Letter Favicon SVG Avatar Generator

Letter favicon in SVG: a tiny brand mark for any project

A letter favicon is a single-letter SVG monogram that lives in the browser tab — a quick, designer-free brand mark that fills the same slot as the rounded coloured square Notion, Linear and Vercel show in their tabs. Unlike an emoji favicon (limited to the OS emoji set) or a raster ICO (fixed pixel grid, fuzzy on Retina), a letter SVG is vector, scalable, theme-aware, and weighs around 200 bytes. The canonical shape is a coloured square plus a centred <text> node tuned for the 16×16 favicon canvas:

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
  <rect width="100" height="100" rx="20" fill="#3b82f6"/>
  <text x="50" y="72" font-size="64"
    font-family="system-ui, sans-serif"
    text-anchor="middle" fill="white">A</text>
</svg>

Why one letter beats two at favicon sizes

A favicon renders at 16×16, 32×32, sometimes 48×48. Two letters at 16px give you ~7 pixels per glyph — illegible mush, especially on Windows ClearType. A single letter at 16px owns ~10 pixels and reads clean. That is why every modern PWA you see in your tab (Notion, Linear, Figma, Vercel) ships a one-letter mark. Pad the letter 15–20% from the edge so Safari's rounded-corner mask on iOS doesn't clip the glyph, and pick a sans-serif: system-ui works, but Inter, IBM Plex Sans and Public Sans render crisper at tiny sizes thanks to their open apertures.

Shipping the favicon — file or data URI

Two delivery strategies, both browser-supported since Chrome 80, Firefox 41, Safari 9:

• File — save as favicon.svg and reference: <link rel="icon" type="image/svg+xml" href="/favicon.svg">. Cacheable, easy to swap.
• Inline data URI — <link rel="icon" href="data:image/svg+xml,<svg ...>">. Zero extra request — handy for landing pages where every byte counts.
• Apple Touch Icon fallback — iOS Safari ignores SVG favicons for the home-screen icon. Generate a 180×180 PNG of the same letter avatar and add <link rel="apple-touch-icon">.
• ICO fallback — for IE/legacy, keep a 32×32 ICO as /favicon.ico.

Branding, contrast and dark-mode tricks

Pick a background that matches your brand primary and lock white (or black) text against it. WCAG 4.5:1 contrast is the floor; a Stripe-purple #635bff on white text gives ~6.1:1 — safe. Random hashed colours look great for user avatars but kill brand recall on a favicon: use a fixed brand colour here. SVG also lets you adapt to dark mode without a second file — embed a tiny <style>: @media (prefers-color-scheme: dark) { rect { fill: #fff } text { fill: #000 } }. Browsers honour the media query inside SVG.

When to reach for a letter favicon

Use cases: hackathon project that needs to look polished in screenshots; PWA without budget for a logo; personal blog; side project landing page; internal tool tab that needs to be distinguishable in a forest of open tabs. Match the colour to your in-app avatars and OG image and you ship a tiny but coherent brand system. Tools in this space: favicon.io (letter generator + ICO export), ui-avatars.com (PNG), realfavicongenerator.net (multi-format pipeline). All three settle on the same primitive: coloured square + one big letter.

FAQ

One letter or two initials? One. At 16×16 two letters are unreadable. Pick the first letter of the brand or the user's first name and call it done.

Random colour or brand colour? Brand colour. A favicon's job is recall — random hashes break that. Save the hash trick for user avatars, not the tab icon.

Do I still need an ICO file? Only if you support legacy IE/Edge. Modern browsers (Chrome 80+, Firefox 41+, Safari 9+) prefer SVG. A 32×32 ICO as a fallback covers 99% of edge cases.

Should my PWA manifest use the same colour? Yes. Match theme_color and background_color in manifest.json to the favicon background so the splash screen, address bar and tab icon agree.