Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/) that was published on June 30, 2025. 

# IS\_VALID\_JSON function
<a name="IS_VALID_JSON"></a>

**Note**  
CAN\_JSON\_PARSE and its associated functions parse JSON values as SUPER, which Amazon Redshift parses more efficiently than VARCHAR.  
 Instead of using IS\_VALID\_JSON, we recommend that you validate your JSON strings using the [CAN\_JSON\_PARSE function](CAN_JSON_PARSE.md). 

The IS\_VALID\_JSON function validates a JSON string. The function returns Boolean `true` if the string is properly formed JSON or `false` if the string is malformed. To validate a JSON array, use [IS\_VALID\_JSON\_ARRAY function](IS_VALID_JSON_ARRAY.md)

For more information, see [JSON functions](json-functions.md). 

## Syntax
<a name="IS_VALID_JSON-synopsis"></a>

```
IS_VALID_JSON('json_string')
```

## Arguments
<a name="IS_VALID_JSON-arguments"></a>

 *json\_string*  
A string or expression that evaluates to a JSON string.

## Return type
<a name="IS_VALID_JSON-return"></a>

`BOOLEAN`

## Examples
<a name="IS_VALID_JSON-examples"></a>

To create a table and insert JSON strings for testing, use the following example.

```
CREATE TABLE test_json(id int IDENTITY(0,1), json_strings VARCHAR);

-- Insert valid JSON strings --
INSERT INTO test_json(json_strings) VALUES
('{"a":2}'), 
('{"a":{"b":{"c":1}}}'), 
('{"a": [1,2,"b"]}');

-- Insert invalid JSON strings --
INSERT INTO test_json(json_strings) VALUES
('{{}}'), 
('{1:"a"}'), 
('[1,2,3]');
```

To validate the strings in the preceding example, use the following example.

```
SELECT id, json_strings, IS_VALID_JSON(json_strings) 
FROM test_json
ORDER BY id;

+----+---------------------+---------------+
| id |    json_strings     | is_valid_json |
+----+---------------------+---------------+
|  0 | {"a":2}             | true          |
|  4 | {"a":{"b":{"c":1}}} | true          |
|  8 | {"a": [1,2,"b"]}    | true          |
| 12 | {{}}                | false         |
| 16 | {1:"a"}             | false         |
| 20 | [1,2,3]             | false         |
+----+---------------------+---------------+
```