MySQL vs MySQLi: Which PHP Extension Wins for Speed & Security?
MySQL is the classic PHP extension for talking to MySQL databases; MySQLi is its rebuilt sibling adding prepared statements, object-oriented style, and built-in speed boosts.
Legacy code still ships with mysql_* calls, so new devs copy-paste, hit “undefined function” errors, and scramble to Google. Hosting panels list both, making the choice feel like a coin toss instead of a strategic decision.
Key Differences
MySQL extension is procedural only, no native prepared statements, and removed since PHP 7. MySQLi offers dual interfaces (procedural + OOP), parameterized queries, SSL connections, and supports asynchronous queries.
Which One Should You Choose?
If you’re writing new code or upgrading, choose MySQLi. It’s faster on repeated queries via prepared-statement caching and blocks SQL injection by default. Legacy projects locked on PHP 5.2 can stay on MySQL, but migration scripts are trivial.
Is MySQL extension still safe to use?
No; it was deprecated in PHP 5.5 and removed in PHP 7. Running it forces you to stay on outdated, unsupported PHP versions.
Does MySQLi need more server resources?
Minimal overhead; any modern host handles it. The security gains far outweigh the extra few kilobytes of RAM.