Pretext.js

Pretext.js's 概要

Pretext.js is a pure JavaScript and TypeScript-first library for fast text measurement and layout without touching the DOM. It eliminates forced synchronous reflows by using Canvas for one-time glyph measurements via prepare(), followed by instant pure arithmetic layouts with layout(). Achieving ~2ms for 1,000 blocks, it supports 12+ writing systems including CJK, Arabic, Hebrew, Thai, Hindi, and Korean. Zero runtime dependencies, real font metrics, reusable handles for multiple widths. Perfect for virtual scrolling, AI chat bubbles, multilingual feeds, and performance-critical text-heavy UIs. 14k+ GitHub stars.

Pretext.js's 特徴

• Zero DOM reads after prepare()

• Real font metrics via Canvas measureText()

• Multilingual support for 12+ writing systems

• TypeScript-first with full types

• Reusable prepared handles for multiple container widths

• Zero runtime dependencies

• Pure arithmetic layout for instant results

• Accurate line breaking and bidirectional text

Pretext.js's Q&A

Pretext.js's 価格

Free open-source library published on npm with zero runtime dependencies. No paid tiers or subscriptions mentioned.