Identicon and Robohash

This post is a dump [for archival purpose] of exchange between Colin Davis, creator of Robohash, and I that took place in context of a Hacker News about Robohash.


Identicons are a great idea, I really love them.. They’re a good solution to a gut-check “Something is wrong here..”

Sort of like a SSH-fingerprint.

The problem I’ve had with them is that they’re generate not all that memorable. Was that triangles pointing left, then up, or up then left?

This is my attempt at addressing that problem for my own new project, but I’d love to see what you build! If you want to use these images, feel free. They’re CC-BY, so they’re open to the world now 😉


Re ‘not all that memorable’, that’s because identicons were originally designed for ‘distinguishing’ and ‘matching’ data, not ‘memorizing’.

Abstract geometric identicons like my original implementation as well as variations used at WordPress and StackOverflow are, while nearly impossible to remember, distinguishable in a pile which comes in handy when distinguishing the ‘voice’ of individuals in a long thread of comments.

To use identicons as permanent identity, one has to ‘identify’ with their identicon. We can identify faces of our friends because we shared memories with them, stories if you will.

So robotic identicons like yours can be made more memorable if users had some ways to create a story they can associate with it like ‘blue viking with left arm missing’, etc.


That makes a lot of sense. I wasn’t trying to be disparing. It’s a great idea, and very helpful, I just felt like it could go in a slightly different direction for this specific use-case (Public Keys).


I think an interesting way to apply identicon to certs is to map each cert attributes to an ‘attribute’ of identicon, visualizing attributes.

What is Identicon?

Word identify has two meaning:

  1. Establish or indicate who or what (someone or something) is.
  2. Recognize or distinguish.

I chose the name Identicon with second meaning in mind to convey that Identicons’ intended applications are in helping users recognize or distinguish textual information units in context of many.

Textual Data Problem

Human eyes have evolved to recognize individual objects out of a group by noticing visual differences. Unfortunately, textual data are visually similar.

While many different typographic features and techniques have been invented since writing was invented, most of them are for free-form text. Additionally, list and table text layout lack the irregular features free-form text have, like line ends and paragraphs, to use as landmarks.

Icon Solution

Icons do add the necessary visual differences to textual data. Only problem is that icons are typically designed by hand or, in case of avatars, photos or pictures have to uploaded.

Identicon = Generated Icon?

One might say Identicons are simply generated icons. The first implementation of Identicon used salted hash of IP address to generate 9-block colored icon for each blog commenter. Most popular use of Identicon today remains generated iconic avatars.

I think it’s a bit more. Certainly, generated part is required. But the icon part is unnecessarily restrictive unless colored circle or box can be called an icon.

Identicon and QR Code

I was recently asked to provide some information on identicons, a good excuse to restart blogging.

This post, more like notes actually, compares Identicon to QR code which may seem similar visually but are not.

WARNING: I think in random fragments, brief moments of coherency, so my posts will be the same.

Machine vs People


  • QR codes are containers of information.
  • Identicons are shadows of information they are associated with. 


  • QR codes are used to transfer information from real life (RL) objects to computers using only optical means.
  • Identicons are used to distinguish individuals or groups of information.
More to come later. Sorry.