Blockchain &amp; Web3

But how does bitcoin actually work? (3Blue1Brown)

A beautifully animated walkthrough of digital signatures, ledgers and proof of work.

youtube.com

Video

Ethereum Developer Docs

The official technical docs on the EVM, transactions, gas, accounts and smart contracts.

ethereum.org

Ethereum Whitepaper

Vitalik Buterin's original design for a general-purpose programmable blockchain.

ethereum.org

Article

Bitcoin Developer Guides

Official guides to Bitcoin's blockchain, transactions, wallets and P2P network.

developer.bitcoin.org

Mastering Bitcoin

Andreas Antonopoulos's classic technical book on Bitcoin, free to read on GitHub.

github.com

Mastering Ethereum

The companion book for Ethereum, covering the EVM, Solidity and smart contract security. Free on GitHub.

github.com

Bitcoin and Cryptocurrency Technologies (Princeton)

The Princeton textbook and course on how cryptocurrencies work, from hash functions to mining.

bitcoinbook.cs.princeton.edu

MIT 15.S12 Blockchain and Money

Gary Gensler's MIT lecture series on blockchain technology and its uses, free on OpenCourseWare.

ocw.mit.edu

Berkeley RDI Blockchain Courses

UC Berkeley's blockchain fundamentals and decentralized finance lectures, with free recordings.

rdi.berkeley.edu

CryptoZombies

Learn Solidity by building a zombie game, one interactive lesson at a time. Great first step.

cryptozombies.io

Solidity Documentation

The official language docs, with clear examples and a security considerations section.

docs.soliditylang.org

Solidity by Example

Short, runnable Solidity snippets for nearly every common pattern and language feature.

solidity-by-example.org

Cheatsheet

Cyfrin Updraft

Free, in-depth courses by Patrick Collins on Solidity, Foundry, DeFi and smart contract auditing.

updraft.cyfrin.io

Alchemy University

A free Ethereum developer bootcamp covering cryptography, Solidity and dapp building.

alchemy.com

Patrick Collins Solidity Course (freeCodeCamp)

A famous 32-hour video course on blockchain, Solidity and full-stack web3 with JavaScript.

youtube.com

Video

Speedrun Ethereum

Build a series of hands-on dapp challenges with Scaffold-ETH and get feedback from the community.

speedrunethereum.com

Scaffold-ETH 2

An open-source starter kit for building Ethereum dapps quickly with Next.js and Foundry or Hardhat.

scaffoldeth.io

Remix IDE

A browser-based IDE to write, compile, deploy and debug Solidity contracts with nothing to install.

remix.ethereum.org

Foundry

Docs for Foundry, the fast Rust-based toolkit for writing, testing and deploying Solidity contracts.

getfoundry.sh

Hardhat

Docs for Hardhat, the popular JavaScript and TypeScript environment for Ethereum development.

hardhat.org

OpenZeppelin Contracts

Audited, reusable contract building blocks like ERC-20, ERC-721 and access control.

docs.openzeppelin.com

Ethers.js

A compact JavaScript library for talking to Ethereum from your app or scripts.

docs.ethers.org

Viem

A modern, typed TypeScript library for interacting with Ethereum.

viem.sh

Ethereum Improvement Proposals

The official list of EIPs and ERCs, the standards behind tokens, NFTs and protocol upgrades.

eips.ethereum.org

EVM Codes

An interactive reference for every EVM opcode, with gas costs and a playground.

evm.codes

Cheatsheet

Ethernaut

OpenZeppelin's wargame where each level is a vulnerable contract you have to hack.

ethernaut.openzeppelin.com

Damn Vulnerable DeFi

Offensive security challenges based on real DeFi bugs like flash loans and oracle manipulation.

damnvulnerabledefi.xyz

Capture the Ether

A classic set of Ethereum security puzzles that teach common smart contract pitfalls.

capturetheether.com

SWC Registry

A catalogue of known smart contract weaknesses with explanations and example code.

