Astro 2.5 Release

Astro's 2.5 release rolls out with many new features.

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Update: Version 2.5 is old news, check out Astro 3.0!

Astro, the innovative static site builder, has recently released version 2.5, bringing a range of exciting updates and enhancements to its already impressive features. This blog post serves as a comprehensive summary of the key highlights and improvements in Astro version 2.5. From enhanced performance optimizations to new features and improved developer experience, Astro continues to solidify its position as a leading choice for building fast and efficient static websites. So let’s take a look at what’s new in Astro version 2.5!

Table of Contents

Data Collections

Content Collections were introduced in 2.0, now in version 2.5 Astro has added Data Collections. Data Collections live alongside content in the src/content directory. These will typically be JSON or YAML files.

What makes Data Collections different that just importing a data file on your own? Data Collections, like Content Collections, can be validated to match a specified schema which provides type safety when using the data in your pages.

Data Collections are differentiated from Content Collections by passing type: "data" to the defineCollection() function.

Data and Content Collections can now reference one another via the new reference() function. For example, this can be useful for tasks like linking an author to a blog post.

Example Data Collection config:

import { defineCollection, z } from "astro:content";

const authors = defineCollection({
  type: "data",
  schema: z.object({
    name: z.string(),
    avatar: z.string().url(),

export const collections = { authors };

For further details, read the Astro guide on Content Collections.

Static-by-default Hybrid Rendering

In Astro 2.0, they released Hybrid Rendering. The new static pre-rendering by default option flips normal Hybrid Rendering on its head by pre-rendering all but a select few pages. This differs from Hybrid Rendering’s default which only pre-renders a select few pages.

To enable this new (experimental) option, you will need to add the following to your Astro config file:

export default defineConfig({
  output: 'hybrid',
  experimental: {
    hybridOutput: true,

Then, to disable pre-rendering a page, add export const prerender = false; to the front matter of any .astro file.

This can be very useful for sites that have mostly static content with a few pages that change frequently.

HTML Minification

Looking to reduce the size of your site’s files? Then turn on the new HTML minification by adding compressHTML: true to your Astro config file.

Now you don’t need to rely on external tools or extra build steps to accomplish minifications.

Parallelized Rendering

Speed up your build times with the new Parallelized Rendering in your .astro files. Previously each component would be rendered in order, waiting while a particularly blocking component held up the rest of the page. Now Astro will render each component in parallel, greatly improving rendering time.

Other Changes

Astro 2.5 also has support for experimental custom client directives and a new polymorphic type helper. Head over to the Astro blog for more details.

Further Reading