Free real-time odds sites help with line shopping, but compare the same market...

https://100percentsurewins.com/top-5-free-real-time-odds-sites-to-check-before-you-bet/

Free real-time odds sites help with line shopping, but compare the same market at each book. Match spread to spread or total to total, then verify odds, pick, and stake on your bet slip before placing it. Lines move, so check again right before you submit