Builds and Previews
Every branch in a Pages-enabled GitHub repo is built by Pages with a site preview.
Site preview links will auto-generate within pull requests. To see them, scroll to the bottom of your pull request and click “show all checks”, then click on “details” to the right of the Pages check. The site preview is only available after a build reports completion, usually within a few minutes.
You can also find links to site previews in the “GitHub Branches” page after logging into Pages.
For security reasons, site previews are unavailable with pull requests from forked repositories.
Builds and Logs
Build history and logs for every build are available in the Pages web application. Note: build logs will only be available for 180 days after the build completes.