Solidity is an object-oriented, high-level language for implementing smart contracts. Smart contracts are programs which govern the behaviour of accounts within the Ethereum state.
Solidity is statically typed, supports inheritance, libraries and complex user-defined types among other features.
With Solidity you can create contracts for uses such as voting, crowdfunding, blind auctions, and multi-signature wallets.
When deploying contracts, you should use the latest released version of Solidity. Apart from exceptional cases, only the latest version receives security fixes. Furthermore, breaking changes as well as new features are introduced regularly. We currently use a 0.y.z version number to indicate this fast pace of change.
Solidity recently released the 0.8.x version that introduced a lot of breaking changes. Make sure you read the full list.
Ideas for improving Solidity or this documentation are always welcome, read our contributors guide for more details.
You can download this documentation as PDF, HTML or Epub by clicking on the versions flyout menu in the bottom-left corner and selecting the preferred download format.
1. Understand the Smart Contract Basics
If you are new to the concept of smart contracts we recommend you to get started by digging into the “Introduction to Smart Contracts” section, which covers:
A simple example smart contract written in Solidity.
2. Get to Know Solidity
Once you are accustomed to the basics, we recommend you read the “Solidity by Example” and “Language Description” sections to understand the core concepts of the language.
3. Install the Solidity Compiler
There are various ways to install the Solidity compiler, simply choose your preferred option and follow the steps outlined on the installation page.
You can try out code examples directly in your browser with the Remix IDE. Remix is a web browser based IDE that allows you to write, deploy and administer Solidity smart contracts, without the need to install Solidity locally.
As humans write software, it can have bugs. You should follow established software development best-practices when writing your smart contracts. This includes code review, testing, audits, and correctness proofs. Smart contract users are sometimes more confident with code than their authors, and blockchains and smart contracts have their own unique issues to watch out for, so before working on production code, make sure you read the Security Considerations section.
4. Learn More
If you want to learn more about building decentralized applications on Ethereum, the Ethereum Developer Resources can help you with further general documentation around Ethereum, and a wide selection of tutorials, tools and development frameworks.
Community contributors help translate this documentation into several languages. Note that they have varying degrees of completeness and up-to-dateness. The English version stands as a reference.
You can switch between languages by clicking on the flyout menu in the bottom-left corner and selecting the preferred language.
We set up a GitHub organization and translation workflow to help streamline the community efforts. Please refer to the translation guide in the solidity-docs org for information on how to start a new language or contribute to the community translations.
- Introduction to Smart Contracts
- Installing the Solidity Compiler
- Solidity by Example
- Layout of a Solidity Source File
- Structure of a Contract
- Units and Globally Available Variables
- Expressions and Control Structures
- Inline Assembly
- Language Grammar
- Layout of State Variables in Storage
- Layout in Memory
- Layout of Call Data
- Cleaning Up Variables
- Source Mappings
- The Optimizer
- Contract Metadata
- Contract ABI Specification
- Solidity v0.5.0 Breaking Changes
- Solidity v0.6.0 Breaking Changes
- Solidity v0.7.0 Breaking Changes
- Solidity v0.8.0 Breaking Changes
- NatSpec Format
- Security Considerations
- SMTChecker and Formal Verification
- Import Path Resolution
- Style Guide
- Common Patterns
- List of Known Bugs
- Solidity Brand Guide
- Language Influences