Tutorials References Menu

PHP Tutorial

PHP HOME PHP Intro PHP Install PHP Syntax PHP Comments PHP Variables PHP Echo / Print PHP Data Types PHP Strings PHP Numbers PHP Math PHP Constants PHP Operators PHP If...Else...Elseif PHP Switch PHP Loops PHP Functions PHP Arrays PHP Superglobals PHP RegEx

PHP Forms

PHP Form Handling PHP Form Validation PHP Form Required PHP Form URL/E-mail PHP Form Complete

PHP Advanced

PHP Date and Time PHP Include PHP File Handling PHP File Open/Read PHP File Create/Write PHP File Upload PHP Cookies PHP Sessions PHP Filters PHP Filters Advanced PHP Callback Functions PHP JSON PHP Exceptions

PHP OOP

PHP What is OOP PHP Classes/Objects PHP Constructor PHP Destructor PHP Access Modifiers PHP Inheritance PHP Constants PHP Abstract Classes PHP Interfaces PHP Traits PHP Static Methods PHP Static Properties PHP Namespaces PHP Iterables

MySQL Database

MySQL Database MySQL Connect MySQL Create DB MySQL Create Table MySQL Insert Data MySQL Get Last ID MySQL Insert Multiple MySQL Prepared MySQL Select Data MySQL Where MySQL Order By MySQL Delete Data MySQL Update Data MySQL Limit Data

PHP XML

PHP XML Parsers PHP SimpleXML Parser PHP SimpleXML - Get PHP XML Expat PHP XML DOM

PHP - AJAX

AJAX Intro AJAX PHP AJAX Database AJAX XML AJAX Live Search AJAX Poll

PHP Examples

PHP Examples PHP Compiler

PHP Reference

PHP Overview PHP Array PHP Calendar PHP Date PHP Directory PHP Error PHP Exception PHP Filesystem PHP Filter PHP FTP PHP JSON PHP Keywords PHP Libxml PHP Mail PHP Math PHP Misc PHP MySQLi PHP Network PHP Output Control PHP RegEx PHP SimpleXML PHP Stream PHP String PHP Variable Handling PHP XML Parser PHP Zip PHP Timezones

PHP md5() Function

❮ PHP String Reference

Example

Calculate the MD5 hash of the string "Hello":

<?php
$str = "Hello";
echo md5($str);
?>
Try it Yourself »

Definition and Usage

The md5() function calculates the MD5 hash of a string.

The md5() function uses the RSA Data Security, Inc. MD5 Message-Digest Algorithm.

From RFC 1321 - The MD5 Message-Digest Algorithm: "The MD5 message-digest algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. The MD5 algorithm is intended for digital signature applications, where a large file must be "compressed" in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA."

To calculate the MD5 hash of a file, use the md5_file() function.


Syntax

md5(string,raw)

Parameter Values

Parameter Description
string Required. The string to be calculated
raw Optional. Specifies hex or binary output format:
  • TRUE - Raw 16 character binary format
  • FALSE - Default. 32 character hex number


Technical Details

Return Value: Returns the calculated MD5 hash on success, or FALSE on failure
PHP Version: 4+
Changelog: The raw parameter became optional in PHP 5.0

More Examples

Example

Print the result of md5():

<?php
$str = "Hello";
echo "The string: ".$str."<br>";
echo "TRUE - Raw 16 character binary format: ".md5($str, TRUE)."<br>";
echo "FALSE - 32 character hex number: ".md5($str)."<br>";
?>
Try it Yourself »

Example

Print the result of md5() and then test it:

<?php
$str = "Hello";
echo md5($str);

if (md5($str) == "8b1a9953c4611296a827abf8c47804d7")
  {
  echo "<br>Hello world!";
  exit;
  }
?>
Try it Yourself »

❮ PHP String Reference