Generate YouTube-like ids from numbers. Use Hashids when you do not want to expose your database ids to the user.
npm install hashids
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Hashids is small JavaScript library to generate YouTube-like ids from numbers. Use it when you don't want to expose your database ids to the user: http://hashids.org/javascript
Install Hashids via:
``shell`
yarn add hashids
(or just directly use the code at dist/hashids.js)
#### Use in ESM-compatible environments (webpack, modern browsers)
`javascript
import Hashids from 'hashids'
const hashids = new Hashids()
console.log(hashids.encode(1))
`
#### Use in CommonJS environments (most often Node.js)
`javascript
const Hashids = require('hashids/cjs')
const hashids = new Hashids()
console.log(hashids.encode(1))
`
Note: When using Node that supports conditional exports, require('hashids') (version >=13) will also work.
#### Use as global in the browser (wherever ES6 is supported; 5KB)
`html`
#### Use in TypeScript:
import or require, based on the environment (see above). If you want to use the CommonJS module syntax (require), you'll need to install the Node.js types from the DefinitelyTyped repository.
`
npm install @types/node
If you want to use the ESM syntax (import Hashids from 'hashids'), you will need to include the following options in your tsconfig.json.
`json`
{
"allowSyntheticDefaultImports": true,
"esModuleInterop": true
}
The above is not required if you import the CommonJS version directly: import Hashids from 'hashids/cjs'.
If you get errors stating: Cannot find name 'BigInt', add "esnext.bigint" or "esnext" to your tsconfig.json file, under "lib":
`json`
{
"compilerOptions": {
...
"lib": [
"esnext.bigint",
...
]
}
}
Note that your environment doesn't actually have to support BigInt for hashids to function.
`javascript
const hashids = new Hashids()
const id = hashids.encode(1, 2, 3) // o2fXhV
const numbers = hashids.decode(id) // [1, 2, 3]
`
A few more ways to pass to encode():
`javascript
const hashids = new Hashids()
console.log(hashids.encode(1, 2, 3)) // o2fXhV
console.log(hashids.encode([1, 2, 3])) // o2fXhV
// strings containing integers are coerced to numbers:
console.log(hashids.encode('1', '2', '3')) // o2fXhV
console.log(hashids.encode(['1', '2', '3'])) // o2fXhV
// BigInt support:
console.log(hashids.encode([1n, 2n, 3n])) // o2fXhV
// Hex notation BigInt:
console.log(hashids.encode([0x1n, 0x2n, 0x3n])) // o2fXhV
`
Make your ids unique:
Pass a "salt" to make your ids unique (e.g. a project name):
`javascript
var hashids = new Hashids('My Project')
console.log(hashids.encode(1, 2, 3)) // Z4UrtW
var hashids = new Hashids('My Other Project')
console.log(hashids.encode(1, 2, 3)) // gPUasb
`
Use padding to make your ids longer:
Note that ids are only padded to fit at least a certain length. It doesn't mean that your ids will be _exactly_ that length.
`javascript
const hashids = new Hashids() // no padding
console.log(hashids.encode(1)) // jR
const hashids = new Hashids('', 10) // pad to length 10
console.log(hashids.encode(1)) // VolejRejNm
`
Pass a custom alphabet:
`javascript`
const hashids = new Hashids('', 0, 'abcdefghijklmnopqrstuvwxyz') // all lowercase
console.log(hashids.encode(1, 2, 3)) // mdfphx
Default alphabet is abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890.
Since v2.0 you can even use emojis as the alphabet.
Encode hex instead of numbers:
Useful if you want to encode numbers like Mongo's ObjectIds.
Note that there is _no_ limit on how large of a hex number you can pass.
`javascript
var hashids = new Hashids()
var id = hashids.encodeHex('507f1f77bcf86cd799439011') // y42LW46J9luq3Xq9XMly
var hex = hashids.decodeHex(id) // 507f1f77bcf86cd799439011
`
Please note that this is not the equivalent of:
`javascript
const hashids = new Hashids()
const id = Hashids.encode(BigInt('0x507f1f77bcf86cd799439011')) // y8qpJL3ZgzJ8lWk4GEV
const hex = Hashids.decode(id)[0].toString(16) // 507f1f77bcf86cd799439011
`
The difference between the two is that the built-in encodeHex will
always result in the same length, even if it contained leading zeros.
For example hashids.encodeHex('00000000') would encode to qExOgK7 and decode back to '00000000' (length information is preserved).
1. When decoding, output is always an array of numbers (even if you encode only one number):
`javascript
const hashids = new Hashids()
const id = hashids.encode(1)
console.log(hashids.decode(id)) // [1]
`
2. Encoding negative numbers is not supported.
3. If you pass bogus input to encode(), an empty string will be returned:
`javascript
const hashids = new Hashids()
const id = hashids.encode('123a')
console.log(id === '') // true
`
4. Do not use this library as a security tool and do not encode sensitive data. This is not an encryption library.
The primary purpose of Hashids is to obfuscate ids. It's not meant or tested to be used as a security or compression tool. Having said that, this algorithm does try to make these ids random and unpredictable:
No repeating patterns showing there are 3 identical numbers in the id:
`javascript`
const hashids = new Hashids()
console.log(hashids.encode(5, 5, 5)) // A6t1tQ
Same with incremented numbers:
`javascript
const hashids = new Hashids()
console.log(hashids.encode(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)) // wpfLh9iwsqt0uyCEFjHM
console.log(hashids.encode(1)) // jR
console.log(hashids.encode(2)) // k5
console.log(hashids.encode(3)) // l5
console.log(hashids.encode(4)) // mO
console.log(hashids.encode(5)) // nR
`
This code was written with the intent of placing created ids in visible places, like the URL. Therefore, by default the algorithm tries to avoid generating most common English curse words by generating ids that never have the following letters next to each other:
c, f, h, i, s, t, u
You may customize the chars that shouldn't be placed next to each other by providing a 4th argument to the Hashids constructor:
`js`
// first 4 arguments will fallback to defaults (empty salt, no minimum length, default alphabet)
const hashids = new Hashids(undefined, undefined, undefined, 'zyxZYX')
If your environment supports BigInt, you can use the standard API
to encode and decode them the same way as ordinary numbers.
Trying to decode a BigInt`-encoded hashid on an unsupported environment will throw an error.
MIT License. See the LICENSE file.
You can use Hashids in open source projects and commercial products.
Don't break the Internet. Kthxbye.
[travis-url]: https://travis-ci.org/niieani/hashids.js
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[npm-url]: https://www.npmjs.com/package/hashids
[license-url]: https://github.com/niieani/hashids.js/blob/master/LICENSE
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