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PostgreSQL json_strip_nulls() Function

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The PostgreSQL json_strip_nulls() function recursively removes object fields whose JSON value is null. By default, it leaves null elements in arrays unchanged.

This variant accepts and returns json. For the jsonb equivalent, see jsonb_strip_nulls().

json_strip_nulls() Syntax

This is the syntax of the PostgreSQL json_strip_nulls() function:

json_strip_nulls(json_value JSON [, strip_in_arrays BOOLEAN]) -> JSON

Parameters

json_value

Required. The JSON value to process.

strip_in_arrays

Optional in PostgreSQL 18 and later. When true, also removes JSON null elements from arrays; the default is false. In earlier versions, omit this argument.

Return value

The PostgreSQL json_strip_nulls() function recursively removes object fields whose JSON value is null. By default, null array elements remain. In PostgreSQL 18 and later, pass true for strip_in_arrays to remove those array elements too.

If you provide a NULL parameter, the json_strip_nulls() function will return NULL.

json_strip_nulls() Examples

The following example shows how to use the PostgreSQL json_strip_nulls() function to remove a null object field from a given JSON value.

SELECT json_strip_nulls('[1, null, 3, {"x": 1, "y": null}]');

  json_strip_nulls
--------------------
 [1,null,3,{"x":1}]

Here, the function removes the object field y but leaves the array’s null element in place, which is the default behavior.

Remove null array elements (PostgreSQL 18+)

Pass true as the second argument to remove JSON nulls from arrays as well:

SELECT json_strip_nulls('[1, null, 3, {"x": 1, "y": null}]', true);

 json_strip_nulls
------------------
 [1, 3, {"x": 1}]