Identicons

While the GitHub-style identicons are well-designed and widely implemented, they're square. And while this is perfectly acceptable in many designs, variety in choice is never a bad thing. This project aims to apply the simplicity of GitHub identicons to other shapes and styles.

I'd love to hear how you use these!

Use

The first thing you need to do is find a way to hash the data you want to "identify" with an identicon. For example, you could use MD5 to produce this transformation: "Hello, world!" => '6cd3556deb0da54bca060b4c39479839'). The hash doesn't need to be enormous, but should be more than 9 bytes. The function doesn't need to be complex, but each bit in the hash should have about a 50/50 chance of being 1 or 0. The less random the hash is, the more predictable the image will be, so just using incremental user ids is probably not enough for variation.

This hash can either be a string of hexadecimal digits or an ArrayBuffer.

An important note: this code is open source (obviously), does no further processing on the provided hashes, and may or may not use the entirety of the hash to generate an image. DO NOT use these identicons to represent sensitive data, even if you use some supposedly secure hashing algorithm. While it may be tempting to use something like the hex representation of a scrambled user email as a hash, please don't. That's equivalent to setting your user's public username to their email. Identicons are not encryption.

Generation

The best way to learn what the options do is to try them out here.

const identicon = require('svg-identicon')
identicon(options)

Not every option is used for every type of identicon.

• options: object
  • hash: string
    • A string of hexadecimal digits used to generate the identicon.
  • type: string
    • The type of identicon to generate ('SQUARE', 'CIRCULAR', or 'POLYGONAL').
  • width: number = 128
    • The dimension of the image in pixels.
  • size: number
    • A sort of dimension describing the complexity of the identicon. For squares identicons, it's the number of boxes on a side. For circular it's the number of shells.
  • segments: number
    • Separates each shell into the provided number of segments.
  • symmetricAxisTilt: number = null
    • Simultaneously forces the identicon to be symmetric across a single axis and sets the angle of this axis in degrees. (NOTE: This is not the same thing as rotating the identicon. It will look different at each angle mod 180). To have no symmetry, set this value to null.
  • background: object
    • color: string = '#EEEEEE'
    • width: number = options.width
    • rx: number = 0

Square

Required Options:

• type = 'SQUARE'
• hash

Other Options:

• size
• width

Circular

Required Options:

• type = 'CIRCULAR'
• hash

Other Options:

• size
• width
• segments
• symmetricAxisAngle

Polygonal

Required Options:

• type = 'POLYGONAL'
• hash

Other Options:

• size
• width
• segments

Output

The return value of identicon is the string representation of an SVG. You can save this to a file, parse it, add it to a DOM, log it, etc...

Node:

const fs = require('fs')

let svg = identicon({ type: 'SQUARE', hash: '1234567890ABCDEF' })

fs.writeFile(./'identicon.svg', svg, console.log)

Browser (after using webpack):

let svg = identicon({ type: 'SQUARE', hash: '1234567890ABCDEF' })

let container = document.getElementById("container");
container.innerHTML = svg;