JSON Validator

JSON Explained

What does this validator check?

The validator parses your text with a strict parser that implements RFC 8259 and ECMA-404. Every character is examined: when the document is not valid the exact line and column of the first problem is reported together with an excerpt of the source.

The JSON rules

• A document contains exactly one value: an object, an array, a string, a number, true, false or null.
• Objects are written { "name": value, ... }. Names must be strings in double quotes.
• Arrays are written [ value, value, ... ].
• Values are separated by commas. A trailing comma is not allowed.
• Strings use double quotes only. Characters ", \ and control characters must be escaped.
• Numbers: optional minus sign, integer part without leading zeroes, optional fraction and exponent.
• The literals are lower-case: true, false, null.
• Whitespace is allowed between tokens. Comments are not part of JSON.

Strict versus lenient

By default the validator is strict. Tick the options to accept common extensions: non-quoted names, single-quotes, NaN/Infinity, leading zeroes, comments, trailing commas.