Tegaki tackles a problem that many frontend developers face when animating handwriting: how to generate realistic stroke-by-stroke animations from fonts without manually authoring complex paths or relying on native code. Under the hood, it parses font glyph outlines directly in the browser and animates pen strokes with variable timing to simulate natural handwriting.
architecture and core functionality of tegaki
Tegaki is a TypeScript library designed to create handwriting animations from any font by parsing its glyph data client-side. The key architectural choice is to keep the core engine framework-agnostic and lightweight, focusing solely on parsing font outlines and generating stroke paths with timing information.
The core engine operates by extracting stroke-based paths from font glyph outlines, then animating these paths stroke-by-stroke with variable speeds that simulate the natural movement of a pen. This means it doesn’t just draw the glyph statically; it animates the drawing process with timing curves that feel organic.
To integrate with various UI frameworks, Tegaki uses thin adapter layers for React, Svelte, Vue, SolidJS, Astro, and even Web Components. These adapters consume the core engine’s output and handle rendering using the idiomatic patterns of each framework, ensuring the core remains reusable and not tied to any particular UI stack.
Tegaki bundles four handwriting fonts by default, but you can also generate custom font bundles with an interactive generator tool. This extends the library’s flexibility to any font you want to animate in a handwriting style.
Overall, the stack is modern TypeScript targeting web environments, with no native dependencies or server-side processing required. This makes it suitable for client-heavy apps, static sites, or any frontend where you want to add handwriting animations without additional build complexity.
why tegaki’s font parsing and animation approach stands out
What distinguishes Tegaki is its client-side font parsing pipeline that converts vector font glyph outlines into animatable stroke paths without manual path authoring or native code. Most handwriting animation approaches require you to craft SVG paths by hand or preprocess fonts with native tooling.
Tegaki avoids these steps by parsing TrueType or OpenType glyph data directly in the browser at runtime. This is non-trivial because font glyphs are defined as Bézier curves with fill rules, not as explicit stroke sequences. The library reconstructs stroke orders and directions to mimic how a pen would draw the character.
The engine’s timing model adds another layer of realism by varying the speed of each stroke segment, preventing uniform, mechanical drawing animations. This variable timing is a subtle but important detail that improves the natural feel.
Architecturally, the separation of the core animation engine from framework adapters is a clean design choice. It means you can use the same core logic in React, Vue, or vanilla web components without duplication or forced dependencies.
However, the tradeoff here is that the animation quality depends heavily on the font data and the heuristics Tegaki uses to infer stroke order. Complex or non-handwriting fonts might not animate as convincingly. Also, client-side parsing can add some runtime overhead, especially on lower-end devices, though the library is optimized to keep this minimal.
The TypeScript codebase is surprisingly clean and modular, making it approachable for developers who want to understand or extend the engine. The bundled fonts and generator tool also improve developer experience by lowering the barrier to start animating custom fonts.
quick start with tegaki
Getting started with Tegaki is straightforward, especially if you’re using React. Here’s the exact quick start sequence from the official docs:
npm install tegaki
Then a simple React usage example:
import { TegakiRenderer } from 'tegaki';
import caveat from 'tegaki/fonts/caveat';
function App() {
return (
<TegakiRenderer font={caveat} style={{ fontSize: '48px' }}>
Hello World
</TegakiRenderer>
);
}
That’s it. The text draws itself stroke by stroke with natural timing, no additional config needed.
The adapters for other frameworks follow a similar pattern, just swapping out the rendering component. This makes Tegaki a plug-and-play solution for animating text in any modern frontend environment.
verdict: who should consider using tegaki
Tegaki is a solid choice if you want to bring handwriting animation to your web project without the hassle of manually crafting SVG stroke paths or relying on native font processing tools.
Its strengths lie in the client-side parsing pipeline and framework-agnostic engine, which together deliver a lightweight, flexible solution. The built-in fonts and generator tool improve the developer experience.
That said, if your project demands extremely high fidelity handwriting animations or you need to animate extremely complex scripts, Tegaki’s heuristic approach might fall short. The runtime parsing also adds some client overhead, so it’s best suited for applications where animation quality and developer DX outweigh that cost.
Overall, Tegaki fills a niche for frontend developers who want natural handwriting animations from fonts with minimal setup and no native dependencies. The code quality and architecture show thoughtful engineering, making it worth exploring if this fits your use case.
→ GitHub Repo: KurtGokhan/tegaki ⭐ 2,342 · TypeScript