true vs "true": Booleans and Strings in JSON

Quick answer: In JSON, true is a boolean and "true" is a string — different types entirely. The same goes for 5 (number) vs "5" (string). The quotes are not decoration; they change the type. Mixing them up causes silent bugs, because "false" is a non-empty string and therefore truthy. Confirm the actual types of a payload in the JSON Structure Analyzer.

JSON has exactly six data types. Two of them look confusingly similar in text:

{ "active": true, "label": "true" }

active is the boolean true; label is the four-character string "true". Likewise:

{ "count": 5, "code": "5" }

count is the number 5; code is the string "5". A validator or a strongly-typed consumer treats these very differently.

The nastiest case is a boolean accidentally serialized as a string:

const flag = JSON.parse('{"enabled": "false"}').enabled;
if (flag) {
  // THIS RUNS — "false" is a non-empty string, which is truthy!
}

Boolean("false") is true, because any non-empty string is truthy in JavaScript. So a feature you meant to disable stays on. The same trap hits "0" (truthy string vs falsy number) and "null" (a string, not null).

These usually come from:

• Form data and query strings, where everything arrives as text (?enabled=false).
• Environment variables, which are always strings.
• Spreadsheets / CSV imports, where types are lost.
• Over-eager quoting when hand-writing JSON.

• Keep the real type in JSON. Emit true/false and numbers without quotes. Generating JSON with JSON.stringify() from real booleans and numbers does this automatically — see Parse and Stringify.
• Convert at the boundary when input is unavoidably stringy:

const enabled = String(raw).toLowerCase() === "true";   // explicit, safe
const count = Number(rawCount);                          // not "5" forever

• Validate types with a schema. {"type": "boolean"} rejects "true"; {"type": "integer"} rejects "5". See JSON Schema Basics and the JSON Best Practices Checker.

Never test a stringified boolean with a bare truthiness check — compare explicitly.

Is true the same as "true" in JSON? No. true is a boolean value; "true" is a string of four characters. They are different types and behave differently in validation and code.

Why does "false" evaluate as true in my code? Because "false" is a non-empty string, and non-empty strings are truthy in JavaScript. You're testing the string's truthiness, not its content. Compare explicitly: value === "true".

Is 5 the same as "5" in JSON? No. 5 is a number and "5" is a string. Arithmetic, sorting, and schema validation all treat them differently, so keep numbers unquoted unless they're genuinely identifiers.

How do I safely convert a string boolean? Compare it explicitly, e.g. String(value).toLowerCase() === "true", rather than relying on truthiness. For numbers, use Number(value) and check for NaN.