How to Generate a Unique ID in PHP

09/06/2021

Contents

In this article, you will learn how to generate a unique ID in PHP.

PHP uniqid() Function

You can generate a unique ID in PHP using the uniqid() function, which generates a unique ID based on the current time in microseconds.

Here is an example:

<?php
  $uniqueID = uniqid();
  echo $uniqueID;
?>

You can also add a prefix to the unique ID for better readability:

<?php
  $prefix = "Order_";
  $uniqueID = uniqid($prefix);
  echo $uniqueID;
?>

Another option is to use the random_bytes() function to generate a random string of bytes, which can then be converted to a unique ID using bin2hex():

<?php
  $bytes = random_bytes(16);
  $uniqueID = bin2hex($bytes);
  echo $uniqueID;
?>

the uniqid() function generates a unique ID based on the current time in microseconds. It returns a string that is guaranteed to be unique across all systems, as long as it’s called fast enough (i.e., the time between two calls is greater than one microsecond). The function has an optional prefix parameter, which allows you to add a custom string to the beginning of the generated ID.

the random_bytes() function generates a random string of bytes, which can be used as a unique ID. The length of the generated string is determined by the argument passed to the function, in this case 16 bytes. The resulting string of bytes is then converted to a hexadecimal string using the bin2hex() function, making it more human-readable. The random_bytes() function generates cryptographically secure random numbers, which makes it suitable for generating unique IDs.

It’s worth noting that both uniqid() and random_bytes() functions have their limitations and potential drawbacks, so it’s important to choose the right method depending on your use case and requirements.