What is stronger grizzly or polar bear?

The difference would be slight, but if we look at the two species, the brown bear has more powerful shoulder muscles, while polar bears have a longer body. Both species can top 1200 pounds or more, and are very powerful. But brown bears seem to be the stronger of the two.
The polar bear is stronger because it is the largest species of bear in the world, however, it is not more aggressive than the grizzly bear. Male polar bears can weigh up to 1000 lbs (half a ton) and stand up to 10 feet tall (on their hind legs). A big grizzly male can weigh up to around 800 lbs.