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.. index:: ! installing

Installing the Solidity Compiler

Versioning

Solidity versions follow Semantic Versioning. In addition, patch level releases with major release 0 (i.e. 0.x.y) will not contain breaking changes. That means code that compiles with version 0.x.y can be expected to compile with 0.x.z where z > y.

In addition to releases, we provide nightly development builds with the intention of making it easy for developers to try out upcoming features and provide early feedback. Note, however, that while the nightly builds are usually very stable, they contain bleeding-edge code from the development branch and are not guaranteed to be always working. Despite our best efforts, they might contain undocumented and/or broken changes that will not become a part of an actual release. They are not meant for production use.

When deploying contracts, you should use the latest released version of Solidity. This is because breaking changes, as well as new features and bug fixes are introduced regularly. We currently use a 0.x version number to indicate this fast pace of change.

Remix

We recommend Remix for small contracts and for quickly learning Solidity.

Access Remix online, you do not need to install anything. If you want to use it without connection to the Internet, go to https://github.com/ethereum/remix-live/tree/gh-pages and download the .zip file as explained on that page. Remix is also a convenient option for testing nightly builds without installing multiple Solidity versions.

Further options on this page detail installing commandline Solidity compiler software on your computer. Choose a commandline compiler if you are working on a larger contract or if you require more compilation options.

npm / Node.js

Use npm for a convenient and portable way to install solcjs, a Solidity compiler. The solcjs program has fewer features than the ways to access the compiler described further down this page. The :ref:`commandline-compiler` documentation assumes you are using the full-featured compiler, solc. The usage of solcjs is documented inside its own repository.

Note: The solc-js project is derived from the C++ solc by using Emscripten which means that both use the same compiler source code. solc-js can be used in JavaScript projects directly (such as Remix). Please refer to the solc-js repository for instructions.

npm install -g solc

Note

The commandline executable is named solcjs.

The commandline options of solcjs are not compatible with solc and tools (such as geth) expecting the behaviour of solc will not work with solcjs.

Docker

Docker images of Solidity builds are available using the solc image from the ethereum organisation. Use the stable tag for the latest released version, and nightly for potentially unstable changes in the develop branch.

The Docker image runs the compiler executable, so you can pass all compiler arguments to it. For example, the command below pulls the stable version of the solc image (if you do not have it already), and runs it in a new container, passing the --help argument.

docker run ethereum/solc:stable --help

You can also specify release build versions in the tag, for example, for the 0.5.4 release.

docker run ethereum/solc:0.5.4 --help

To use the Docker image to compile Solidity files on the host machine mount a local folder for input and output, and specify the contract to compile. For example.

docker run -v /local/path:/sources ethereum/solc:stable -o /sources/output --abi --bin /sources/Contract.sol

You can also use the standard JSON interface (which is recommended when using the compiler with tooling). When using this interface it is not necessary to mount any directories as long as the JSON input is self-contained (i.e. it does not refer to any external files that would have to be :ref:`loaded by the import callback <initial-vfs-content-standard-json-with-import-callback>`).

docker run ethereum/solc:stable --standard-json < input.json > output.json

Linux Packages

Binary packages of Solidity are available at solidity/releases.

We also have PPAs for Ubuntu, you can get the latest stable version using the following commands:

sudo add-apt-repository ppa:ethereum/ethereum
sudo apt-get update
sudo apt-get install solc

The nightly version can be installed using these commands:

sudo add-apt-repository ppa:ethereum/ethereum
sudo add-apt-repository ppa:ethereum/ethereum-dev
sudo apt-get update
sudo apt-get install solc

Furthermore, some Linux distributions provide their own packages. These packages are not directly maintained by us, but usually kept up-to-date by the respective package maintainers.

