[!INCLUDE asdb-fabric-se-and-dw]

BASE64_ENCODE converts the value of a varbinary into a base64 encoded varchar.

:::image type="icon" source="../../includes/media/topic-link-icon.svg" border="false"::: Transact-SQL syntax conventions

BASE64_ENCODE (expression [, url_safe])

An expression of type varbinary (n | max)

Optional integer literal or expression, which specifies whether the output of the encode operation should be URL-safe. Any number other than 0 evaluates to true. The default value is 0.

• Varchar(8000)
• Varchar(max) if the input is varbinary(max)
• Varchar(max) if the input is varchar(n) where n > 6000
• If the input expression is null, the output is null.

The encoded string alphabet is that of RFC 4648 Table 1 and may add padding. The URL-safe output uses the base64url alphabet of RFC 4648 Table 2 and doesn't add padding. This function doesn't add any new line characters.

In each case, the database default collation is used. For more information on the supported collations in [!INCLUDE fabric], see Tables.

If url_safe is true, the base64url string that is generated is incompatible with SQL Server's XML and JSON base64 decoders.

In the following example, simple varbinary is base64 encoded.

SELECT Base64_Encode(0xA9) as "Encoded © symbol";

[!INCLUDEssResult_md]

------------  
qQ==
(1 row affected)

In the following example, a string is base64 encoded. The string must first be casted to a varbinary.

SELECT BASE64_ENCODE (CAST ('hello world' as varbinary))

[!INCLUDEssResult_md]

------------  
aGVsbG8gd29ybGQ=
(1 row affected)

In the following example, the first select doesn't specify url_safe, however the second select does specify url_safe.

SELECT BASE64_ENCODE(0xCAFECAFE)

[!INCLUDEssResult_md]

------------  
yv7K/g==
(1 row affected)

The following example specifies that the output is URL-safe.

SELECT BASE64_ENCODE(0xCAFECAFE, 1);

[!INCLUDEssResult_md]

------------  
yv7K_g
(1 row affected)

• BASE64_DECODE (Transact SQL)