Fundraise Up's checkout experience avoids classic donation form pitfalls with regards to SEO, and provides several advantages over redirect-based solutions.
Prolongs time on page
Opening the Fundraise Up donation checkout doesn't necessitate opening a separate donation page, thus increasing time of page, a metric many SEOs use to determine site relevance.
Opening the Fundraise Up donation checkout does not transfer donors to other domains in the majority of cases, which keeps your relevance score high.
Avoids page-load errors
As opening the Fundraise Up donation checkout doesn't necessitate opening a separate donation page, the risk of 404 and 301 errors is eliminated.
Avoids popup penalties
Fundraise Up's donation checkout is a triggered pop-up, not an automatic one. Only automatic popups are penalized by Google, as a measure to ensure that sites act according to visitor expectation.