swcregistry.io

Smart Contract Security Field Guide

A practical guide to common smart contract vulnerabilities and how to prevent them.

scsfg.io

Guide

Solcurity Standard

A widely used checklist for reviewing Solidity code for security and quality.

github.com

Cheatsheet

Slither

Trail of Bits' static analyzer that finds bugs in Solidity code automatically.

github.com

Building Secure Contracts

Trail of Bits' guidelines and tool tutorials for writing and testing secure smart contracts.

secure-contracts.com

Guide

Code4rena

Competitive audit contests where you can read real reports and practice finding bugs.

code4rena.com

Solana Developer Docs

Official docs on Solana's accounts, programs and transactions, with quickstarts.

solana.com

Anchor

The most popular framework for writing Solana programs in Rust.

anchor-lang.com

The Rust Book

The official Rust book. Learn Rust here before building on Solana or Polkadot.

doc.rust-lang.org

Polkadot SDK Docs

Official developer docs for building on Polkadot and with the Substrate-based Polkadot SDK.

docs.polkadot.com

Cosmos SDK Docs

Docs for the Cosmos SDK, a Go framework for building your own application-specific blockchain.

docs.cosmos.network

Chainlink Docs

Learn how oracles bring off-chain data like prices and randomness into smart contracts.

docs.chain.link

IPFS Docs

Learn content-addressed, peer-to-peer file storage, often used alongside blockchains.

docs.ipfs.tech

The Graph Docs

Index and query blockchain data with GraphQL subgraphs.

thegraph.com

Crypto 101

A free introductory book on cryptography for programmers, from XOR to public keys.

crypto101.io

Cryptography I (Stanford, Coursera)

Dan Boneh's famous course on the cryptographic primitives blockchains are built on.

coursera.org

A Graduate Course in Applied Cryptography

Boneh and Shoup's free, rigorous textbook for when you want the math behind the primitives.

toc.cryptobook.us

Etherscan

The main Ethereum block explorer. Inspect transactions, addresses and verified contract code.

etherscan.io

Sepolia Etherscan

Explorer for the Sepolia testnet, where you deploy and test contracts for free.

sepolia.etherscan.io

mempool.space

An open-source Bitcoin explorer that visualizes blocks, fees and the mempool live.

mempool.space

Solana Explorer

The official explorer for Solana transactions, accounts and programs.

explorer.solana.com

MetaMask Docs

Connect your dapp to the most widely used Ethereum wallet.

docs.metamask.io

ETHGlobal

Online and in-person Ethereum hackathons with workshops, mentors and a showcase of past projects.

ethglobal.com

ETHIndia

India's largest Ethereum hackathon, held yearly in Bengaluru.

ethindia.co

Devfolio

India's hackathon platform, home to many web3 and general student hackathons.

devfolio.co

Ethereum Stack Exchange

Q&A site for Ethereum developers. Search here when a contract or tool misbehaves.

ethereum.stackexchange.com

Bitcoin Stack Exchange

Q&A site for Bitcoin developers and enthusiasts.

bitcoin.stackexchange.com

Ethereum Research

The forum where protocol researchers discuss scaling, consensus and future upgrades.

ethresear.ch

Awesome Ethereum Security

A curated list of smart contract security tools, guides and CTFs.

github.com

Repo

Awesome Solidity

A curated list of Solidity resources, libraries and tools.

github.com

Repo

Blockchain Developer Roadmap

A visual roadmap of what to learn to become a blockchain developer.

roadmap.sh

Roadmap

Ethereum Foundation Blog

Official announcements and research updates on Ethereum's protocol and ecosystem.

blog.ethereum.org

Article

Zero Knowledge Podcast

Technical interviews on zero-knowledge proofs, cryptography and decentralized systems.

zeroknowledge.fm

Podcast

ZK MOOC (Berkeley)

A free university course on zero-knowledge proofs, with lectures from leading researchers.

zk-learning.org