How to download and install Deno on Mac

Before you start

Deno is a single program with no external dependencies. Its Mac builds need macOS 12 or later and run on Apple Silicon and Intel. The install script picks the right one by itself.

The command below is from Deno’s official documentation at docs.deno.com. Don’t run install commands copied from other sites.

Install Deno with one command

1. Open Terminal: Applications › Utilities › Terminal, or press Command-Space and type Terminal.
2. Copy the command below, paste it into Terminal and press Return.
3. The script puts Deno in ~/.deno/bin and offers to edit your shell configuration so Terminal finds deno. Accept it.
4. Open a new Terminal window so it picks up the change.

Check and update Deno

In the new Terminal window, check that Deno runs:

• Updates. If you installed Deno with the script, deno upgrade updates it. If you installed it with Homebrew, use brew upgrade deno instead.
• Cache. Deno keeps downloaded dependencies and compiled files in ~/Library/Caches/deno. deno info shows the folder in use, and deno clean empties it.

If Deno doesn’t work

• «command not found: deno». Open a new Terminal window: the script changes your shell configuration, and open windows don’t see it. If it still fails, check that ~/.deno/bin is listed by echo $PATH.
• Deno fails on an older Mac. Check your macOS version in About This Mac: Deno needs macOS 12 or later.
• Two copies of Deno. If you installed Deno both with the script and with Homebrew, which deno shows which one runs. Keep one of them.
• Start over. To remove Deno installed with the script, run deno clean, delete the ~/.deno folder and remove the line with .deno/env from ~/.zshrc, then install it again.

Alternatives to Deno

• Node.jsThe standard JavaScript runtime most projects use.
• BunA fast runtime and package manager in one.