Not (at this time) obtaining scores or reports from MyFICO, I can't speak to that particular question, so I'll address Credit Karma. They use the Vantage 3.0 scoring model, which, as you've seen, is different - sometimes dramatically different - from the FICO 8 model. More than a few people appear to regard VS 3.0 as being next to trash at best, hence the nickname "FAKO" that you'll sometimes come across. The fact is, they're not fake scores - they're real ones, and accurate as far as their own scoring model is concerned, and they're going to be revamped extensively soon. The issue is that VS 3.0 is not widely used except in the apartment rental/leasing field, or to provide "educational" scores for credit consumers; most lenders prefer to use FICO 8.
Don't completely discount the Vantage scores, but realize that, at least at the present time, they're not terribly useful as an actual guide to figuring your odds of getting new or additional credit. I have to admit, though, that I wish more lenders did use Vantage, because as you can see from my sig, my VS 3.0 scores are consistently higher than my FICO scores - in fact my Vantage TU score went up five points just today because a new car loan was added to my TU report. One further note: Several lenders, such as Penfed, will use scoring models that are different from either Vantage or FICO 8. Penfed prefers to use FICO NextGen 2 (which, by the way, gives me an EQ score just one point lower than my Vantage score).
