Incremental Builds #

Incremental builds perform a partial build operating only on files that have changed to improve build times when doing local development.

Incremental builds via the command line flag --incremental have been available without much fanfare in Eleventy for a few versions now. Let’s check in on what the current capabilities of incremental builds are and the plans to improve:

Passthrough Copy #

• Incremental passthrough copy (✅ available in 0.11.0+) uses the following rules:
  • Only copy a passthrough copy file when it actively changed. Don’t run a template build if only a passthrough copy file has changed.
  • If a template has changed, don’t copy the passthrough copy files.
  • Some discussion about making this behavior default at Issue #1109. Personally, I’m still on the fence here.

Configuration File #

If you create/update your Eleventy configuration file, a full build will run.

Templates #

• If you create/update a template file, Eleventy will run the build for that file and only that file.
• If the created/updated file is in your Includes or Layouts directories, a full build will run.
• This feature is also exposed as part of the API for Custom template extensions via the isIncrementalMatch function (✅ available in 1.0.0+).

🗓 To Do #

Templates #

• Smarter dependency map between templates:
  • Eleventy layouts
  • Publishing into Collections and consuming from Collections
  • 11ty.js JavaScript dependencies
  • Global/directory/template Data file usage mapped to templates
  • Stretch goal: Pagination-level incremental that operates on a subset of data
  • Stretch goal: Work with include/extend/import/macro specific features of template languages.

Smarter Template Language Support #

• Liquid
• Nunjucks

Cold Start #

Currently incremental does a full build to start out to provide a fresh starting point to work from. Improvements will save the state of the build to a cache for faster cold starts. Issue #984