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What’s new in Svelte: September 2025

Deno support, await in consts and open telemetry support

Dani Sandoval

In case you missed it, the main Svelte blog covered how to use SvelteKit’s new OpenTelemetry traces to reliably set up observability instrumentation using instrumentation.server.ts. This month’s round up covers that release and a few other features that rolled out before and after it.

Plenty in the showcase, as well, so let’s dive in!

What’s new in Svelte and Svelte CLI (sv)

  • await is now allowed inside @const declarations (svelte@5.38.0, Docs, #16542)
  • The sv add command has been updated to remove the --no-preconditions and add --no-git-check. With this new flag, even if some files are dirty, no prompt will be shown (sv@0.9.0, Docs, #650)

What’s new in SvelteKit and its adapters

  • Deno is now supported as a supported package manager (sveltejs/adapter-auto@6.1.0, #14163)
  • A new instrumentation.server.ts adds tracing and observability setup (sveltejs/adapter-node@5.3.0, Docs, #13899)
  • The --preserve-output flag prevents deletion of the output directory before packaging (sveltejs/package@2.5.0, Docs, #13055)

For a full list of bug fixes in Svelte, SvelteKit and its adapters, check out their CHANGELOGs here and here.

Community Showcase

Apps & Sites built with Svelte

  • Pollinate provides accurate forecasts designed for allergy sufferers who want to plan their day, or vacation, around pollen levels (Check out the Reddit post on how it was built)
  • Ferndesk is a help center that is kept up to date automatically (the creator shared their demo on the Svelte Reddit)
  • Wplace lets you paint whatever you want on a map of the world
  • Domain Watcher is a domain availability monitor and expiration tracker built with SvelteKit & Cloudflare Workers
  • Motley is a local-first bookmarking/moodboard app
  • TallyHo is a simple time tracking for freelancers
  • MenuScan lets you take a picture of any restuarant menu and get access to the calorie and macro counts for each item
  • Vibe Check provides quick, honest diagnostics for AI‑built apps
  • Joyful is a simple way to write, design, and send beautiful newsletters
  • Eagle Cite lets you highlight, organize, and search your citations in one place
  • Volkara is a set of ADHD-Friendly Productivity Tools
  • Simple Man Archive is an ASCII art archive where anyone can contribute by creating unique ASCII art
  • Thirty is an open-source AI calendar built on familiar foundations
  • Timezones quickly shows and converts timezones across many locations

Learning Resources

Featuring Svelte Contributors and Ambassadors

This Week in Svelte

  • Ep. 112 — Storybook for Svelte Part 1
  • Ep. 113 — Storybook for Svelte Part 2 - Docs
  • Ep. 114 — Changelog Review

To Read

To Watch

Libraries, Tools & Components

  • EXE is a build tool to distribute your full-stack web app as a single executable binary with zero runtime dependencies
  • Svelte Sortable List is a comprehensive package for creating accessible, sortable lists in Svelte applications
  • Markdown UI turns static docs into interactive experiences - instantly
  • Tark UI provides beautiful UI components built with Ark UI and Tailwind
  • Uniface Element is a comprehensive enterprise-grade UI component library built with Svelte 5, designed for modern web applications
  • microfolio is a modern static portfolio generator featuring a file-based content management system using folders and Markdown files
  • Keycloakify is a tool for creating custom Keycloak themes, enabling you to modify the appearance and behavior of Keycloak’s user interfaces
  • PDJsonEditor is a powerful JSON visualization and editing tool with both a code editor and interactive graph views
  • Show & Svelte lets you create fully interactive presentations with Svelte
  • wuchale is a compile-time internationalization (i18n) toolkit that requires zero code changes
  • svelte-overflow-fade is a Svelte action and attachment for adding beautiful fade effects to overflowing content
  • formshape is a type-safe form validation for SvelteKit Remote Functions using Standard Schema compatible validators
  • vite-plugin-svelte-inline-component lets you write tiny Svelte components straight inside your JavaScript / TypeScript tests using tagged‑template literals.
  • vite-plugin-sveltekit-decorators is a Vite plugin that automatically decorates SvelteKit functions with customizable wrappers for logging, analytics, error handling, and more
  • jetbrains-svelte-templates is a compact collection of Live Templates for JetBrains IDEs (like WebStorm and IntelliJ IDEA Ultimate) designed to speed up your Svelte & SvelteKit development

That’s it for this month! Let us know if we missed anything on Reddit or Discord.

Until next time 👋🏼!