JavaScript BigInt
JavaScript BigInt variables are used to store big integer values
that are too big to be represented by a normal JavaScript Number.
JavaScript Integer Accuracy
JavaScript integers are only accurate up to 15 digits:
In JavaScript, all numbers are stored in a 64-bit floating-point format (IEEE 754 standard).
With this standard, large integer cannot be exactly represented and will be rounded.
Because of this, JavaScript can only safely represent integers:
Up to 9007199254740991 +(253-1)
and
Down to -9007199254740991 -(253-1).
Integer values outside this range lose precision.
How to Create a BigInt
To create a BigInt, append n to the end of an integer or call
BigInt():
Examples
let x = 9999999999999999;
let y = 9999999999999999n;
Try it Yourself »
let x = 1234567890123456789012345n;
let y = BigInt(1234567890123456789012345)
Try it Yourself »
BigInt: A new JavaScript Datatype
The JavaScript typeof a BigInt is "bigint":
BigInt is the second numeric data type in JavaScript
(after Number).
With BigInt the total number of supported data types in JavaScript is 8:
1. String
2. Number
3. Bigint
4. Boolean
5. Undefined
6. Null
7. Symbol
8. Object
BigInt Operators
Operators that can be used on a JavaScript Number
can also be used on a BigInt.
BigInt Multiplication Example
let x = 9007199254740995n;
let y = 9007199254740995n;
let z = x * y;
Try it Yourself »
Notes
Arithmetic between a BigInt
and a Number is not allowed (type conversion lose information).
Unsigned right shift (>>>) can not be done on a BigInt
(it does not have a fixed width).
BigInt Decimals
A BigInt can not have decimals.
BigInt Division Example
let x = 5n;
let y = x / 2;
// Error: Cannot mix BigInt and other types, use explicit conversion.
let x = 5n;
let y = Number(x) / 2;
Try it Yourself »
BigInt Hex, Octal and Binary
BigInt can also be written in hexadecimal, octal, or binary notation:
BigInt Hex Example
let hex = 0x20000000000003n;
let oct = 0o400000000000000003n;
let bin = 0b100000000000000000000000000000000000000000000000000011n;
Try it Yourself »
Precision Curiosity
Rounding can compromise program security:
Browser Support
BigInt is supported in all browsers since September 2020:
| Chrome 67 | Edge 79 | Firefox 68 | Safari 14 | Opera 54 |
| May 2018 | Jan 2020 | Jul 2019 | Sep 2020 | Jun 2018 |
Minimum and Maximum Safe Integers
ES6 added max and min properties to the Number object:
MAX_SAFE_INTEGERMIN_SAFE_INTEGER
New Number Methods
ES6 also added 2 new methods to the Number object:
Number.isInteger()Number.isSafeInteger()
The Number.isInteger() Method
The Number.isInteger() method returns true if the argument is an integer.
The Number.isSafeInteger() Method
A safe integer is an integer that can be exactly represented as a double precision number.
The Number.isSafeInteger() method returns true if the argument is a safe integer.
Example isSafeInteger()
Number.isSafeInteger(10);
Number.isSafeInteger(12345678901234567890);
Try it Yourself »
Safe integers are all integers from -(253 - 1) to +(253 - 1).
This is safe: 9007199254740991. This is not safe: 9007199254740992.