For example, Arch Linux has packages for the latest development version:

pacman -S solidity

There is also a snap package, however, it is currently unmaintained. It is installable in all the supported Linux distros. To install the latest stable version of solc:

sudo snap install solc

If you want to help testing the latest development version of Solidity with the most recent changes, please use the following:

sudo snap install solc --edge

Note

The solc snap uses strict confinement. This is the most secure mode for snap packages but it comes with limitations, like accessing only the files in your /home and /media directories. For more information, go to Demystifying Snap Confinement.

macOS Packages

We distribute the Solidity compiler through Homebrew as a build-from-source version. Pre-built bottles are currently not supported.

brew update
brew upgrade
brew tap ethereum/ethereum
brew install solidity

To install the most recent 0.4.x / 0.5.x version of Solidity you can also use brew install solidity@4 and brew install solidity@5, respectively.

If you need a specific version of Solidity you can install a Homebrew formula directly from Github.

View solidity.rb commits on Github.

Copy the commit hash of the version you want and check it out on your machine.

git clone https://github.com/ethereum/homebrew-ethereum.git
cd homebrew-ethereum
git checkout <your-hash-goes-here>

Install it using brew:

brew unlink solidity
# eg. Install 0.4.8
brew install solidity.rb

Static Binaries

We maintain a repository containing static builds of past and current compiler versions for all supported platforms at solc-bin. This is also the location where you can find the nightly builds.

The repository is not only a quick and easy way for end users to get binaries ready to be used out-of-the-box but it is also meant to be friendly to third-party tools:

  • The content is mirrored to https://binaries.soliditylang.org where it can be easily downloaded over HTTPS without any authentication, rate limiting or the need to use git.
  • Content is served with correct Content-Type headers and lenient CORS configuration so that it can be directly loaded by tools running in the browser.
  • Binaries do not require installation or unpacking (with the exception of older Windows builds bundled with necessary DLLs).
  • We strive for a high level of backwards-compatibility. Files, once added, are not removed or moved without providing a symlink/redirect at the old location. They are also never modified in place and should always match the original checksum. The only exception would be broken or unusable files with a potential to cause more harm than good if left as is.
  • Files are served over both HTTP and HTTPS. As long as you obtain the file list in a secure way (via git, HTTPS, IPFS or just have it cached locally) and verify hashes of the binaries after downloading them, you do not have to use HTTPS for the binaries themselves.

The same binaries are in most cases available on the Solidity release page on Github. The difference is that we do not generally update old releases on the Github release page. This means that we do not rename them if the naming convention changes and we do not add builds for platforms that were not supported at the time of release. This only happens in solc-bin.

The solc-bin repository contains several top-level directories, each representing a single platform. Each one contains a list.json file listing the available binaries. For example in emscripten-wasm32/list.json you will find the following information about version 0.7.4:

{
  "path": "solc-emscripten-wasm32-v0.7.4+commit.3f05b770.js",
  "version": "0.7.4",
  "build": "commit.3f05b770",
  "longVersion": "0.7.4+commit.3f05b770",
  "keccak256": "0x300330ecd127756b824aa13e843cb1f43c473cb22eaf3750d5fb9c99279af8c3",
  "sha256": "0x2b55ed5fec4d9625b6c7b3ab1abd2b7fb7dd2a9c68543bf0323db2c7e2d55af2",
  "urls": [
    "bzzr://16c5f09109c793db99fe35f037c6092b061bd39260ee7a677c8a97f18c955ab1",
    "dweb:/ipfs/QmTLs5MuLEWXQkths41HiACoXDiH8zxyqBHGFDRSzVE5CS"
  ]
}

This means that:

Warning

Due to the strong backwards compatibility requirement the repository contains some legacy elements but you should avoid using them when writing new tools:

  • Use emscripten-wasm32/ (with a fallback to emscripten-asmjs/) instead of bin/ if you want the best performance. Until version 0.6.1 we only provided asm.js binaries. Starting with 0.6.2 we switched to WebAssembly builds with much better performance. We have rebuilt the older versions for wasm but the original asm.js files remain in bin/. The new ones had to be placed in a separate directory to avoid name clashes.
  • Use emscripten-asmjs/ and emscripten-wasm32/ instead of bin/ and wasm/ directories if you want to be sure whether you are downloading a wasm or an asm.js binary.
  • Use list.json instead of list.js and list.txt. The JSON list format contains all the information from the old ones and more.
  • Use https://binaries.soliditylang.org instead of https://solc-bin.ethereum.org. To keep things simple we moved almost everything related to the compiler under the new soliditylang.org domain and this applies to solc-bin too. While the new domain is recommended, the old one is still fully supported and guaranteed to point at the same location.

