JavaScript libraries for blockchain development

Anton Ioffe - October 3rd 2023 - 19 minutes read

As the world of technology continues to evolve and disrupt traditional systems, the role of blockchain in transforming various sectors has become undeniably significant. Many developers are now keen on mastering this robust technology. Inline with this trend, an understanding of JavaScript libraries designed for blockchain development has become a pressing necessity for modern web developers who are looking to remain at the forefront of technological innovation.

This article embarks on an explorative endeavor of JavaScript libraries that serve as powerful allies for blockchain development. Going beyond a simple list of libraries, it sheds light on the core characteristics, performance metrics, constraints, and workarounds for each library, all matched with concrete examples and demonstrated through real-world code.

From analyzing the dominance of Web3.js in Ethereum Development to casting the limelight on Polkadot's JavaScript library for interoperability, the article encompasses a comprehensive review of useful libraries. Whether you're keen on enhancing your Ethereum project with Web3.js or Ethers.js, stepping into decentralized applications with Truffle Suite, or eager to unravel the potentials of @binance-chain/javascript-sdk, this article avails you the critical insights and deep dives to guide your JavaScript blockchain journey.

Making Sense of JavaScript's Alliance with Blockchain

JavaScript has emerged as a prevalent force in the development landscape, notably extending its influence to the burgeoning field of blockchain technology. The alliance between these two technological realms is intriguing to unpack, given their distinctive benefits that synergistically expand programming feasibility and effectiveness.

Why JavaScript for Blockchain?

Choosing the right language for coding blockchain applications is a paramount decision. In many cases, JavaScript shines as a stellar option due to its benefits in terms of performance, readability, and reusability.

JavaScript's event-driven paradigm is highly suited for blockchain development. Blockchain transactions inherently involve waiting times, which can block application flows. JavaScript copes deftly with such cases, ensuring smooth, uninterrupted operations.

eventEmitter.on('transactionConfirmed', () => {
    // Once the transaction is confirmed, the rest of the code can proceed.

Its asynchronous behavior, geared towards handling I/O-bound tasks efficiently, also complements blockchain, where network latency and transaction processing are major factors.

Moreover, JavaScript is cross-platform, which means the same code can run on a variety of devices, broadening the blockchain application's reach.

(js code block example)

// JS code is platform independent.
let platform = process.platform;
console.log(`Running on ${platform}`);

JavaScript's Pitfalls in Blockchain

While JavaScript is powerful, there are specific potential pitfalls to avoid when using this language for blockchain development.

Floating Point Precision

JavaScript represents all numbers using IEEE-754 double-precision floating point, which can lead to unexpected results when performing arithmetic operations involving decimals.

let amount = 0.1 + 0.2;  // Outputs 0.30000000000000004 instead of 0.3

In a blockchain environment, transactions involving such arithmetic operations may lead to incorrect record keeping and consequently, loss of financial data.

The Remedy: Always use libraries like 'decimal.js' or 'bignumber.js' that provide precise arithmetic operations.

const Decimal = require('decimal.js');
let amount = new Decimal(0.1).plus(new Decimal(0.2));
console.log(amount.toString());  // Now it correctly outputs 0.3

Mutability of Arrays and Objects

In JavaScript, arrays and objects are mutable. This can cause problems in blockchain where data integrity is crucial.

let transaction = {amount: 100};
let anotherTransaction = transaction;
anotherTransaction.amount = 200;  // Modifies the original transaction

The Remedy: To preserve immutability, we can use 'Object.freeze()' method or third-party libraries such as 'immutable.js' that provide immutable data structures.

let transaction = Object.freeze({amount: 100});
let anotherTransaction = transaction;
anotherTransaction.amount = 200;  // Now it correctly raises an error against modification

Thought-Provoking Questions

  1. How does JavaScript's single-threaded nature influence its suitability for blockchain development?
  2. Could JavaScript's dynamic typing become a liability in creating secure blockchain applications?
  3. What steps can be taken to handle JavaScript's limitations regarding large number computations particularly in the context of blockchain?

In conclusion, JavaScript, despite its limitations, is a potent ally for blockchain development, primarily due to its asynchronous behavior, versatility across platforms, and sophisticated community support. The key is to be mindful of its specific quirks and pitfalls, as well as their remedies, to effectively leverage this language in the blockchain environment for optimal results.

Profiling Web3.js in Ethereum Development

Web3.js has become a mainstay in developing Ethereum-based applications, through its provision of an extensive range of functionality. As a JavaScript library, it allows developers to communicate with local or remote Ethereum nodes using HTTP, IPC, or WebSocket.

Highlighting Web3.js Standout Features

At its core, Web3.js simplifies the process of creating, querying, and interacting with Ethereum's blockchain. In the scope of Ethereum development, it has a number of standout features that make it a versatile option:

  1. Smart Contract Interaction: Web3.js provides an API for developers to read and write data from Ethereum contracts. This normally cumbersome process is greatly simplified through the abstraction provided by the library.

  2. Transaction Signing: It offers a set of utilities for generating, signing and broadcasting Ethereum transactions.

  3. Real-Time Updates: Web3.js supports Ethereum's Pub/Sub API, allowing developers to receive real-time updates about new blocks, transactions and other events happening on the Ethereum blockchain.

  4. Big Number Manipulation: Given Ethereum's inherent use of large numbers for token values, gas prices, and similar parameters, Web3.js provides an interface for 'Big Number' objects, enabling accurate arithmetic operations over very large numbers.

Below is an example of using Web3.js to interact with an Ethereum contract:

const web3 = new Web3('http://localhost:8545'); //Instantiate with Ethereum node URL
const contract = new web3.eth.Contract(myAbi, contractAddress); //Instantiate with ABI & contract address

    .call((err, result) => {

And here's the usage for subscribing for new blocks:

const subscription = web3.eth.subscribe('newBlockHeaders', (error, result) => {
    if (!error) {
    } else {

Analyzing Web3.js Performance

The performance of a blockchain solution depends on numerous aspects, including network conditions, design of the solution and the selected protocol. Web3.js, while feature-rich, can at times be hampered by its architecture and design, causing heavy memory and network usage, especially when working with large data structures.

One common application scenario of Web3.js is polling the Ethereum network for block updates. Using the Pub/Sub API, developers can achieve real-time updates, but such operations generally require a dedicated and high-bandwidth network connection.

Detecting Pitfalls with Web3.js

Being cognizant of potential pitfalls can help developers avoid common issues while navigating Web3.js. A ubiquitous problem is the handling of asynchronous functions leading to the infamous 'callback hell'. This issue is resolved by leveraging ECMAScript 6 where asynchronous methods can be handled using modern JavaScript's Promises and the async/await syntax. Here's rewriting previous block subscription code with catch clause for error handling:

    .on('data', (blockHeader) => {
    .on('error', console.error);

The example above illustrates the subscription being handled without callbacks and uses the 'on' method to add event handlers.

Managing large numbers is another challenge that is commonly faced. As Ethereum inherently uses large numbers, JavaScript's normal number handling can produce inaccurate results leading to bugs and other issues. This is handled effectively by Web3.js's Big Number objects. Here's an example of performing safe arithmetic operations:

let etherValue = web3.utils.toWei('10', 'ether');
console.log(etherValue); // Outputs: 10000000000000000000

In this example, you can see that even very large numbers can be handled accurately, thus mitigating the risk of introducing calculation errors in your application.

While each developer might have a different approach to solving problems with Ethereum, Web3.js presents a comprehensive selection of tools and solutions that can meet a diverse range of project requirements. It provides a solid foundation for initiating, deploying and managing decentralized applications on Ethereum's network while maintaining a strong cap on the complexity and verbosity of direct interaction with Ethereum's underlying machinery. Nonetheless, every tool has its trade-offs and as seen with Web3.js, the developer needs to balance between the richness of features and potential performance overheads.

