---
title: >-
  Automatic CSS subsetting for {% stylesheet %} tags - Shopify developer
  changelog
description: >-
  Shopify’s developer changelog documents all changes to Shopify’s platform.
  Find the latest news and learn about new platform opportunities.
source_url:
  html: 'https://shopify.dev/changelog/automatic-css-subsetting-for-stylesheet-tags'
  md: >-
    https://shopify.dev/changelog/automatic-css-subsetting-for-stylesheet-tags.md
metadata:
  effectiveApiVersion: ''
  affectedApi: []
  primaryTag:
    displayName: Themes
    handle: dev_themes
  secondaryTag:
    displayName: Update
    handle: update
  indicatesActionRequired: true
  createdAt: '2026-04-14T10:29:11-04:00'
  postedAt: '2026-04-23T12:00:00-04:00'
  updatedAt: '2026-04-23T11:42:40-04:00'
  effectiveAt: '2026-04-15T12:00:00-04:00'
---

April 23, 2026

Tags:

* Action Required
* Themes

# Automatic CSS subsetting for `{% stylesheet %}` tags

Shopify is introducing CSS content subsetting for `{% stylesheet %}` tags to improve storefront performance.

Starting April 20, 2026, Shopify only delivers the CSS from `{% stylesheet %}` tags that are relevant to the sections, blocks, and snippets rendered on each page, instead of serving all `{% stylesheet %}` CSS on every page load.

## What this means for your theme

If your theme's CSS classes are self-contained – each file's `{% stylesheet %}` only styles HTML elements within that same file or its direct children (rendered via `{% render %}`) – no changes are needed. Your theme is already compatible.

However, if a file's `{% stylesheet %}` defines CSS classes that are used by HTML elements in other, unrelated files, those styles may not be included on pages where the defining file isn't rendered. This is the pattern to watch for and fix.

Please refer to the [stylesheet subsetting docs](https://shopify.dev/docs/storefronts/themes/best-practices/performance/stylesheet-subsetting) for additional detail and guidance.