PHP String Case Conversion – Complete Function Guide
Published 2026-01-26 · convertcase.in
PHP has a rich set of built-in functions for string case manipulation. Here is a complete reference with examples.
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1PHP Case Functions
strtolower("HELLO") → "hello"
strtoupper("hello") → "HELLO"
ucwords("hello world") → "Hello World"
ucfirst("hello world") → "Hello world"
lcfirst("HELLO") → "hELLO"2Multibyte (mb_) Functions
For non-ASCII/UTF-8 strings, use mb_strtolower() and mb_strtoupper() to handle characters correctly.
Frequently Asked Questions
Does PHP have a sentence case function?
ucfirst() is the closest — capitalises the first character. For proper sentence case across multiple sentences, you need custom logic.