On a webmaster video hangout yesterday, Google trends analyst John Mueller strongly recommended that people migrating from HTTP to HTTPS do so with 301 redirects on a per-URL basis. He said you should not use other types of redirects, such as 303s or others; you should stick with 301 redirects for these migrations.
Back in August 2014, Google announced the HTTPS ranking boost, and since then, we have published several HTTPs migration plans and site migration tips.
Mueller explained that “if you start using other kinds of HTTPS result codes for redirects, then… we kind of have to reconsider and think ‘well, are they doing something unique here that’s not just a generic site move?’” He said that will then lead Google down the path of reprocessing each and every URL, which will result in making “these moves take a lot longer and make it a lot harder for us to just pass on all of the signals to the new version of the site.”
Here is the transcript from the video:
Below is the video embed. He starts talking about this around 29 minutes into the video:
