SEOmonitor's Rank Tracker gives you the option to download a saved copy of the last available SERP, for each device.
How does this work?
We store the HTML page that was the basis for the rank extraction on the corresponding day, and provide it at the click of a button (either on the ranks or in the keyword sidebar).
We have also built a Chrome Extension that complements this feature: the SERP Discrepancy Checker.
Checking the SERP can come in handy when you consider there’s been a crawling error or just want to check the SERP details that are not processed by SEOmonitor (yet).