uint256 converter
Convert between hex, decimal, utf-8 text, uint256 and bytes32. Everything is computed in your browser — no input ever leaves this page.
- hex minimal, byte-aligned
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- decimal the uint256 value
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- utf-8 text, trailing 0x00 padding ignored
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- uint256 32 bytes, left-padded — how a number is ABI-encoded
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- bytes32 32 bytes, right-padded — how a short string is ABI-encoded
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- ether value ÷ 10¹⁸
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- gwei value ÷ 10⁹
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What is uint256?
uint256 is the workhorse number type of the Ethereum Virtual Machine: an
unsigned integer that is 256 bits (32 bytes)
wide. Unsigned means it has no sign bit, so it holds whole numbers from
0 up to 2²⁵⁶ − 1. 256 bits is also the EVM's native word size, which is
why balances, token IDs, timestamps and hashes are all shaped like this.
Read the full uint256 reference →
Why the two padded rows differ
A 32-byte value can be padded from either side, and picking the wrong one silently changes the
value. Numbers are left-padded (uint256), short strings are
right-padded (bytes32), so the converter always shows both:
| Input | uint256 (left-padded) | bytes32 (right-padded) |
|---|---|---|
123 |
0x00…007b |
0x7b00…00 |
hello |
0x00…68656c6c6f |
0x68656c6c6f…00 |
Common uses
- Reading raw
uint256values from a block explorer or aneth_callresult. - Encoding a short string as
bytes32for a contract argument. - Converting wei amounts to ether while minting or transferring.
- Checking whether a value still fits into 256 bits.