How to open a .jl file (Windows, Mac, Linux)

Q: Why can't I open my .jl file?

Usually your computer lacks an app that understands Julia. Install one of the apps listed here, or convert the file to a more common format.

A .jl file is a Julia Source File. If double-clicking does nothing, your computer simply does not have an app that reads Julia yet. Here is how to fix that on each operating system, using free software wherever possible.

Open a .jl file step by step

Confirm the file really is a .jl. Drop it into the WhatFileType file identifier, which reads its signature without uploading anything.
On Windows, open it with VS Code (Julia) or Julia REPL.
On Mac, use VS Code (Julia) or Julia REPL.
On Linux, try VS Code (Julia) or Julia REPL.
Still stuck? Search for a dedicated Julia viewer.

Best apps to open .jl files

Windows

VS Code (Julia)
Julia REPL
any text editor

macOS

VS Code (Julia)
Julia REPL
any text editor

Linux

VS Code (Julia)
Julia REPL
any text editor

Before you open it: Caution. A .jl file is program source. Running it executes its code; review unfamiliar files first.

Frequently asked questions

Why can't I open my .jl file?

Almost always because no installed app understands Julia. Install one of the apps above, or convert the file to a format your existing software already reads.

How do I run a .jl file?

With Julia installed, run julia file.jl from a terminal, or execute it in the Julia REPL or VS Code.

Is Julia faster than Python?

For heavy numerical work, usually yes: Julia's just-in-time compilation approaches C speed, while keeping a high-level syntax. Python often relies on C libraries to match it.