A good insulated beach bag has thick foam and a leak-proof liner.

Yes, you can skip the separate cooler—but only if the bag’s insulation is actually decent. Most beach bags with a “cooler compartment” are just a thin layer of mylar over a fabric pouch. That won’t keep anything cold for more than 30 minutes.

Look for bags that specify at least 5–8mm of foam insulation in the cooler section. Check that the liner is waterproof (not just water-resistant) and that the zipper closes tightly. A removable cooler pouch is actually better—easier to clean and you can pull it out to use as a standalone cooler if needed.

Don’t expect miracles. Even with a solid insulated compartment, you’ll want to add a reusable ice pack and pre-chill your snacks. For a few hours on the sand, it’ll do the job. For all-day trips, bring the separate cooler.