Text Identicon
Generate a GitHub-style 5×5 SVG identicon from any string.
Overview
The Text Identicon generator turns any string into a GitHub-style 5x5 pixel-grid SVG avatar. Type a username, email or any seed and the tool emits a mirrored geometric pattern in a hashed colour, perfect for placeholder avatars in comment threads, user lists or anywhere you need a visually distinctive but deterministic icon.
The generator is aimed at frontend developers wiring up user-list mockups, forum operators needing privacy-friendly avatar fallbacks and educators teaching hashing concepts. Long-tail searches like "github-style identicon generator", "deterministic svg avatar from string" and "5x5 identicon hash colour" all resolve here.
How it works
The tool hashes the input string with a fast non-cryptographic hash (FNV-1a / xxHash-style) and uses the digest bytes to drive two decisions: a colour and a 5x5 pixel pattern. The leftmost 3 columns of the 5x5 grid are filled based on individual hash bits — each bit decides whether one cell is on or off — and the rightmost 2 columns are a mirror of the leftmost 2, producing the characteristic vertical symmetry that makes identicons recognisable.
The colour is derived by taking three hash bytes as HSL components and clamping them into a pleasing band (saturation 50-80%, lightness 35-60%) so every identicon has good contrast against a light background. Output is a clean SVG with a fixed viewBox, scalable to any pixel size without rasterisation.
Examples
"ada@example.com" → blue-green mirrored pattern
"grace@example.org" → warm orange pattern, different shape
Same seed → byte-identical SVG every time
500x500 render → crisp because the SVG is vector
FAQ
Are the icons unique?
With 5x5 grids and a colour bucket, the visual space is finite — collisions are possible across millions of users. They are perfect for distinguishing a handful of items but not as a unique identifier.
Why mirrored?
Vertical symmetry makes the pattern feel like a face or shield and aids visual recognition. It is the same trick GitHub's classic identicon used.
Will the colour be accessible against any background?
Saturation and lightness are clamped to produce good contrast against white. Dark-mode users may want to invert the SVG fill in CSS.
Is the hash cryptographic?
No — a fast non-cryptographic hash is enough because the use case is visual differentiation, not security. Different similar strings still produce visibly different identicons.
Can I customise the grid size?
The current build uses 5x5 to match the GitHub style. Larger grids (7x7, 9x9) are an option for future versions.