Warning

The binaries are also available at https://ethereum.github.io/solc-bin/ but this page stopped being updated just after the release of version 0.7.2, will not receive any new releases or nightly builds for any platform and does not serve the new directory structure, including non-emscripten builds.

If you are using it, please switch to https://binaries.soliditylang.org, which is a drop-in replacement. This allows us to make changes to the underlying hosting in a transparent way and minimize disruption. Unlike the ethereum.github.io domain, which we do not have any control over, binaries.soliditylang.org is guaranteed to work and maintain the same URL structure in the long-term.

Building from Source

Prerequisites - All Operating Systems

The following are dependencies for all builds of Solidity:

Software Notes
CMake (version 3.21.3+ on Windows, 3.13+ otherwise) Cross-platform build file generator.
Boost (version 1.77 on Windows, 1.65+ otherwise) C++ libraries.
Git Command-line tool for retrieving source code.
z3 (version 4.8.16+, Optional) For use with SMT checker.
cvc4 (Optional) For use with SMT checker.

Note

Solidity versions prior to 0.5.10 can fail to correctly link against Boost versions 1.70+. A possible workaround is to temporarily rename <Boost install path>/lib/cmake/Boost-1.70.0 prior to running the cmake command to configure solidity.

Starting from 0.5.10 linking against Boost 1.70+ should work without manual intervention.

Note

The default build configuration requires a specific Z3 version (the latest one at the time the code was last updated). Changes introduced between Z3 releases often result in slightly different (but still valid) results being returned. Our SMT tests do not account for these differences and will likely fail with a different version than the one they were written for. This does not mean that a build using a different version is faulty. If you pass -DSTRICT_Z3_VERSION=OFF option to CMake, you can build with any version that satisfies the requirement given in the table above. If you do this, however, please remember to pass the --no-smt option to scripts/tests.sh to skip the SMT tests.

Note

By default the build is performed in pedantic mode, which enables extra warnings and tells the compiler to treat all warnings as errors. This forces developers to fix warnings as they arise, so they do not accumulate "to be fixed later". If you are only interested in creating a release build and do not intend to modify the source code to deal with such warnings, you can pass -DPEDANTIC=OFF option to CMake to disable this mode. Doing this is not recommended for general use but may be necessary when using a toolchain we are not testing with or trying to build an older version with newer tools. If you encounter such warnings, please consider reporting them.

Minimum Compiler Versions

The following C++ compilers and their minimum versions can build the Solidity codebase:

Prerequisites - macOS

For macOS builds, ensure that you have the latest version of Xcode installed. This contains the Clang C++ compiler, the Xcode IDE and other Apple development tools that are required for building C++ applications on OS X. If you are installing Xcode for the first time, or have just installed a new version then you will need to agree to the license before you can do command-line builds:

sudo xcodebuild -license accept

Our OS X build script uses the Homebrew package manager for installing external dependencies. Here's how to uninstall Homebrew, if you ever want to start again from scratch.

Prerequisites - Windows

You need to install the following dependencies for Windows builds of Solidity:

Software Notes
Visual Studio 2019 Build Tools C++ compiler
Visual Studio 2019 (Optional) C++ compiler and dev environment.
Boost (version 1.77) C++ libraries.

If you already have one IDE and only need the compiler and libraries, you could install Visual Studio 2019 Build Tools.

Visual Studio 2019 provides both IDE and necessary compiler and libraries. So if you have not got an IDE and prefer to develop Solidity, Visual Studio 2019 may be a choice for you to get everything setup easily.

