally in your browser, nothing is uploaded, and closing the page leaves nothing behind.
What if my YAML has an error?
You get a friendly message that includes the line and column from the parser when they are available, which usually points to the bad indent or stray tab. YAML forbids tabs, so check for them first.
Does it support YAML with multiple documents?
Only partly. Files with several documents separated by ——— are read as a single-document conversion: the first document is converted and the rest are ignored. Split the file and convert each document on its own for a complete result.
Related tools
Versión en español: Convertir YAML a JSON gratis – Obtén JSON válido al instante. You may also like: JSON to YAML Converter – Clean YAML for Config Files · JSON to CSV Converter – Export JSON Data to a CSV File Free.
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