Preview your static websites built with CircleCI before making them live. Use it to check your plain static or Jekyll-generated websites before you make them live to Github Pages or to your own server. Requires configured and working CircleCI artifacts.

Written by Michal Migurski with Mick Thompson, © 2013-2015 Code for America and © 2016 Mapzen.

You can view the source code for Precog on GitHub at

No Doubt The Precogs Have Already Seen This…

  1. Preview pages in Precog by adding your Github account name and repository name to a Precog URL:<account>/<repo>/

    Example showing the Mapzen website:

  2. To view a commit or branch other than master, add the ref to the end:<account>/<repo>/<ref>/

    Example showing a single Mapzen website commit:

  3. To view a specific file or directory, add it after the ref:<account>/<repo>/<ref>/wow/such-path.html

    Example of the Mapzen Vector Tiles project page:

Private Repositories

Precog will ask for access to your Github account to preview private repositories. You can revoke Precog’s access via your Github Applications page. Precog will keep a copy of each private repository you preview for an unknown period of time.