[Home](./index.md) > [@firebase/firestore](./firestore.md) > [lite](./firestore_lite.md) > [WhereFilterOp](./firestore_lite.wherefilterop.md) ## WhereFilterOp type Filter conditions in a [where()](./firestore_.where.md) clause are specified using the strings '&lt;', '&lt;=', '==', '!=', '&gt;=', '&gt;', 'array-contains', 'in', 'array-contains-any', and 'not-in'. Signature: ```typescript export declare type WhereFilterOp = '<' | '<=' | '==' | '!=' | '>=' | '>' | 'array-contains' | 'in' | 'array-contains-any' | 'not-in'; ```