Here is the list of components that should be installed in Visual Studio 2019 Build Tools or Visual Studio 2019:

  • Visual Studio C++ core features
  • VC++ 2019 v141 toolset (x86,x64)
  • Windows Universal CRT SDK
  • Windows 8.1 SDK
  • C++/CLI support

We have a helper script which you can use to install all required external dependencies:

scripts\install_deps.ps1

This will install boost and cmake to the deps subdirectory.

Clone the Repository

To clone the source code, execute the following command:

git clone --recursive https://github.com/ethereum/solidity.git
cd solidity

If you want to help developing Solidity, you should fork Solidity and add your personal fork as a second remote:

git remote add personal [email protected]:[username]/solidity.git

Note

This method will result in a prerelease build leading to e.g. a flag being set in each bytecode produced by such a compiler. If you want to re-build a released Solidity compiler, then please use the source tarball on the github release page:

https://github.com/ethereum/solidity/releases/download/v0.X.Y/solidity_0.X.Y.tar.gz

(not the "Source code" provided by github).

Command-Line Build

Be sure to install External Dependencies (see above) before build.

Solidity project uses CMake to configure the build. You might want to install ccache to speed up repeated builds. CMake will pick it up automatically. Building Solidity is quite similar on Linux, macOS and other Unices:

mkdir build
cd build
cmake .. && make

or even easier on Linux and macOS, you can run:

#note: this will install binaries solc and soltest at usr/local/bin
./scripts/build.sh

Warning

BSD builds should work, but are untested by the Solidity team.

And for Windows:

mkdir build
cd build
cmake -G "Visual Studio 16 2019" ..

In case you want to use the version of boost installed by scripts\install_deps.ps1, you will additionally need to pass -DBoost_DIR="deps\boost\lib\cmake\Boost-*" and -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded as arguments to the call to cmake.

This should result in the creation of solidity.sln in that build directory. Double-clicking on that file should result in Visual Studio firing up. We suggest building Release configuration, but all others work.

Alternatively, you can build for Windows on the command-line, like so:

cmake --build . --config Release

CMake Options

If you are interested what CMake options are available run cmake .. -LH.

SMT Solvers

Solidity can be built against SMT solvers and will do so by default if they are found in the system. Each solver can be disabled by a cmake option.

Note: In some cases, this can also be a potential workaround for build failures.

Inside the build folder you can disable them, since they are enabled by default:

# disables only Z3 SMT Solver.
cmake .. -DUSE_Z3=OFF

# disables only CVC4 SMT Solver.
cmake .. -DUSE_CVC4=OFF

# disables both Z3 and CVC4
cmake .. -DUSE_CVC4=OFF -DUSE_Z3=OFF

The Version String in Detail

The Solidity version string contains four parts:

  • the version number
  • pre-release tag, usually set to develop.YYYY.MM.DD or nightly.YYYY.MM.DD
  • commit in the format of commit.GITHASH
  • platform, which has an arbitrary number of items, containing details about the platform and compiler

If there are local modifications, the commit will be postfixed with .mod.

These parts are combined as required by SemVer, where the Solidity pre-release tag equals to the SemVer pre-release and the Solidity commit and platform combined make up the SemVer build metadata.

A release example: 0.4.8+commit.60cc1668.Emscripten.clang.

A pre-release example: 0.4.9-nightly.2017.1.17+commit.6ecb4aa3.Emscripten.clang

Important Information About Versioning

After a release is made, the patch version level is bumped, because we assume that only patch level changes follow. When changes are merged, the version should be bumped according to SemVer and the severity of the change. Finally, a release is always made with the version of the current nightly build, but without the prerelease specifier.

Example:

  1. The 0.4.0 release is made.
  2. The nightly build has a version of 0.4.1 from now on.
  3. Non-breaking changes are introduced --> no change in version.
  4. A breaking change is introduced --> version is bumped to 0.5.0.
  5. The 0.5.0 release is made.

This behaviour works well with the :ref:`version pragma <version_pragma>`.