Spotlight on Ethers.js: A Lightweight Alternative for Ethereum

With blockchain development maturing and gaining wider acceptance, several JavaScript libraries have positioned themselves as indispensable tools in the arsenal of modern developers. One of these libraries is ethers.js, which has established itself as a sturdy, lightweight, and comparably superior option for developers working on Ethereum-based projects. This section delves into ethers.js, highlighting its distinctive selling points, facilitating an analysis of its memory management, readability, and code complexity with concrete code examples.

Understanding Ethers.js

At its core, ethers.js is a comprehensive Ethereum library designed to interact with the Ethereum Blockchain and its ecosystem. It strives to keep consistency and simplicity in its design, making its operations as intuitive as possible.

A significant advantage of ethers.js over Web3.js lies in its lightweight nature. Unlike Web3.js, which requires around 1MB of space, ethers.js demands only about 75KB. This makes ethers.js more memory-efficient, and as such, provides an increased performance for the application.

let ethers = require('ethers');

let wallet = ethers.Wallet.createRandom();
console.log('Address: ' + wallet.address);

This simple script demonstrates the directness of creating a new Ethereum wallet with ethers.js.

Code Complexity and Readability With Ethers.js and Web3.js

The reduction in code complexity in ethers.js sets it apart from other libraries, especially Web3.js. With its simple API and smaller size, ethers.js is easy to understand and maintain.

let provider = ethers.getDefaultProvider('ropsten');
let wallet = new ethers.Wallet(privateKey, provider);

let transaction = {
    to: "0x88a5C2d9919e46F883EB62F7b8Dd9d0CC45bc290",
    value: ethers.utils.parseEther("1.0")

let sendPromise = wallet.sendTransaction(transaction);

The script above sets up a default provider and processes a transaction with the designated recipient and allocated Ether amount. Whilst this process is performed in similar steps using Web3.js, ethers.js presents a more streamlined and readable approach to handle such transactions.

Ethers.js Memory management and comparison with Web3.js

ethers.js shines in the realm of memory management. With less space needed compared to other libraries such as Web3.js, ethers.js ascends in terms of memory efficiency and system performance optimization.

let EthereumNameService = require('@ethersproject/address').EthereumNameService;

let ens = new EthereumNameService();
console.log(`ENS Name: ${ens.resolveName}`);

The snippet above demonstrates that with ethers.js, you only import the utility part you need. This encapsulated design helps manage memory efficiently.

Best Practices for Ethers.js

Upon viewing the examples, it becomes clear that ethers.js embraces a modular approach. Exploit this by only importing the necessary ethers.js modules that your project requires.

Furthermore, ethers.js employs promises extensively for asynchronous processing. Harness these promises to properly structure your asynchronous code, facilitating the handling of any unexpected errors that may arise.

.then(function(tx) {
.catch(function(error) {

In the example above, we handle the send transaction promise using the .then() method to log the transaction and .catch() method to handle any potential error.

In Conclusion

Due to its lightweight nature, simplicity, and memory management strategy, ethers.js has emerged as one of the popular JavaScript libraries for blockchain development. Furthermore, it extends modern JavaScript features and intuitive operations, which make ethers.js a favorable choice for Ethereum-based projects.

Thought-provoking question: Consider your past blockchain projects developed with JavaScript. How can including ethers.js in your framework library improve the performance, readability, and maintainability of your codebase moving forward?

Navigating Decentralized Applications with Truffle Suite

The Truffle Suite has emerged as a popular and dependable set of tools in the world of JavaScript blockchain development. At its core, Truffle Suite is an ecosystem designed for the development, testing, and asset pipeline management of blockchain-based decentralized applications (DApps) primarily on Ethereum.

The Suite offers a trio of tools, including:

  • Truffle : This is the centerpiece of the Suite, an effective and comprehensive development environment, testing framework, and asset pipeline.
  • Ganache : A powerful tool providing a personal blockchain for testing and experimenting.
  • Drizzle : A collection of front-end libraries for creating sleek, reactive interfaces for DApps.

Each of these components brings a plethora of functionalities to the table, highlighting the Truffle Suite's commitment to modularity and reusability.

