---
title: performance/preload-missing-as · Preload missing as
description: Every should declare an as attribute.
---
**Severity:** warning
## What it checks
Every `` must have an `as` attribute naming the resource type (`style`, `script`, `font`, `image`, …). A preload without `as` is flagged.
## Why it matters
A `` without an `as` attribute is ignored by the browser (or fetched a second time), wasting the preload.
## How to fix
Add an `as` attribute matching the resource type:
```html
```
## Mode differences
**Source analysis** (the CLI, the dashboard's static baseline) composes each route's `` from `` in the page and its layout chain, followed into repo-local components, plus the known meta components (`svelte-meta-tags`, `svelte-seo`) and any you declare in `metaComponents`. It judges only a **literal** value; it never examines a dynamic one. **Rendered analysis** (the Vite plugin's build pass, a route you visit in the dashboard) reads the shipped ``, where every value is literal; the build pass covers prerendered routes only. When the two disagree, trust the rendered result.
## Disabling
Record existing findings in the suppressions file (`npx svelte-vitals --update-suppressions`), scope the rule per route or path with `overrides`, or turn it off:
```js svelte-vitals.config.js
export default {
rules: {
'performance/preload-missing-as': 'off'
}
};
```