Astro 4.3

Emanuele Stoppa
Matthew Phillips
Nate Moore
Bjorn Lu

Astro 4.3 is now available! This release includes a new experimental i18n feature to try out, and improvements to working with your build output, component prop types, Markdown images, and more.

Highlights include:

How to upgrade

To take advantage of the latest features, make sure you’re running the latest version of Astro. You can upgrade to Astro 4.3 by running the @astrojs/upgrade command:

npx @astrojs/upgrade

or by running the upgrade command for your package manager:

npm install astro@latest
pnpm upgrade astro --latest
yarn upgrade astro --latest

Experimental: Add domain support for i18n

Astro 4.3 adds an experimental domains i18n configuration. This allows you to specify different domains or subdomains for different supported locales.

For example, you could now use for your English site, for your French site, and for your Spanish site. Enable the experimental flag i18nDomains and map any or all of your locales to domains using in your astro.config.mjs file:

// astro.config.mjs
import {defineConfig} from "astro/config"
export default defineConfig({
site: "",
output: "server", // required, with no prerendered pages
adapter: node({
mode: 'standalone',
i18n: {
defaultLocaLe: 'en',
locales: ['en', 'es', 'pt_BR', 'pt', 'fr'],
domains: {
fr: "",
es: ""
routing: {
prefixDefaultLocale: true,
experimental: {
i18nDomains: true

Note that this feature requires an entirely server-rendered site with no prerendered pages. Currently, the @astrojs/node and @astrojs/vercel adapters are supported with more adapter compatibility to come!

See more in our internationalization documentation for more details and limitations on this experimental routing feature.

More control over your HTML file output

This release adds a new build.format option called preserve to give you more control over the resulting HTML files in your production build.

The current configuration options (file and directory) either build all of your HTML pages as files matching the route name (e.g. /about.html) or build all of your files as index.html within a nested directory structure (e.g. /about/index.html), respectively. It is not possible to create individual index pages (e.g. /about/index.html) when using the file configuration option.

Rather than introduce a breaking change to file, we added the new preserve format which will preserve how the filesystem is structured and make sure that is mirrored over to production:

  • about.astro becomes about.html
  • about/index.astro becomes about/index.html

What you see is what you get! This feature unlocks better compatibility with certain web servers who have strict requirements on how files are structured.

See the build.format configuration options reference for more details.

Add ComponentProps type utility

Astro now includes a new ComponentProps type export from astro/types to get the props type of an Astro component. This is similar to React.ComponentProps or Svelte’s ComponentProps.

This type export allows you to reference the Props accepted by another component, even if that component doesn’t export that Props type directly.

import type { ComponentProps } from 'astro/types';
import Button from "./Button.astro";
type MyButtonProps = ComponentProps<typeof Button>;

Fix using images in Markdown without a relative specifier

Previously, using images in Markdown without using a relative specifier (such as ./ or ../) would cause Astro to throw an error.

Now, you can use the standard ![](img.png) syntax in Markdown files for images colocated in the same folder: no relative specifier required!

There is no need to update your project; your existing images will still continue to work. However, you can safely remove any relative specifiers from these Markdown images as they are no longer necessary… as the Markdown spec intended!

![A cute dog](./dog.jpg)
![A cute dog](dog.jpg)
<!-- This dog lives in the same folder as my article! -->

Thanks to Oliver Speir for contributing this fix!

Bug Fixes

As always, additional bug fixes are included in this release. Check out the release notes to learn more.