# Uint256 max value

The maximum value of uint256 can be obtained with

```javascript
type(uint256).max;
```

Which is equal to 115792089237316195423570985008687907853269984665640564039457584007913129639935 (2²⁵⁶ — 1). But it’s cleaner and safer to use type(uint256).max.

The same can be used for signed integer types

```javascript
//57896044618658097711785492504343953926634992332820282019728792003956564819967
type(int256).max;

//-57896044618658097711785492504343953926634992332820282019728792003956564819968
type(int256).min;
```

### Hacky ways to get the uint256 maximum value

You could also specify it with hexadecimal, which would be a little cleaner than using the decimal representation, but still space consuming and error prone.

```javascript
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
```

That’s exactly 64 ‘f’s, don’t get it wrong! The 64 is derived from 256 bits divided by 8 to get the number of bytes (32), and each maximum byte is represented in hex by 0xff.

Another ugly solution is to underflow the integer

```javascript
function maximum() public pure returns(uint256) {
   unchecked { return uint256(0) - uint256(1); }
}
```

The following code works properly, but it is deceptive and not recommended for use

```javascript
function maxUint() public pure returns (uint256) {
    return 2**256 - 1;
}
```

It returns the correct value, which you can verify with

```javascript
assert(2**256 - 1 == type(uint256).max);
```

If you write 2\*\*256 as a constant in solidity, the code won’t compile because the compiler recognized 2\*\*256 is too large to fit in uint256. But if it is immediately followed by a “- 1”, then the compiler recognized the result of the arithmetic is valid with the type.

It’s better to just avoid all these gymnastics and just do type(uint256).max;

### Learn more

If you are new to Solidity, see our [learn solidity free for beginners course](https://rareskills.io/learn-solidity).

For intermediate and advanced developers, please see our expert [solidity bootcamp](https://www.rareskills.io/solidity-bootcamp).