--- title: Tinder cuts app cold starts by 47% with new R8... description: Tinder's Android team used the new R8 Configuration Analyzer to identify and fix overly broad keep rules that were blocking code optimization. An in-house... canonical: https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Tinder cuts app cold starts by 47% with new R8 Configuration Analyzer | daily.dev og:description: Tinder's Android team used the new R8 Configuration Analyzer to identify and fix overly broad keep rules that were blocking code optimization. An in-house... og:url: https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8 og:image: https://api.daily.dev/og/posts/GQlbaZjn8.png og:image:alt: Tinder cuts app cold starts by 47% with new R8 Configuration Analyzer 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. # Tinder cuts app cold starts by 47% with new R8 Configuration Analyzer **[Android Developers Blog](https://daily.dev/sources/androiddev)** · 5 min read · 1 upvotes · 0 comments ## Summary Tinder's Android team used the new R8 Configuration Analyzer to identify and fix overly broad keep rules that were blocking code optimization. An in-house library's unscoped keep rule was preventing R8 from optimizing large parts of the app. After refining it, Tinder cut cold starts by 47%, reduced APK size by 28.98% (to 61.5 MB), lowered user-perceived ANRs by 28%, and raised their R8 optimization score from 28% to 50%. The team also added CI/CD monitoring to prevent future regressions and published an R8 Analyzer skill for use with agentic tools. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the R8 Configuration Analyzer and what does it show? It is an Android tool that reports shrinking, optimization, and obfuscation scores for an app's R8 configuration, highlighting broad, redundant, or obsolete keep rules, including ones introduced by external libraries. It also identifies the classes affected by each keep rule so developers can refine rules and unlock more code optimization without risking runtime crashes. _Developers auditing R8 keep rules can track tooling changes like this on daily.dev._ ### How did Tinder reduce Android app cold start time by 47%? Tinder used the R8 Configuration Analyzer to find that an in-house library had added an overly broad keep rule (-keep public class * { public protected *; }) that blocked optimization across many unrelated classes. Removing that rule raised their R8 optimization score from 28% to 50%, cutting cold starts by 47%, shrinking APK size by 28.98% to 61.5 MB, and reducing ANRs by 28%. _Teams chasing app startup wins can follow real optimization case studies like this on daily.dev._ ### How can I use the R8 Configuration Analyzer with agentic development tools? Google published an R8 Analyzer skill file on GitHub that agentic tools can use to summarize the R8 Configuration Analyzer report automatically, surfacing optimization, obfuscation, and shrinking scores plus the five most impactful keep rules blocking code optimization, without requiring a developer to manually parse the HTML report. _daily.dev helps developers keep up with new agentic tooling integrations like this one._ ## Similar posts on daily.dev - [How Reddit used the R8 optimizer for high impact performance improvements](https://daily.dev/posts/how-reddit-used-the-r8-optimizer-for-high-impact-performance-improvements-06qzize75) · Android Developers Blog · 0 upvotes · 0 comments - [Enabling R8 optimization at scale with AI-assisted debugging](https://daily.dev/posts/enabling-r8-optimization-at-scale-with-ai-assisted-debugging-kovtjstfc) · Grab Tech Blog · 0 upvotes · 0 comments - [Android Developers Blog: Configure and troubleshoot R8 Keep Rules](https://daily.dev/posts/android-developers-blog-configure-and-troubleshoot-r8-keep-rules-93owf7hzc) · Android Developers Blog · 1 upvotes · 0 comments --- Tags: [#android](https://daily.dev/tags/android) [View this post on daily.dev](https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8) ```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":"Tinder cuts app cold starts by 47% with new R8 Configuration Analyzer","url":"https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8"},"datePublished":"2026-08-18T18:01:32.904Z","dateModified":"2026-09-14T07:55:04.932Z","description":"Tinder's Android team used the new R8 Configuration Analyzer to identify and fix overly broad keep rules that were blocking code optimization. An in-house...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/adf4913b75da698e8f10d7f3767bf280?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/adf4913b75da698e8f10d7f3767bf280?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Android Developers Blog","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":"Android Developers Blog","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/a3d55bb1d63c48e7bd91b833eb5c2c3c","url":"https://daily.dev/sources/androiddev"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"android","timeRequired":"PT5M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Android Developers Blog","item":"https://daily.dev/sources/androiddev"},{"@type":"ListItem","position":3,"name":"Tinder cuts app cold starts by 47% with new R8 Configuration Analyzer"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/tinder-cuts-app-cold-starts-by-47-with-new-r8-configuration-analyzer-gqlbazjn8#faq","mainEntity":[{"@type":"Question","name":"What is the R8 Configuration Analyzer and what does it show?","acceptedAnswer":{"@type":"Answer","text":"It is an Android tool that reports shrinking, optimization, and obfuscation scores for an app's R8 configuration, highlighting broad, redundant, or obsolete keep rules, including ones introduced by external libraries. It also identifies the classes affected by each keep rule so developers can refine rules and unlock more code optimization without risking runtime crashes. Developers auditing R8 keep rules can track tooling changes like this on daily.dev."}},{"@type":"Question","name":"How did Tinder reduce Android app cold start time by 47%?","acceptedAnswer":{"@type":"Answer","text":"Tinder used the R8 Configuration Analyzer to find that an in-house library had added an overly broad keep rule (-keep public class * { public protected *; }) that blocked optimization across many unrelated classes. Removing that rule raised their R8 optimization score from 28% to 50%, cutting cold starts by 47%, shrinking APK size by 28.98% to 61.5 MB, and reducing ANRs by 28%. Teams chasing app startup wins can follow real optimization case studies like this on daily.dev."}},{"@type":"Question","name":"How can I use the R8 Configuration Analyzer with agentic development tools?","acceptedAnswer":{"@type":"Answer","text":"Google published an R8 Analyzer skill file on GitHub that agentic tools can use to summarize the R8 Configuration Analyzer report automatically, surfacing optimization, obfuscation, and shrinking scores plus the five most impactful keep rules blocking code optimization, without requiring a developer to manually parse the HTML report. daily.dev helps developers keep up with new agentic tooling integrations like this one."}}]} ```