Licensing and regulation — the first check, before anything else
Before checking design, bonuses or game selection, check who operates the site and under what license. Serious gambling sites display a license number from a recognized regulator (e.g. Malta's MGA, the UK's UKGC, or other established authorities) at the bottom of the page, and that number can be verified directly on the regulator's own site. A site that hides operator details, shows no license number, or points to a company registered in an unsupervised jurisdiction is an immediate red flag.
Remember: there is no Israeli regulation covering foreign gambling sites. Even a site with a valid foreign license operates outside Israeli law, so any financial dispute falls almost entirely on the player. For a broader legal picture, see is gambling legal in Israel and our general gambling in Israel overview.