How to Obfuscate Numeric IDs with Hashids in PHP

What is Hashids?

Hashids is a small PHP library that generates YouTube‑like IDs from numbers, useful when you don’t want to expose raw database IDs.

Getting Started

Install the package via Composer: composer require hashids/hashids Import the class and create an instance:

use Hashids\Hashids;

$hashids = new Hashids();

$hashids->encode(1);

Note: Hashids requires the bcmath or gmp extension to work.

Quick Example

use Hashids\Hashids;

$hashids = new Hashids();

$id = $hashids->encode(1, 2, 3); // o2fXhV
$numbers = $hashids->decode($id); // [1, 2, 3]

More Options

Different ways to pass input IDs to encode()

use Hashids\Hashids;

$hashids = new Hashids();

$hashids->encode(1, 2, 3); // o2fXhV
$hashids->encode([1, 2, 3]); // o2fXhV
$hashids->encode('1', '2', '3'); // o2fXhV
$hashids->encode(['1', '2', '3']); // o2fXhV

Make output IDs unique per project

Provide a salt (project name) when constructing the Hashids object:

use Hashids\Hashids;

$hashids = new Hashids('My Project');
$hashids->encode(1, 2, 3); // Z4UrtW

$hashids = new Hashids('My Other Project');
$hashids->encode(1, 2, 3); // gPUasb

Use padding to increase minimum length

Hashids pads the output to at least the specified length.

use Hashids\Hashids;

$hashids = new Hashids(); // no padding
$hashids->encode(1); // jR

$hashids = new Hashids('', 10); // pad to length 10
$hashids->encode(1); // VolejRejNm

Custom alphabet

use Hashids\Hashids;

$hashids = new Hashids('', 0, 'abcdefghijklmnopqrstuvwxyz'); // all lowercase
$hashids->encode(1, 2, 3); // mdfphx

Encode hexadecimal values

Useful for encoding MongoDB ObjectIds.

use Hashids\Hashids;

$hashids = new Hashids();

$id = $hashids->encodeHex('507f1f77bcf86cd799439011'); // y42LW46J9luq3Xq9XMly
$hex = $hashids->decodeHex($id); // 507f1f77bcf86cd799439011

Pitfalls

Decoding always returns an array, even for a single number.

Negative numbers are not supported.

Invalid input to encode() returns an empty string.

Do not use Hashids as a security measure; it is not encryption.

Randomness

Hashids is designed to obscure numeric IDs, not to provide cryptographic security or compression. The algorithm attempts to produce seemingly random, unpredictable IDs, as shown in the examples.

use Hashids\Hashids;

$hashids = new Hashids();
$hashids->encode(5, 5, 5); // A6t1tQ

$hashids->encode(1,2,3,4,5,6,7,8,9,10); // wpfLh9iwsqt0uyCEFjHM
$hashids->encode(1); // jR
$hashids->encode(2); // k5
$hashids->encode(3); // l5
$hashids->encode(4); // mO
$hashids->encode(5); // nR