{"id":23515,"date":"2026-01-12T10:34:59","date_gmt":"2026-01-12T18:34:59","guid":{"rendered":"https:\/\/engineering.fb.com\/?p=23515"},"modified":"2026-01-12T10:34:59","modified_gmt":"2026-01-12T18:34:59","slug":"css-at-scale-with-stylex","status":"publish","type":"post","link":"https:\/\/engineering.fb.com\/2026\/01\/12\/web\/css-at-scale-with-stylex\/","title":{"rendered":"CSS at Scale With StyleX"},"content":{"rendered":"<div class=\"x1lliihq x13xjzxd x14beivq x14z9mp x1lziwak x14l7nz5 xzboxd6 x6xjc82 x13xao1 x6z2cds xscc34e\">\n<p>Build a large enough website with a large enough codebase, and you\u2019ll eventually find that CSS presents challenges at scale. It\u2019s no different at Meta, which is why we open-sourced StyleX, a solution for CSS at scale. StyleX combines the ergonomics of CSS-in-JS with the performance of static CSS. It allows atomic styling of components while deduplicating definitions to reduce bundle size and exposes a simple API for developers.<\/p>\n<p>StyleX has become the standard at companies like Figma and Snowflake. Here at Meta,<a href=\"https:\/\/engineering.fb.com\/2025\/11\/11\/web\/stylex-a-styling-library-for-css-at-scale\/\" target=\"_blank\" rel=\"noopener\"> it\u2019s the standard styling system<\/a> across Facebook, Instagram, WhatsApp, Messenger, and Threads.<\/p>\n<p>On this episode of the Meta Tech Podcast, meet Melissa, a software engineer at Meta and one of StyleX\u2019s maintainers. \u00a0<a href=\"https:\/\/www.threads.com\/@passy_\" target=\"_blank\" rel=\"noopener\">Pascal Hartig<\/a> talks to her about all things StyleX\u2014its origins, how open source has been a force multiplier for the project, and what it\u2019s like interacting with large companies across the industry as they\u2019ve adopted StyleX.<\/p>\n<\/div>\n<div><\/div>\n<p>Download or listen to the episode below:<\/p>\n<p><iframe loading=\"lazy\" style=\"border: none;\" title=\"Libsyn Player\" src=\"\/\/html5-player.libsyn.com\/embed\/episode\/id\/39659430\/height\/90\/theme\/custom\/thumbnail\/yes\/direction\/forward\/render-playlist\/no\/custom-color\/000000\/\" width=\"100%\" height=\"90\" scrolling=\"no\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>You can also find the episode wherever you get your podcasts, including:<\/p>\n<ul>\n<li><a href=\"https:\/\/open.spotify.com\/episode\/051rjeBqtSMZALoJ02jpTN?ref=engineeringatmeta\" target=\"_blank\" rel=\"noopener\">Spotify<\/a><\/li>\n<li><a href=\"https:\/\/podcasts.apple.com\/gb\/podcast\/css-at-scale-with-stylex\/id1370910331?i=1000744322338\" target=\"_blank\" rel=\"noopener\">Apple Podcasts<\/a><\/li>\n<li><a href=\"https:\/\/pocketcasts.com\/podcast\/meta-tech-podcast\/c4ede3e0-1fbf-0136-c266-7d73a919276a\/css-at-scale-with-stylex\/27b5439a-ab94-45a7-b89c-30f2540d9df5?ref=engineeringatmeta\" target=\"_blank\" rel=\"noopener\">Pocket Casts<\/a><\/li>\n<\/ul>\n<p>The\u00a0<a href=\"https:\/\/insidefacebookmobile.libsyn.com\/\" target=\"_blank\" rel=\"noopener\">Meta Tech Podcast<\/a>\u00a0is a podcast, brought to you by Meta, where we highlight the work Meta\u2019s engineers are doing at every level \u2013 from low-level frameworks to end-user features.<\/p>\n<p>Send us feedback on\u00a0<a href=\"https:\/\/instagram.com\/metatechpod\" target=\"_blank\" rel=\"noopener\">Instagram<\/a>,\u00a0<a href=\"https:\/\/threads.net\/@metatechpod\" target=\"_blank\" rel=\"noopener\">Threads<\/a>, or\u00a0<a href=\"https:\/\/twitter.com\/metatechpod\" target=\"_blank\" rel=\"noopener\">X<\/a>.<\/p>\n<p>And if you\u2019re interested in learning more about career opportunities at Meta visit the\u00a0<a href=\"https:\/\/www.metacareers.com\/?ref=engineering.fb.com\" target=\"_blank\" rel=\"noopener\">Meta Careers<\/a>\u00a0page.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Build a large enough website with a large enough codebase, and you\u2019ll eventually find that CSS presents challenges at scale. It\u2019s no different at Meta, which is why we open-sourced StyleX, a solution for CSS at scale. StyleX combines the ergonomics of CSS-in-JS with the performance of static CSS. It allows atomic styling of components [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/engineering.fb.com\/2026\/01\/12\/web\/css-at-scale-with-stylex\/\">Read More&#8230;<\/a><\/p>\n","protected":false},"author":51,"featured_media":23517,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[191,174,6],"tags":[1923],"class_list":["post-23515","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-culture","category-open-source","category-web","tag-meta-tech-podcast","fb_content_type-article"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v19.3 (Yoast SEO v19.12) - 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