Feature Analysis of Truffle Suite

Truffle offers a compiler for Solidity, the primary programming language for Ethereum DApps, along with a robust testing environment. It allows developers to compile and deploy contracts, link libraries, and manage complex contract workflows. Its automated contract testing, written in JavaScript, ensures resilient development practices.

Ganache, on the other hand, makes it possible to bootstrap a personal Ethereum blockchain that you can use to run tests, execute commands, and examine state changes while controlling the operation of the chain's internals.

Drizzle, completing the trio, facilitates the creation of user interfaces. Its reactive nature ensures that your user interface will always be in sync with the back-end blockchain state.

Truffle Suite: Advantages and Best Practices

The modularity and reusability of Truffle Suite are among its key strengths. You can decide to use all the Truffle tools or just the ones you need. This means developers can choose the specific functionality they need, resulting in increased efficiency and improved memory management.

When it comes to best practices, it's recommended to start with test-driven development, utilizing Truffle's testing environment. During testing, Ganache can be employed to execute the contracts in an isolated environment away from the live blockchain, thereby ensuring the integrity of data in the production chain.

Another best practice entails the use of Drizzle for developing user interfaces. Drizzle’s components are built with a Reactive mindset, thereby allowing for seamless data updates between your interface and the underlying blockchain.

Potential Issues with Truffle Suite

While Truffle Suite is powerful, it's not without its potential issues. To start with, Truffle's test runner doesn't currently support ES6 syntax, which can be a limitation for developers used to this syntax. Additionally, Truffle tests are often slower than traditional unit tests because they interact with the Ethereum Virtual Machine (EVM).

An existing concern with Ganache is that it doesn't perfectly emulate the behavior of the EVM, which might lead to successful tests in Ganache but failures in a production environment.

Although a great tool, Drizzle is still in its infancy and might lack some functionalities needed by developers. Furthermore, its documentation is also minimal, which can be a hurdle.

Despite these concerns, Truffle Suite remains a powerful and practical choice for those diving into Ethereum DApp development. The advantages it offers, coupled with its modularity and reusability, makes it an invaluable toolkit in this realm. Understanding the potential issues and how to navigate around them will ensure you get the most out of it.

The Impact of Node.js in Crafting Decentralized Solutions

Node.js has been instrumental in crafting decentralized solutions, thanks to its asynchronous architecture and high-performing, non-blocking I/O operations. Developers often use Node.js to build outperforming back-end servers for their Decentralized Applications (DApps) and to communicate with blockchain networks.

Seamless Integration with Blockchain Libraries

Node.js works effectively with several blockchain libraries. Using npm, a package manager for the JavaScript runtime environment Node.js, developers can download and utilize any of these libraries easily. Such libraries, for instance, 'bitcoinjs-lib' for Bitcoin or 'ethereumjs' for Ethereum, afford developers the capacity to build and sign transactions right inside Node.js applications before relaying them to the network.

Consider the following code snippet illustrating a simple Bitcoin transaction that uses the 'bitcoinjs-lib' library:

const bitcoin = require('bitcoinjs-lib');
const testnet = bitcoin.networks.testnet;
const keyPair = bitcoin.ECPair.makeRandom({ network: testnet });

const p2pkh = bitcoin.payments.p2pkh({ pubkey: keyPair.publicKey, network: testnet });
console.log(`BTC Testnet Address: ${p2pkh.address}`);

This example demonstrates the simplicity of creating a new Bitcoin testnet address in Node.js using the 'bitcoinjs-lib'. However, more complex operations, such as transaction aggregation and broadcast, could also be done using similar libraries, which makes Node.js powerful.

Handling Complex Decentralized Systems

Complex decentralized systems pose significant challenges that Node.js can cater to very effectively. It handles large amounts of data and high volumes of requests without blocking the main thread, thus ensuring seamless performance.

