Cómo usar: JSON Validator
- Paste your JSON — it is validated as you type.
- If there is an error, jump to the reported line and column and read the explanation.
- Valid JSON is formatted; switch to Minify or sort keys if you need to.
The most common JSON errors
- Trailing comma —
{"a": 1,}is valid JavaScript but not JSON. - Single quotes — JSON strings and keys need double quotes:
"name", not'name'. - Unquoted keys —
{name: "x"}must be{"name": "x"}. - Missing comma between two values or properties.
- Comments —
// …and/* … */are not allowed in JSON. - Special values —
NaN,Infinityandundefineddon’t exist in JSON.
Strict validation
The validator follows RFC 8259, the same rules as JSON.parse() in browsers and every standard JSON library. If it validates here, it will parse in JavaScript, Python, Java, Go and PHP.
Validating against a schema
Syntax validation checks that the text is JSON. To check that it has the right structure — required fields, types, allowed values — use the JSON Schema Validator.
También se busca como: validate json, json checker, json lint, json syntax checker, check json online, jsonlint, json error finder.
Herramientas que combinan con: JSON Validator
- Formateador JSON — Pega el código JSON para formatearlo, minimizarlo o validarlo.
- JSON Schema Validator — Paste a schema and some JSON to see exactly which values break which rule — or generate a starting schema from example data.
- JSON Viewer — Explore big or deeply nested JSON comfortably: fold and unfold objects, search for keys or values and click any node to get its JSONPath.
- JSON Diff — Find exactly what changed between two JSON documents — API responses, config versions, fixtures or exports — as a list of paths with old and new values.
Preguntas frecuentes
Why is my JSON invalid?
Most often because of a trailing comma, single quotes, an unquoted key or a missing comma. The error message points to the line and column where parsing failed.
Does JSON allow comments?
No. Standard JSON has no comments. Some tools accept JSONC or JSON5, but APIs and JSON.parse() do not.
What is the difference between a JSON validator and JSON Schema validation?
A validator checks syntax. JSON Schema validation checks that valid JSON also has the expected structure and types.
¿Puedo instalar JSON Validator como aplicación web y utilizarla sin conexión?
Sí. JSON Validator es una aplicación web instalable (PWA): se instala desde el navegador, no se descarga desde una tienda de aplicaciones. Haz clic en «Instalar aplicación» en la parte superior de esta página en Chrome o Edge (Windows, macOS, Linux, ChromeOS) o, en Android, utiliza «Compartir» → «Añadir a la pantalla de inicio» en iPhone y iPad, o «Archivo» → «Añadir al Dock» en Safari 17+ en un Mac. A continuación, se abrirá en su propia ventana con su propio icono y, como se ejecuta íntegramente en tu navegador, seguirá funcionando sin conexión. Firefox en el ordenador de sobremesa no permite instalar aplicaciones web. Cómo funciona la instalación.