Compatibility with the JavaScript implementation

The JavaScript implementation produces different hashes in versions 0.1.x and 0.3.x. For compatibility with the older 0.1.x version install hashids 0.8.4 from pip, otherwise the newest hashids.

Basic Usage

Encrypt a single integer:

hashid = hashids.encrypt(123) # 'Mj3'

Decrypt a hash:

ints = hashids.decrypt('xoz') # (456,)

To encrypt several integers, pass them all at once:

hashid = hashids.encrypt(123, 456, 789) # 'El3fkRIo3'

Decryption is done the same way:

ints = hashids.decrypt('1B8UvJfXm') # (517, 729, 185)

Using A Custom Salt

Hashids supports salting hashes by accepting a salt value. If you don’t want others to decrypt your hashes, provide a unique string to the constructor.

hashids = Hashids(salt='this is my salt 1')
hashid = hashids.encrypt(123) # 'nVB'

The generated hash changes whenever the salt is changed:

hashids = Hashids(salt='this is my salt 2')
hashid = hashids.encrypt(123) # 'ojK'

A salt string between 6 and 32 characters provides decent randomization.

Controlling Hash Length

By default, hashes are going to be the shortest possible. One reason you might want to increase the hash length is to obfuscate how large the integer behind the hash is.

This is done by passing the minimum hash length to the constructor. Hashes are padded with extra characters to make them seem longer.

hashids = Hashids(min_length=16)
hashid = Hashids.encrypt(1) # '4q2VolejRejNmGQB'

Using A Custom Alphabet

It’s possible to set a custom alphabet for your hashes. The default alphabet is 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'.

To have only lowercase letters in your hashes, pass in the following custom alphabet:

hashids = Hashids(alphabet='abcdefghijklmnopqrstuvwxyz')
hashid = hashids.encrypt(123456789) # 'kekmyzyk'

A custom alphabet must contain at least 16 characters.

Repeating numbers

There are no repeating patterns that might show that there are 4 identical numbers in the hash:

hashids = Hashids("this is my salt")
hashids.encrypt(5, 5, 5, 5) # '1Wc8cwcE'

The same is valid for incremented numbers:

hashids.encrypt(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) # 'kRHnurhptKcjIDTWC3sx'

hashids.encrypt(1) # 'NV'
hashids.encrypt(2) # '6m'
hashids.encrypt(3) # 'yD'
hashids.encrypt(4) # '2l'
hashids.encrypt(5) # 'rD'