--- title: Pretext fixed the web | daily.dev description: Pretext, a TypeScript library by former React Core team member Cheng Lou, solves a 30-year-old browser performance problem around text measurement. Instead of... canonical: https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Pretext fixed the web | daily.dev og:description: Pretext, a TypeScript library by former React Core team member Cheng Lou, solves a 30-year-old browser performance problem around text measurement. Instead of... og:url: https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g og:image: https://api.daily.dev/og/posts/nO5Wiqj5g.png og:image:alt: Pretext fixed the web og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Pretext fixed the web **[Bytes by ui.dev](https://daily.dev/sources/bytesdev)** · 5 min read · 1 upvotes · 0 comments ## Summary Pretext, a TypeScript library by former React Core team member Cheng Lou, solves a 30-year-old browser performance problem around text measurement. Instead of triggering expensive DOM layout reflows, it uses the Canvas API to measure text segments and pure arithmetic to compute line breaks and heights. The result is a ~500x speedup: 1,000 items go from ~94ms with dropped frames to ~0.05ms. The newsletter also covers Cloudflare's EmDash (serverless WordPress successor built on Astro), TanStack Router's new signal graph, Inertia.js 3.0, Vue Lynx pre-alpha, and several other web dev releases and tools. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Pretext.js Bypasses DOM Layout Reflow, Enabling Advanced UX Patterns at 120 FPS](https://daily.dev/posts/pretext-js-bypasses-dom-layout-reflow-enabling-advanced-ux-patterns-at-120-fps-b1lmzt2mp) · InfoQ · 13 upvotes · 0 comments --- Tags: [#webdev](https://daily.dev/tags/webdev), [#typescript](https://daily.dev/tags/typescript) [View this post on daily.dev](https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Pretext fixed the web","url":"https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g"},"datePublished":"2026-04-03T21:18:16.491Z","dateModified":"2026-04-03T21:19:05.986Z","description":"Pretext, a TypeScript library by former React Core team member Cheng Lou, solves a 30-year-old browser performance problem around text measurement. Instead of...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7bb73e016087626b55b16a35ed195d6b?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7bb73e016087626b55b16a35ed195d6b?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Bytes by ui.dev","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Bytes by ui.dev","logo":"https://media.daily.dev/image/upload/s--wMrI6PMo--/f_auto/v1718347131/logos/bytesdev","url":"https://daily.dev/sources/bytesdev"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/pretext-fixed-the-web-no5wiqj5g","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"webdev,typescript","timeRequired":"PT5M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Bytes by ui.dev","item":"https://daily.dev/sources/bytesdev"},{"@type":"ListItem","position":3,"name":"Pretext fixed the web"}]} ```