Identicon Generator

About this tool

The Identicon Generator creates unique, deterministic avatar images from any input text — usernames, email addresses, UUIDs, or arbitrary strings. The input is hashed with SHA-256 in your browser; the first 15 bytes decide which cells of a mirrored 5×5 grid are filled, and the first three bytes set the HSL colour and a dark background tint. The same input always generates the same identicon, and the preview updates as you type. Identicons are widely used as default profile images where no photo has been set; GitHub uses a similar idea for default avatars, though this tool's output will not match GitHub's. Choose a size of 80, 100, 150, 200 or 300 pixels and download the result as a square PNG. The Rounded corners and Circle options change only the on-screen preview. Beside the image you can read the foreground colour, background colour and the first 8 bytes of the SHA-256 hash.

Why use it

• Deterministic — the same input always produces the same identicon, so users see a consistent avatar across sessions.

• SHA-256 hashing ensures even similar inputs (alice, alice2) produce visually distinct icons.

• Downloadable PNG in five sizes from 80 to 300 px.

• No external service: hashing and drawing happen entirely in your browser.

How to use

1. Enter any text — a username, email address, UUID, or arbitrary string — in the Text / seed field.
2. The identicon updates in real time as you type; each change produces a new hash and grid.
3. Pick a size from the Size dropdown: 80, 100, 150, 200 or 300 px.
4. Optionally tick Rounded corners or Circle to change how the preview is displayed.
5. Click Download PNG to save the square identicon as identicon.png.

When it helps

• Generating default profile avatars for user accounts in web apps where users haven't uploaded a photo.
• Creating unique visual identifiers for entities (organizations, repos, machines) in a data dashboard.
• Generating identicons for test user profiles in development.
• Creating visual hash representations of strings or UUIDs.

Examples

Tips

• For email-based identicons, lowercase and trim the email before typing it; the tool hashes exactly what you enter, so Alice@x.com and alice@x.com differ.
• Pick the 300 px size for high-DPI screens and let the browser scale it down.
• When showing many identicons in a list, display them at 32-64px so the 5×5 pattern stays readable without visual noise.
• Cache generated identicons by input hash — recomputing SHA-256 on every render wastes CPU on large user lists.
• Don't rely on identicons as a security cue — different inputs can rarely produce visually similar icons by chance.
• Need a round avatar? Download the square PNG and apply border-radius: 50% where you display it.

Frequently Asked Questions

Glossary

Identicon

A small, hash-based image used as a default avatar. Coined by Don Park in 2007. The output is deterministic from the input, making it a visual fingerprint.

SHA-256

A 256-bit cryptographic hash function from the SHA-2 family. Given any input, it produces a fixed-length 32-byte digest. It is deterministic, fast in JavaScript via SubtleCrypto, and collision-resistant.

Deterministic generation

A property where the same input always produces the same output. Identicons rely on this so a user's avatar is stable across visits without needing server-side storage.

Color seed

The portion of the input hash used to derive the avatar's primary color. Typically the first or last few bits of the hash are mapped into HSL hue, saturation, and lightness.

HSL

Hue-Saturation-Lightness — a cylindrical color model where hue is an angle (0-360°), and saturation and lightness are percentages. Friendlier for procedural color generation than RGB.

Symmetric grid

A pattern where the right half mirrors the left half (and sometimes the bottom mirrors the top). Symmetry makes hash-derived patterns more visually pleasing as avatars.

SVG vs PNG

SVG is a vector format that scales infinitely without aliasing. PNG is a raster format with fixed pixel dimensions. SVG is ideal for identicons because the underlying 5×5 grid renders crisply at any scale.

Data URL

A URL scheme (data:image/png;base64,...) that embeds a file's contents directly into the URL. Useful for inlining identicons into HTML without separate HTTP requests.