However, the developer should be aware of the common pitfall of mishandling JavaScript's asynchronous nature, causing callback hell. Below is a typical example of this error followed by a potential solution:

Incorrect Usage:

    getMoreData(a, function(b){
        getMoreAndMoreData(b, function(c){ 
            console.log('Callback Hell!');

Correct Usage:

.then(a => getMoreData(a))
.then(b => getMoreAndMoreData(b))
.then(c => console.log('No more callback hell!'))
.catch(err => console.error(err));

In the correct example, promises are used to handle asynchronous operations, which result in cleaner and more maintainable code. This adjustment becomes essential as the complexity of the application augments.

Node.js Enhancing Performance in Blockchain

Node.js is an ideal environment for crafting blockchain servers due to its non-blocking I/O operations. However, these non-blocking operations come with a caveat; the CPU heavy tasks like cryptographic computations can actually block the Node.js event loop and decrease the overall performance of your server.

To circumvent this, developers often resort to delegating such CPU-intense tasks to separate microservices, which can significantly optimize performance in the long run.

Memory Management in Node.js for Blockchain Development

Even though Node.js is adept for building high-performing blockchain applications, it might not be the most memory-efficient choice. Node.js keeps track of dynamic memory using a garbage collector. This means if objects are created and not deallocated correctly, the application could result in a memory leak.

For instance, if a global variable is not unset in an application, the memory it used could be lost until the application exits. Thus, carefulness is required to ensure that unnecessary objects are deallocated.


The pros and cons related to Node.js in blockchain development demand a deeper understanding of JavaScript, Node.js quirks, and some good programming practices. It is less about the tools you utilize and more about how you use them effectively.

Breaking Down Binance-Chain/JavaScript-SDK for Application Development

One of the prominent libraries in the blockchain space that allows JavaScript developers to exercise their craft is the @binance-chain/javascript-sdk. Built specifically for connecting with the Binance Chain, a blockchain network optimized for fast trading and DEX (Decentralized Exchange) operations, this software development kit (SDK) offers opportunities to create and manage wallets, conduct transactions, issue tokens, place orders, and more, all through JavaScript.

Performance Analysis of Binance-Chain/JavaScript-SDK

The low-level RPC calls and optimized functions of the Binance-Chian/JavaScript-sdk enable better speed and performance when interacting with the Binance Chain. The streamlined functionality doesn't only facilitate developers to perform the essential actions on the Binance Chain mainnet, testnets, or DEX but also extends a simplified integration into any JavaScript application. The SDK's lightweight design aids in ensuring memory-efficient operation without compromising performance metrics.

Stumbling Blocks and Common Mistakes

While using the Binance-Chain/JavaScript-SDK library, developers might face scenario-specific issues:

Delay in Transaction Confirmation: The network speed of the blockchain network ultimately decides the time it takes for transaction confirmation. A common mistake developers make is not preparing the application to handle this delay effectively. This mistake doesn't derive from the SDK but is a structural characteristic of blockchain applications that developers must account for.

Errors in Handling Server Responses: Server responses, especially errors from the Binance Chain, should be handled appropriately. A common mistake is not catching and treating these responses correctly, leading to unexpected application behavior.

Code Example: Creating a Wallet

Managing wallets is a key operation in any blockchain application. Here is an example of how you can create a new wallet using @binance-chain/javascript-sdk.

const bncClient = require('@binance-chain/javascript-sdk')
const privateKey = 'YOUR_PRIVATE_KEY' // should be replaced with actual private key

// Create a client
const client = new bncClient('')

// Initialize the client
client.chooseNetwork('mainnet'); // Select the mainnet network
client.setPrivateKey(privateKey); // Set your private key
client.initChain().then( () => {
    // Get account details
    client.getBalance(address).then(balance => console.log(balance)) // Log the account balance into the console

In the code snippet above, we start by importing the @binance-chain/javascript-sdk module and creating an instance of bncClient. Then, the mainnet network is chosen, the private key is set, and the chain is initialized. Finally, the account balance is fetched and logged into the console.

Can you identify what you would do differently in the above code, especially considering the best practices?

