--- title: I tested 5 AI tools for refactoring CSS: Here’s what I... description: A hands-on comparison tests ChatGPT (GPT-5.5), Claude (Sonnet 5), Copilot (Raptor Mini), Cursor (Composer 2.5 Fast), and Gemini (3.5 Flash) on refactoring a... canonical: https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: I tested 5 AI tools for refactoring CSS: Here’s what I learned | daily.dev og:description: A hands-on comparison tests ChatGPT (GPT-5.5), Claude (Sonnet 5), Copilot (Raptor Mini), Cursor (Composer 2.5 Fast), and Gemini (3.5 Flash) on refactoring a... og:url: https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh og:image: https://api.daily.dev/og/posts/IjfvUsJnh.png og:image:alt: I tested 5 AI tools for refactoring CSS: Here’s what I learned 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. # I tested 5 AI tools for refactoring CSS: Here’s what I learned **[LogRocket](https://daily.dev/sources/logrocket)** · 21 min read · 0 upvotes · 0 comments ## Summary A hands-on comparison tests ChatGPT (GPT-5.5), Claude (Sonnet 5), Copilot (Raptor Mini), Cursor (Composer 2.5 Fast), and Gemini (3.5 Flash) on refactoring a deliberately trap-laden CSS stylesheet with seven specific pitfalls: cascade order with !important, stacking contexts, near-duplicate color values, specificity ties, partial cleanup of redundant-but-necessary code, selector scoping, and vendor-prefixed properties. Every single tool introduced at least one regression, most commonly mishandling the hover box-shadow cascade. Cursor and Copilot, both agentic editor-based tools, outperformed the chat-based assistants, with Cursor finishing first overall (14 points) and Gemini last (7.5 points). Findings show agentic tools that edit files in place tend to preserve more context than chat tools that regenerate entire stylesheets, but all tools still require careful human review of visual regressions and unrequested changes. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Which AI coding assistant is best at refactoring CSS without introducing regressions? Cursor scored highest in a seven-test CSS refactoring benchmark, finishing with 14 out of a possible 17 points, followed by Copilot with 12, ChatGPT and Claude tied at 9.5, and Gemini last at 7.5. Cursor and Copilot, both agentic editor-based tools, outperformed the chat-interface tools (ChatGPT, Claude, Gemini) because they edit files in place rather than regenerating the entire stylesheet. _See how developers weigh AI coding assistant tradeoffs like this on daily.dev before picking one for CSS work._ ### Why did my AI-refactored CSS change the hover box-shadow value on my card component? When a CSS rule has two conflicting box-shadow declarations and the first one carries !important, the !important declaration wins regardless of source order, so it renders even though it appears first. Every tested AI tool (ChatGPT, Claude, Copilot, Cursor, Gemini) incorrectly kept the second, non-important box-shadow value when refactoring, changing a tight 4px/12px shadow into a larger, softer 8px/16px one. _Track cascade and specificity gotchas like this !important conflict by following CSS deep dives on daily.dev._ ### Why does an element with position: relative and z-index disappear when I remove z-index during a CSS cleanup? Removing z-index while leaving position: relative sets the element's z-index to auto, meaning it no longer establishes an isolated stacking order, so paint order falls back to HTML source order instead of the explicit value. In one tested case, Claude's refactor did exactly this to an image container competing with a badge, making the badge's visibility depend entirely on markup order rather than CSS. _Developers debugging stacking context regressions can find explainers like this on daily.dev._ ## Similar posts on daily.dev - [My old job feels distant now](https://daily.dev/posts/my-old-job-feels-distant-now-p6vygtvnp) · Hacker News · 1 upvotes · 0 comments - [I tried Cursor, Claude Code, and Google Antigravity for a month and I have a clear winner for you](https://daily.dev/posts/i-tried-cursor-claude-code-and-google-antigravity-for-a-month-and-i-have-a-clear-winner-for-you-lbo9lwei8) · XDA Developers · 0 upvotes · 0 comments - [AI Coding Tools 2026](https://daily.dev/posts/ai-coding-tools-2026-uywmgypmw) · SitePoint · 0 upvotes · 0 comments - [The debugging wars: Cursor 3 takes aim at Claude Code’s agentic edge](https://daily.dev/posts/the-debugging-wars-cursor-3-takes-aim-at-claude-code-s-agentic-edge-xou7apagw) · The New Stack · 1 upvotes · 0 comments - [Choosing the Right AI Coding Agent: Claude Code vs. GitHub Copilot vs. Gemini Code Assist](https://daily.dev/posts/choosing-the-right-ai-coding-agent-claude-code-vs-github-copilot-vs-gemini-code-assist-z9rs5sif2) · Sergio Lema · 6 upvotes · 4 comments --- Tags: [#github](https://daily.dev/tags/github), [#css](https://daily.dev/tags/css) [View this post on daily.dev](https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh) ```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":"I tested 5 AI tools for refactoring CSS: Here’s what I learned","url":"https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh"},"datePublished":"2026-09-06T12:40:37.185Z","dateModified":"2026-09-14T07:21:21.383Z","description":"A hands-on comparison tests ChatGPT (GPT-5.5), Claude (Sonnet 5), Copilot (Raptor Mini), Cursor (Composer 2.5 Fast), and Gemini (3.5 Flash) on refactoring a...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a7bbaacda5f79cc75a8f4030bca2057b?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a7bbaacda5f79cc75a8f4030bca2057b?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"LogRocket","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":"LogRocket","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/logrocket","url":"https://daily.dev/sources/logrocket"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"github,css","timeRequired":"PT21M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"LogRocket","item":"https://daily.dev/sources/logrocket"},{"@type":"ListItem","position":3,"name":"I tested 5 AI tools for refactoring CSS: Here’s what I learned"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/i-tested-5-ai-tools-for-refactoring-css-here-s-what-i-learned-ijfvusjnh#faq","mainEntity":[{"@type":"Question","name":"Which AI coding assistant is best at refactoring CSS without introducing regressions?","acceptedAnswer":{"@type":"Answer","text":"Cursor scored highest in a seven-test CSS refactoring benchmark, finishing with 14 out of a possible 17 points, followed by Copilot with 12, ChatGPT and Claude tied at 9.5, and Gemini last at 7.5. 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