web3-utils

What is web3-utils?

The web3-utils package provides utility functions for Ethereum dapps and other web3.js applications. It includes methods for unit conversion, address formatting, and encoding/decoding of data among other utilities.

What are web3-utils's main functionalities?

Unit Conversion

Converts Wei to other units of Ether such as 'ether', 'gwei', etc.

const Web3Utils = require('web3-utils');
let etherValue = Web3Utils.fromWei('21000000000000', 'ether');

Address Formatting

Converts an Ethereum address to a checksum address to prevent case-sensitivity errors.

const Web3Utils = require('web3-utils');
let checksumAddress = Web3Utils.toChecksumAddress('0xfb6916095ca1df60bb79ce92ce3ea74c37c5d359');

Data Encoding and Decoding

Encodes data using SHA3 or other encoding methods.

const Web3Utils = require('web3-utils');
let encodedData = Web3Utils.sha3('Some data to be hashed');

Random Hex Strings

Generates a random hex string of a given size.

const Web3Utils = require('web3-utils');
let randomHex = Web3Utils.randomHex(32);

BN (BigNumber)

Creates a BigNumber instance which can handle large integers safely.

const Web3Utils = require('web3-utils');
let bigNumber = Web3Utils.toBN('123456');

Other packages similar to web3-utils

ethers

Ethers is a complete Ethereum library and wallet implementation. It provides a similar set of utilities for unit conversion, address handling, and encoding/decoding data. It is often considered a lighter and more modular alternative to web3.js.

ethereumjs-util

Ethereumjs-util is a collection of utility functions for Ethereum, such as account creation and conversion, transaction signing, and data encoding. It is a part of the ethereumjs suite of packages and is more focused on lower-level operations compared to web3-utils.

bignumber.js

While not Ethereum-specific, bignumber.js is a general-purpose library for arbitrary-precision decimal and non-decimal arithmetic. It can be used in place of the BN (BigNumber) functionality provided by web3-utils.

README

web3-utils

This is a sub package of web3.js

This contains useful utility functions for Dapp developers.
Please read the documentation for more.

Installation

Node.js

npm install web3-utils

In the Browser

Build running the following in the web3.js repository:

npm run-script build-all

Then include dist/web3-utils.js in your html file. This will expose the Web3Utils object on the window object.

Usage

// in node.js
var Web3Utils = require('web3-utils');
console.log(Web3Utils);
{
    sha3: function(){},
    soliditySha3: function(){},
    isAddress: function(){},
    ...
}

Types

All the typescript typings are placed in the types folder.

Changelog

[1.2.5]

Added

• eth_requestAccounts as requestAccounts added to web3-eth package (#3219)
• sha3Raw and soliditySha3Raw added to web3-utils package (#3226)
• eth_getProof as getProof added to web3-eth package (#3220)
• BN and BigNumber objects are now supported by the abi.encodeParameter(s) method (#3238)
• getPendingTransactions added to web3-eth package (#3239)
• Revert instruction handling added which can get activated with the handleRevert module property (#3248)
• The receipt does now exist as property on the error object for transaction related errors (#3259)
• internalType added to AbiInput TS interface in web3-utils (#3279)
• Agent option added to the HttpProvider options (#2980)

Changed

• eth-lib dependency updated (0.2.7 => ^0.2.8) (#3242)

Fixed

• Fix crash when decoding events with identical signatures, differently indexed args (#3272)
• Fix user supplied callback not fired in eth.accounts.signTransaction (#3283)
• Fix minified bundle (#3256)
• defaultBlock property handling fixed (#3247)
• clearSubscriptions does no longer throw an error if no running subscriptions do exist (#3246)
• callback type definition for Accounts.signTransaction fixed (#3280)
• fix: export bloom functions on the index.js
• Prefer receipt status to code availability on contract deployment (#3298)