Getting started

Install svelte-vitals and run your first health check in seconds.

What is svelte-vitals?

svelte-vitals is a static code-health checker for SvelteKit. It scores your app per route and site-wide, before you deploy, across six categories: SEO, Performance, Correctness, Security, Architecture, and Accessibility.

The CLI works entirely from source. It resolves every route’s effective <head> by walking the layout chain and parsing <svelte:head> blocks, and it reads component bodies for the rules that live there. No running site and no browser are involved. For prerendered pages, the Vite plugin runs the same rules against the HTML your build actually ships. That is the more accurate of the two checks, since nothing is left dynamic.

Prerequisites

Node.js 24.16 or later is required.

Installation

No install needed for a one-off run:

npx svelte-vitals@latest

To add it as a dev dependency:

npm install --save-dev svelte-vitals
# or
pnpm add -D svelte-vitals

First run

Run inside the root of any SvelteKit project:

npx svelte-vitals@latest --verbose

To target a sub-directory:

npx svelte-vitals@latest ./apps/web --verbose

Example output (--verbose shows every passed check individually rather than just a count):

Svelte Vitals  ·  static mode

Health: 79/100
SEO Score: 79/100   (route avg 96 · capped at 79: critical present)

Critical (1)
────────────────────────
✗ seo/title-presence  Missing <title>
            /none
            src/routes/none/+page.svelte

Passed (3)
────────────────────────
✓ seo/title-presence  <title>  /blog
✓ seo/title-presence  <title>  ↯ dynamic  /dynamic
✓ seo/title-presence  <title>  /static

↯ = set dynamically (verified at runtime).

A ↯ marker means the value is set dynamically, as in <title>{data.title}</title>. Dynamic titles pass. svelte-vitals flags only genuinely missing or empty metadata. Without --verbose, the Passed section collapses to a bare count, Passed (3), and this footnote is omitted, since no ↯ marker would then be on screen for it to explain.

Exit codes

Code	Meaning
`0`	No failing findings
`1`	A critical finding is present (or the `--fail-on` / `--min-health` threshold was reached)
`2`	Execution error: not a SvelteKit project, or an internal error

These codes are stable and suitable for CI gates.

Next steps

Not sure which package to reach for? See Choosing a package for a comparison of the CLI, the Vite plugin, the GitHub Action, and Agent Skills.
See CLI reference for all flags.
Use Plugin mode to integrate with vite build.
Install Agent Skills to let AI agents apply the rules and run the analysis themselves. npx skills add oekazuma/svelte-vitals installs them for Claude Code / Codex / Cursor in one step.