BigInt

Added in ves2020 · Updated March 13, 2026 · Built-in Objects

javascript bigint es2020

BigInt is a built-in object that represents arbitrary-precision integers. It allows you to work with integers larger than the safe integer limit (Number.MAX_SAFE_INTEGER, which is 2^53 - 1).

Creating BigInt Values

Create a BigInt by appending n to an integer literal, or by calling the BigInt() function:

const bigNumber = 9007199254740993n;
// 9007199254740993n

const fromString = BigInt("9007199254740993");
// 9007199254740993n

const fromNumber = BigInt(9007199254740993);
// 9007199254740993n

Arithmetic Operations

BigInt supports the standard arithmetic operators:

const a = 10n;
const b = 5n;

a + b    // 15n
a - b    // 5n
a * b    // 50n
a / b    // 2n
a % b    // 0n
a ** b   // 100000n (exponentiation)

The unary minus operator works with BigInt:

-5n      // -5n

Comparison Operations

BigInt values can be compared with other BigInt or Number values:

5n > 3        // true
5n === 5      // false (strict equality: different type)
5n == 5       // true (loose equality)
0n === 0n     // true

Use BigInt.asUintN() and BigInt.asIntN() to clamp values to a specific bit width:

BigInt.asUintN(8, 300n)   // 44n (300 mod 256)
BigInt.asIntN(8, 300n)    // 44n
BigInt.asIntN(8, 130n)    // -126n (130 - 256)

Type Checking

Check if a value is a BigInt using typeof:

typeof 10n   // "bigint"

Limitations

Cannot mix BigInt with Number in arithmetic operations
Cannot use Math functions with BigInt values
BigInt() without arguments returns 0n

Practical Examples

Working with Large Numbers

// Calculate factorial of 50
function factorial(n) {
  if (n <= 1n) return 1n;
  return n * factorial(n - 1n);
}

const result = factorial(50n);
// 30414093201713378043612608166064768844377641568960512000000000000n

Bitwise Operations

const value = 15n;

value >> 2n   // 3n
value << 2n   // 60n
(value | 1n)  // 15n (already odd)