No. By weight, sea salt and table salt contain about the same amount of sodium—roughly 40%. Sea salt is often marketed as a healthier option, but its main differences from table salt are taste, texture, and processing, not lower sodium.
Some sea salts have larger crystals than finely ground table salt, so a teaspoon of sea salt can hold fewer crystals and therefore slightly less sodium by volume. That does not make sea salt a meaningfully lower-sodium product when you use the same amount by weight. Health guidance focuses on total sodium intake from any salt.
Source: Is sea salt healthier than table salt? — Mayo Clinic Health System