--- title: The quiet problem with unnecessary async | daily.dev description: Marking JavaScript functions as async when they return synchronous data is a subtle but costly pattern. It changes the function's contract, forcing all callers... canonical: https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: The quiet problem with unnecessary async | daily.dev og:description: Marking JavaScript functions as async when they return synchronous data is a subtle but costly pattern. It changes the function's contract, forcing all callers... og:url: https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom og:image: https://api.daily.dev/og/posts/6FhremtOM.png og:image:alt: The quiet problem with unnecessary async 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. # The quiet problem with unnecessary async **[Matt Smith](https://daily.dev/sources/allthingssmitty)** · 4 min read · 49 upvotes · 9 comments ## Summary Marking JavaScript functions as async when they return synchronous data is a subtle but costly pattern. It changes the function's contract, forcing all callers to become async-aware, spreading Promise-based complexity through tests and composition utilities. The real cost is cognitive: async signatures imply I/O or background work, so unnecessary async obscures where real asynchronous boundaries live. The recommendation is to keep synchronous functions synchronous and introduce async semantics only when actual asynchronous work exists. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@andradei** · 2 upvotes > Async as we know today was a mistake. Specially at scale. > > Even in Rust where the thing is strongly typed and follows its strict rules, it's a nightmare to use, implement, maintain, read, write... **@mamadaghaei** · 2 upvotes > > Because `async` doesn’t just change a function implementation. **It changes the shape of the code around it.** > > > **great topic!** **@bestcodes** · 1 upvotes > The "quiet" problem?? 🙄 **@husseinkizz** · 1 upvotes > doesn't top await solve this problem? **@lucas39** · 0 upvotes > Are we talking about a real problem here? I mean, has anyone ever seen an **async** function in a codebase that doesn't contain an **await**? That's never happened to me on any of the projects I've worked on. ## Similar posts on daily.dev - [The Async Mistake That Makes JavaScript Code Lie to You](https://daily.dev/posts/the-async-mistake-that-makes-javascript-code-lie-to-you-b9d5ujlbf) · Medium · 4 upvotes · 0 comments - [What Async Promised and What it Delivered — Causality](https://daily.dev/posts/what-async-promised-and-what-it-delivered-causality-ocp1tkuw6) · Hacker News · 17 upvotes · 6 comments --- Tags: [#javascript](https://daily.dev/tags/javascript), [#react](https://daily.dev/tags/react) [View this post on daily.dev](https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom) ```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":"The quiet problem with unnecessary async","url":"https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom"},"datePublished":"2026-06-08T10:57:08.264Z","dateModified":"2026-06-08T14:19:48.969Z","description":"Marking JavaScript functions as async when they return synchronous data is a subtle but costly pattern. It changes the function's contract, forcing all callers...","image":"https://media.daily.dev/image/upload/s--qPvKM23u--/f_auto/v1722860399/public/Placeholder%2009","thumbnailUrl":"https://media.daily.dev/image/upload/s--qPvKM23u--/f_auto/v1722860399/public/Placeholder%2009","isAccessibleForFree":true,"articleSection":"Matt Smith","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":"Matt Smith","logo":"https://media.daily.dev/image/upload/s--M72x5P5U--/f_auto/v1748760304/logos/allthingssmitty","url":"https://daily.dev/sources/allthingssmitty"},"commentCount":9,"discussionUrl":"https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":49},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":9}],"keywords":"javascript,react","timeRequired":"PT4M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Matt Smith","item":"https://daily.dev/sources/allthingssmitty"},{"@type":"ListItem","position":3,"name":"The quiet problem with unnecessary async"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/the-quiet-problem-with-unnecessary-async-6fhremtom","comment":[{"@type":"Comment","text":"Async as we know today was a mistake. Specially at scale.\nEven in Rust where the thing is strongly typed and follows its strict rules, it’s a nightmare to use, implement, maintain, read, write…","datePublished":"2026-06-08T21:29:03.931Z","url":"https://daily.dev/posts/6FhremtOM#c-o7AXv7XXS","author":{"@type":"Person","name":"Isaac de Andrade","url":"https://daily.dev/andradei","image":"https://avatars.githubusercontent.com/u/2653546?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":2}},{"@type":"Comment","text":"Because async doesn’t just change a function implementation. It changes the shape of the code around it.\n\ngreat topic!","datePublished":"2026-06-11T08:59:09.477Z","dateModified":"2026-06-11T08:59:17.149Z","url":"https://daily.dev/posts/6FhremtOM#c-mjcWyicEN","author":{"@type":"Person","name":"Mohammad Aghaei","url":"https://daily.dev/mamadaghaei","image":"https://avatars.githubusercontent.com/u/65438728?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":2}},{"@type":"Comment","text":"The “quiet” problem?? 🙄","datePublished":"2026-06-14T20:57:46.506Z","url":"https://daily.dev/posts/6FhremtOM#c-g4n4uUF0z","author":{"@type":"Person","name":"Best Codes","url":"https://daily.dev/bestcodes","image":"https://avatars.githubusercontent.com/u/106822363?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1}},{"@type":"Comment","text":"doesn’t top await solve this problem?","datePublished":"2026-06-09T03:20:25.317Z","url":"https://daily.dev/posts/6FhremtOM#c-wBQ0q6BSK","author":{"@type":"Person","name":"Hussein Kizz","url":"https://daily.dev/husseinkizz","image":"https://media.daily.dev/image/upload/s--bqCp79lk--/f_auto/v1704865561/avatars/avatar_WgJOIEdxX"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1}},{"@type":"Comment","text":"Are we talking about a real problem here? I mean, has anyone ever seen an async function in a codebase that doesn’t contain an await? That’s never happened to me on any of the projects I’ve worked on.","datePublished":"2026-06-17T07:05:23.248Z","url":"https://daily.dev/posts/6FhremtOM#c-Yo6t1s6Vv","author":{"@type":"Person","name":"Lucas","url":"https://daily.dev/lucas39","image":"https://lh3.googleusercontent.com/a/ACg8ocIIUWuKYGCrhLQ9bRh_zl_uNxcdY4Gvvwc91aTGmSre6nyWEA=s96-c"}}]} ```