--- title: Introducing the new Firebase JS SDK | daily.dev description: Firebase released a new beta version of its JavaScript SDK with a modular API that supports tree-shaking, cutting bundle sizes by up to 80% in some cases (72%... canonical: https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Introducing the new Firebase JS SDK | daily.dev og:description: Firebase released a new beta version of its JavaScript SDK with a modular API that supports tree-shaking, cutting bundle sizes by up to 80% in some cases (72%... og:url: https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro og:image: https://api.daily.dev/og/posts/NdJa28Aro.png og:image:alt: Introducing the new Firebase JS SDK 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. # Introducing the new Firebase JS SDK **[Firebase](https://daily.dev/sources/firebase-blog)** · 7 min read · 0 upvotes · 0 comments ## Summary Firebase released a new beta version of its JavaScript SDK with a modular API that supports tree-shaking, cutting bundle sizes by up to 80% in some cases (72% for auth, 84% for the new firebase/firestore/lite package). The change replaces side-effect imports with explicit function imports, which is a breaking change requiring code updates, though a compatibility library lets developers migrate incrementally. Framework integrations like AngularFire, ReactFire, and RxFire are expected to support the new SDK soon. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why is the new Firebase JS SDK considered a breaking change? It replaces side-effect imports like `import firebase/service` with explicit named function imports (e.g. `import { getAuth } from 'firebase/auth'`) so bundlers like webpack and Rollup can tree-shake unused code. This restructuring means existing code written against the old namespace-based API must be rewritten to use the new modular functions, though a compatibility library eases the transition. _Track Firebase SDK migration guidance and other breaking-change writeups on daily.dev before you refactor._ ### How much smaller is the new Firebase modular SDK compared to the old version? Bundle sizes can shrink by up to 80% overall, with firebase/auth up to 72% lighter and the new firebase/firestore/lite package up to 84% lighter than the standard firebase/firestore for apps that only need one-time reads. Savings depend on tree-shaking support in bundlers like webpack and Rollup and which features an app actually uses. _Compare bundle-size tradeoffs across SDKs and tools like this on daily.dev when optimizing web performance._ ### What is firebase/firestore/lite and when should I use it instead of firebase/firestore? firebase/firestore/lite is a lightweight, REST-based subpackage for one-time reads, creates, updates, and deletes without realtime streaming, caching, or offline sync. It can be up to 84% smaller than the full firebase/firestore package, making it suited for fast initial page loads; apps needing realtime data can still switch to or lazy-load the full firestore package. _Developers weighing Firestore Lite versus full Firestore can find comparisons like this on daily.dev._ --- Tags: [#javascript](https://daily.dev/tags/javascript), [#firebase](https://daily.dev/tags/firebase), [#webpack](https://daily.dev/tags/webpack), [#firestore](https://daily.dev/tags/firestore) [View this post on daily.dev](https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro) ```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":"Introducing the new Firebase JS SDK","url":"https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro"},"datePublished":"2026-08-23T12:20:22.574Z","dateModified":"2026-08-23T12:40:24.421Z","description":"Firebase released a new beta version of its JavaScript SDK with a modular API that supports tree-shaking, cutting bundle sizes by up to 80% in some cases (72%...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed721de96163685d26ab7e314be3ebc?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed721de96163685d26ab7e314be3ebc?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Firebase","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":"Firebase","logo":"https://media.daily.dev/image/upload/s--i395oqZH--/f_auto,q_auto/v1787487448/logos/firebase-blog?_a=BAMAMicg0","url":"https://daily.dev/sources/firebase-blog"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"javascript,firebase,webpack,firestore","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Firebase","item":"https://daily.dev/sources/firebase-blog"},{"@type":"ListItem","position":3,"name":"Introducing the new Firebase JS SDK"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/introducing-the-new-firebase-js-sdk-ndja28aro#faq","mainEntity":[{"@type":"Question","name":"Why is the new Firebase JS SDK considered a breaking change?","acceptedAnswer":{"@type":"Answer","text":"It replaces side-effect imports like `import firebase/service` with explicit named function imports (e.g. `import { getAuth } from 'firebase/auth'`) so bundlers like webpack and Rollup can tree-shake unused code. 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