Guide · Open source

How to use Julia: install, run the REPL and build from source

Updated 2026-10-29 · written with AI from the project's own documentation and checked against our catalogue data

Julia is a high-level, high-performance dynamic language for technical computing, meaning math, data analysis and scientific work. This guide explains how to install it, start its interactive prompt, and set up an editor. It also covers building the language from its source repository for readers who want to go that route.

JuliaJuliaLang/julia · ★ 49.2k · MIT Install options & downloads

Quick start

1Install with juliaup. Follow the instructions at julialang.org/downloads to install juliaup, which installs the latest stable Julia.
2Open a terminal. Open a terminal or command prompt. On Windows, a modern terminal such as Windows Terminal is recommended.
3Start the REPL. Run julia to see the banner and the interactive prompt.
4Try an expression. Type an expression at the prompt and press Enter to see the result.
5Pick an editor. Choose an editor or IDE, such as VS Code with the julia-vscode plugin, or a notebook option like IJulia or Pluto.jl.
6Build from source only if needed. For developers, clone the repository, check out a stable tag, run make, and then run make testall.

Install Julia with juliaup

The recommended way to install Julia is to use juliaup, which installs the latest stable julia for you and helps keep it up to date. It can also install and run different Julia versions at the same time. Instructions are on the official downloads page at julialang.org.

If you want a specific binary, the Manual Downloads page lists them. The downloads page also describes the tiers of support for each operating system and platform.

Use juliaup for most installs
Use Manual Downloads only if you need a specific binary
Avoid OS package manager copies: the Julia project does not maintain or endorse them, and they may be outdated or broken

Start Julia and use the interactive prompt

If the install worked, running julia in a terminal or command prompt shows a Julia banner and an interactive prompt. You type expressions there and Julia evaluates them.

The manual has a getting started section, and the REPL section of the docs describes the prompt in more detail.

Open a terminal or command prompt
Run julia to get the banner and prompt
Enter expressions and press Enter to see results

julia

Choose an editor or IDE

Julia has editing support for several widely used editors, including Emacs, Vim and Sublime Text. Users who prefer an IDE are recommended to use VS Code with the julia-vscode plugin.

For notebooks, Jupyter support is available through the IJulia package, and Pluto notebooks are provided by the Pluto.jl package.

On Windows, the project highly recommends running Julia in a modern terminal such as Windows Terminal from the Microsoft Store.

VS Code with julia-vscode
Emacs, Vim or Sublime Text with the editor support projects
Jupyter via IJulia, or Pluto.jl for notebooks

Build Julia from source (optional)

Building Julia from this repository is for developers who want to modify the language or study its internals. Most people should install the official binaries instead. First install the required build tools and external libraries, described in the build documentation.

The build needs 2GiB of free disk space and about 4GiB of virtual memory. Make sure no parent directory of the build directory has spaces or shell meta-characters such as $ or : in its name, because the build will fail otherwise.

Clone the repository, change into the julia directory, and build. By default you build the latest unstable version. Most users should check out the most recent stable release tag, replacing [tag] with the tag you want.

Requires about 2GiB disk and roughly 4GiB virtual memory
Replace [tag] with a stable release tag from the releases page
Run ./julia from the julia directory after the build

git clone https://github.com/JuliaLang/julia.git
cd julia
git checkout [tag]
make
./julia

Run the test suite

After building, run the tests from the julia directory. If the test output lists a series of running tests and completes without error, the build is working and you can start using Julia.

Detailed build instructions are in the build documentation linked from the repository.

make testall

Where Julia stores files and how to uninstall

By default Julia installs nothing outside the directory it was cloned into and ~/.julia. Julia and the vast majority of Julia packages can be removed by deleting these two directories.

~/.julia

What people use it for

Numerical and scientific computing with readable syntax
Data analysis and technical calculations at the interactive prompt
Working in Jupyter notebooks through IJulia or in Pluto notebooks through Pluto.jl
Building or modifying the Julia language itself from its source code
Learning technical computing with a free, MIT-licensed tool

Frequently asked questions

Is Julia free to use?

Yes. The repository is licensed under the MIT licence, and the source code is public on GitHub. The README does not describe pricing for other offerings, so check the official site for anything beyond the language.

How do I install Julia?

The recommended method is juliaup, which installs the latest stable Julia and can keep it updated. Instructions are at julialang.org/downloads, and specific binaries are on the Manual Downloads page.

Should I install Julia from my Linux package manager?

The README says that OS package manager versions are neither maintained nor endorsed by the Julia project, and may be outdated or broken. It recommends the official binaries instead.

What do I need to build Julia from source?

You need the required build tools and external libraries listed in the build documentation, about 2GiB of free disk space, and roughly 4GiB of virtual memory. Build paths must not contain spaces or characters such as $ or :.

How do I check that Julia works?

If you built from source, run make testall from the julia directory and check that the tests complete without error. For a binary install, running julia should show the banner and an interactive prompt.

How does Julia compare with Python, R, MATLAB or GNU Octave?

The README does not compare Julia with these tools, so this guide cannot make a claim about them. It does note that the language has a large package ecosystem, but it does not compare package counts with other languages.

New agent skills, repos and AI tools — every week

The best new skills and open-source projects, the fastest-growing repos, and one free prompt. Five minutes to read. Unsubscribe anytime.

Our verdict

Julia suits scientists, engineers and students who write numerical code and want readable syntax with good speed, and it is free under the MIT licence. Developers who want to change the language itself can build it from this repository. If you need a general-purpose language with a very large ecosystem, or you have limited disk space and memory, consider another option.

Install options & downloads