Sodium aluminate is an important commercial inorganic chemical. It works as an effective source of aluminium hydroxide for many industrial and technical applications. Pure sodium aluminate (anhydrous) is a white crystalline solid having a formula variously given as NaAlO₂, NaAl(OH)₄ (hydrated), Na₂O·Al₂O₃, or Na₂Al₂O₄. Commercial sodium aluminate is available as a solution or a solid.
Other related compounds, sometimes called sodium aluminate, prepared by reaction of Na₂O and Al₂O₃ are Na₅AlO₄ which contains discrete AlO₄^5- anions, Na₇Al₃O₈ and Na₁₇Al₅O₁₆ which contain complex polymeric anions, and NaAl₁₁O₁₇, once mistakenly believed to be ß-alumina, a phase of aluminium oxide.