This salt can form multiple hydrates, such as the monohydrate, dihydrate, and the pentahydrate, all of which are white or colorless solids.

Thiosulfate salts are produced by the reaction of sulfite ion with elemental sulfur, and by incomplete oxidation of sulfides.

[2] Thiosulfates are stable in neutral or alkaline solutions, but not in acidic solutions, due to disproportionation to sulfur dioxide and sulfur:[3] Due to this property, it can sequester metals, especially iron.

In the era of silver-based photography, thiosulfate was consumed on a large scale as a "stop" reagent.

This application exploits thiosulfate's ability to dissolve silver halides.