VARCHAR vs CHAR in MySQL: Key Differences and Usage

In MySQL, CHAR is a fixed-length string type that always uses the same amount of storage, while VARCHAR is a variable-length string type that uses only as much storage as needed plus one or two bytes for length. CHAR is faster for fixed-size data, and VARCHAR is more space-efficient for variable-size data.

Quick Comparison

Here is a quick side-by-side comparison of CHAR and VARCHAR in MySQL.

Factor	CHAR	VARCHAR
Storage Size	Fixed length, always uses declared size	Variable length, uses actual string length + 1 or 2 bytes
Maximum Length	0 to 255 characters	0 to 65,535 bytes (depending on row size and character set)
Padding	Right-padded with spaces to fixed length	No padding, stores exact string length
Performance	Faster for fixed-length data due to fixed storage	Slightly slower due to variable length handling
Use Case	Best for fixed-size data like codes or IDs	Best for variable-size data like names or emails

Key Differences

CHAR stores strings with a fixed length. If the string is shorter than the declared size, MySQL pads it with spaces on the right to fill the length. This makes CHAR fast for fixed-size data because the storage size is predictable.

VARCHAR stores strings with variable length. It uses only the space needed for the string plus one or two extra bytes to record the length. This saves space when string lengths vary a lot but adds a small overhead for length management.

Another difference is the maximum size: CHAR can hold up to 255 characters, while VARCHAR can hold much longer strings, limited by the row size and character set. Also, CHAR pads with spaces, which can affect comparisons, while VARCHAR stores strings exactly as given.

CHAR Example

mysql

CREATE TABLE example_char (
  code CHAR(5)
);

INSERT INTO example_char (code) VALUES ('abc');

SELECT code, LENGTH(code) AS length, OCTET_LENGTH(code) AS byte_length FROM example_char;

Output

code | length | byte_length
-----|--------|------------
abc  | 5      | 5

VARCHAR Equivalent

mysql

CREATE TABLE example_varchar (
  code VARCHAR(5)
);

INSERT INTO example_varchar (code) VALUES ('abc');

SELECT code, LENGTH(code) AS length, OCTET_LENGTH(code) AS byte_length FROM example_varchar;

Output

code | length | byte_length
-----|--------|------------
abc  | 3      | 3

When to Use Which

Choose CHAR when you know the data will always be the same length, like fixed codes, country abbreviations, or status flags. This gives you faster access and simpler storage.

Choose VARCHAR when the data length varies, such as names, emails, or descriptions. It saves space and handles different lengths efficiently.

In general, prefer VARCHAR for most text data unless you have a clear reason to use fixed-length CHAR.

Key Takeaways

CHAR uses fixed storage and pads strings with spaces.

VARCHAR uses variable storage and stores exact string length.

CHAR is faster for fixed-length data; VARCHAR is more space-efficient for variable-length data.

Use CHAR for fixed-size codes and VARCHAR for variable-size text.

Maximum length for CHAR is 255, while VARCHAR can be much longer.