--- title: This Month in Ladybird | daily.dev description: A monthly recap of progress on the Ladybird browser engine covers 261 merged PRs from 53 contributors, new sponsors, and official IRS tax-exempt status for the... canonical: https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: This Month in Ladybird | daily.dev og:description: A monthly recap of progress on the Ladybird browser engine covers 261 merged PRs from 53 contributors, new sponsors, and official IRS tax-exempt status for the... og:url: https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo og:image: https://api.daily.dev/og/posts/5HZVxKTQO.png og:image:alt: This Month in Ladybird 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. # This Month in Ladybird **[Ladybird Browser](https://daily.dev/sources/ladybird)** · 7 min read · 0 upvotes · 0 comments ## Summary A monthly recap of progress on the Ladybird browser engine covers 261 merged PRs from 53 contributors, new sponsors, and official IRS tax-exempt status for the Ladybird Browser Initiative (retroactive to March 2024). Technical highlights include a more tolerant JavaScript date parser, full Clipboard API support, completed Transferable Streams implementation, initial SharedWorker support, replacement of the in-house BigInt implementation with LibTomMath (fixing a Google Maps performance bottleneck), CSS var()/attr() handling in shorthands, early @page support for print styling, and JS engine optimizations (polymorphic inline caches, faster bound function calls, faster built-in iteration) that together yielded a 10% Speedometer 2.1 speed-up. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What did Ladybird replace its BigInt implementation with, and why? Ladybird replaced its in-house UnsignedBigInteger and SignedBigInteger implementations in LibCrypto with LibTomMath. The change improves both correctness and performance, since BigInt operations showed up prominently in performance profiles when running Google Maps before the switch. _Track engine-level dependency swaps like this on daily.dev before they affect apps relying on browser crypto internals._ ### How did Ladybird improve JavaScript inline cache performance for polymorphic property access? Ladybird expanded its inline caches from monomorphic to polymorphic, allowing each cache to remember up to 4 different object shapes per property access. This raised the cache hit rate on the Speedometer benchmark from 88% to 97%, since real-world code frequently accesses the same property across objects with different shapes. _Engineers optimizing JS engine internals follow benchmarks like this via daily.dev to compare inline caching strategies._ ### How much faster did Ladybird's Web Platform Tests run after its recent optimization? Ladybird cut its Web Platform Tests runtime from over 5 hours to under 1 hour by splitting the test list into multiple chunks and distributing them across multiple runner processes. During the same period it added 15,961 new passing tests, bringing its total to 1,815,223. _Contributors benchmarking browser engine progress can follow WPT milestones like this on daily.dev._ --- Tags: [#javascript](https://daily.dev/tags/javascript), [#open-source](https://daily.dev/tags/open-source) [View this post on daily.dev](https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo) ```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":"This Month in Ladybird","url":"https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo"},"datePublished":"2026-08-31T05:54:39.416Z","dateModified":"2026-08-31T05:56:08.849Z","description":"A monthly recap of progress on the Ladybird browser engine covers 261 merged PRs from 53 contributors, new sponsors, and official IRS tax-exempt status for the...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/f0d04d597be9efdaf11883698ad30378?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/f0d04d597be9efdaf11883698ad30378?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Ladybird Browser","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":"Ladybird Browser","logo":"https://media.daily.dev/image/upload/s--gBOjamNh--/f_auto,q_auto/v1788155675/logos/ladybird?_a=BAMAMicg0","url":"https://daily.dev/sources/ladybird"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"javascript,open-source","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Ladybird Browser","item":"https://daily.dev/sources/ladybird"},{"@type":"ListItem","position":3,"name":"This Month in Ladybird"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/this-month-in-ladybird-5hzvxktqo#faq","mainEntity":[{"@type":"Question","name":"What did Ladybird replace its BigInt implementation with, and why?","acceptedAnswer":{"@type":"Answer","text":"Ladybird replaced its in-house UnsignedBigInteger and SignedBigInteger implementations in LibCrypto with LibTomMath. 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