Debug Mode

Having trouble? Want to see what Eleventy is doing behind the scenes? Use DEBUG mode. We’re taking advantage of the excellent debug package for this.

debug will tell you exactly what directories Eleventy is using for data, includes, input, and output. It’ll tell you what search globs it uses to find your templates and what templates it finds. If you’re having trouble, enable this.

You can enable this feature by using the DEBUG environment variable. To do this we add some text before the command we use to run Eleventy.

Commands

The commands below assume that Eleventy is installed locally (recommended) but you can learn more about the difference between Local and Global installation.

macOS or Linux (et al)

DEBUG=Eleventy* npx @11ty/eleventy

Cross Platform

Use the cross-env package to compatibly set your environment variables cross-platform.

npm install cross-env

Now add an npm script in your package.json, unlocking npm run debug:

{
	"scripts": {
		"debug": "cross-env DEBUG=Eleventy* npx @11ty/eleventy"
	}
}

Windows

Read more about Windows environment variables.

cmd.exe

set DEBUG=Eleventy* & npx @11ty/eleventy

Powershell (default in VS Code)

$env:DEBUG="Eleventy*"; npx @11ty/eleventy

Learn More

Read more at the debug package documentation.

Try with --dryrun

Works great with --dryrun if you want to run Eleventy but not actually write any files.

View all messages

The commands above limit the messages from debug to Eleventy specific things with DEBUG=Eleventy* but you can view all of the messages from any dependency with DEBUG=*.

Analyze Performance

Read more about how to use debug to analyze the performance of your Eleventy build.

Debug individual variables

In addition to using debug, you can use the global filter log to console.log anything from inside a template file.