Final Thoughts

The @binance-chain/javascript-sdk marries the familiarity of JavaScript with the advances of blockchain technology. It offers a convenient and efficient path to expedite application development on the Binance Chain. However, developers need to appreciate the nuances of blockchain technology and integrate them into the application structure to avoid common pitfalls. Next on our intense examination will be the TronWeb library. Can you guess what common mistakes developers might face while using this library based on your experience with @binance-chain/javascript-sdk?

Examining Polkadot's JavaScript Library for Interoperability

The @polkadot/api JavaScript library is a well-rounded option for blockchain application development focusing on interoperability. It offers a diverse set of functionalities, promoting efficient and secure data communication between heterogeneous systems.

Standout Features

One of the primary attributes of the @polkadot/api library is its intuitive modular architecture. This enhances reusability, readability, and aids in isolating and resolving potential programming issues.

const api = await ApiPromise.create(); // Connect to Polkadot node

const chain = await api.rpc.system.chain(); // Fetch the chain name

console.log(`You are connected to ${chain}`);

In this short snippet, the ApiPromise.create() method is used to establish a connection to the Polkadot node. Then, we use the api.rpc.system.chain() function to retrieve the chain name, demonstrating how seamlessly we can request and receive data.

The @polkadot/api library also emphasizes flexibility. Developers can easily extend and enrich the existing data structures and modules to better cater to their requirements using the decorateMethod() method.

// Example of extending an existing type
const MyType = api.registry.extendType('MyType', {
  property1: 'u32',
  property2: 'String',

// Extend and enrich existing modules
const decorated = api.decorateMethod('myMethod', MyType);

In the above example, the extendType() method is used to create a custom type MyType. The decorateMethod() further extends the module by adding an enriched method myMethod.

Role in Interoperability

Interoperability, the ability of diverse systems to work in unison, is vital for blockchain technology to transcend beyond its immediate ecosystem. The @polkadot/api library plays a foundational role in achieving interoperability. The Polkadot's cross-chain messaging protocol allows diversified blockchains to communicate and interact seamlessly. => {
  console.log(`\nReceived ${events.length} events:`);

  events.forEach((record) => {
    const { event } = record;
    // Logs details of incoming events to the console
    console.log(`\n\t${event.section}:${event.method}:: `);

This code snippet showcases how @polkadot/api can facilitate interoperability. The function allows you to monitor and react to incoming events from interacting blockchains.

Potential Shortcomings and Solutions

Despite its strengths, @polkadot/api has some shortcomings. Some developers have reported performance challenges during intense data operations. However, by adequately managing memory usage and properly structuring code to optimize execution, these limitations can be circumvented.

The library also lacks comprehensive documentation, making it difficult for novice developers to utilize it fully. More experienced developers are encouraged to learn from the API's usage in the Polkadot/Substrate ecosystem, or by trying to read and understand the source code itself.

In conclusion, while it might be a bit difficult to start using @polkadot/api at the beginning, its potential for facilitating blockchain interoperability and enhancing secure communication is impressive. By understanding its key features and potential shortcomings, developers can better exploit this library for creating dynamic, interoperable blockchain applications.



The article explores various JavaScript libraries that are useful for blockchain development. It discusses the benefits of using JavaScript for blockchain development, such as its event-driven paradigm and asynchronous behavior. The article also highlights common pitfalls of using JavaScript in the blockchain context, such as floating-point precision and mutability of arrays and objects, and provides remedies for these issues.

Key takeaways from the article include:

  • JavaScript's asynchronous behavior and versatility make it well-suited for blockchain development.
  • Libraries like Web3.js, Ethers.js, Truffle Suite, and Binance-Chain/JavaScript-SDK provide powerful tools and functionalities for blockchain development.
  • Developers need to be aware of the potential pitfalls of using JavaScript in the blockchain context and use appropriate remedies to mitigate these issues.

Challenging technical task: Think about how including the Ethers.js library in your framework library can improve the performance, readability, and maintainability of your codebase in future blockchain projects. Consider the specific features and advantages of Ethers.js discussed in the article and how they can be leveraged to enhance your development process.

Don't Get Left Behind:
The Top 5 Career-Ending Mistakes Software Developers Make
FREE Cheat Sheet for Software Developers