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Mubix Labs

Features

Detailed reference for every check and tool in SEO Insight Engine.

SEO Checker

Analyzes HTML files (and JSX/TSX components via a live render) for common SEO issues.

What it checks:

  • <title> tag presence, length (warns if under 10 or over 60 characters)
  • <meta name="description"> presence and length (warns if over 160 characters)
  • <meta name="viewport"> presence (critical for mobile ranking)
  • Heading structure warns if multiple <h1> tags are found on one page
  • Image alt attributes flags every image missing an alt text
  • Canonical link detects missing or duplicate canonical tags
  • robots.txt validates file exists and is correctly formatted
  • sitemap.xml validates file exists

Supported file types: .html, .htm, and live URLs (via Full Audit/Dashboard)

Accessibility Checker

Runs alongside every SEO check automatically.

What it checks:

  • <html lang=""> attribute required for screen readers
  • Empty links <a> tags with no visible text and no aria-label
  • Empty buttons <button> tags with no text and no aria-label
  • Unlabeled form inputs <input> fields without a corresponding <label> or aria-label
  • Missing alt text (also flagged by SEO checker)

Compliance target: WCAG 2.1 Level AA (subset)

Schema Generator

Generates valid JSON-LD structured data to improve your Google rich results eligibility.

Supported schema types:

  • Article for blog posts and editorial content (includes author, date published)
  • Product for e-commerce and product pages (includes price, currency, aggregate rating)
  • Review for review content

How to use:

  1. Open a file and position your cursor where you want the schema inserted
  2. Run SEO: Generate Schema Markup
  3. Answer the prompts
  4. The schema code is inserted directly at your cursor position, ready to use

Dead Code Detector

Analyzes TypeScript and JavaScript files to find imports that are declared but never referenced in the file.

Supports:

  • Default imports: import foo from 'bar'
  • Named imports: import { foo, bar } from 'baz'
  • Namespace imports: import * as foo from 'bar'

How to use: Open the file you want to check (.ts, .tsx, .js, .jsx), then run SEO: Find Unused Imports.

Note: This is a static file-level check. It does not perform project-wide type analysis. For comprehensive dead code elimination across a full codebase, consider using this alongside a dedicated type checker.

Image Optimizer

Compresses images in-place and converts them to the WebP format for better loading performance.

Supported input formats: JPG, JPEG, PNG

Output format: WebP (with configurable quality default: 80%)

How to use: In the Explorer panel, right-click any .jpg, .jpeg, or .png file → select "SEO: Optimize Image". The compressed file is saved alongside the original with an -optimized.webp suffix. The original file is not modified.

Typical results: 60–85% file size reduction depending on the input image.

Full Audit (Live URL) Free

Renders a URL using a headless browser, then runs all SEO and accessibility checks against the fully-rendered HTML. This means it works correctly on any JavaScript framework React, Next.js, Vue, Angular, Svelte, Astro, and more.

How to use:

  1. Start your local development server (npm run dev, ng serve, etc.)
  2. Run SEO: Run Full Audit (Live URL)
  3. Enter your local URL (e.g. http://localhost:3000)
  4. Results appear in the Output panel

Important: Use http:// not https:// for local dev servers, which typically don't have SSL certificates installed.

Performance Audit Pro

Runs a full Lighthouse audit against your development server and returns:

  • Performance score (0–100)
  • Accessibility score (0–100)
  • SEO score (0–100)
  • LCP — Largest Contentful Paint (how fast the main content loads)
  • CLS — Cumulative Layout Shift (how much the page visually shifts during load)

How to use:

  1. Ensure your dev server is running
  2. Run SEO: Run Performance Audit
  3. Enter your local URL
  4. Wait 10–20 seconds for Lighthouse to complete its analysis

Note: Performance audits are best run on a stable machine with no other heavy processes running, as resource availability affects scores.

Visual Dashboard Pro

Combines the Full Audit and Performance Audit into a single visual panel showing:

  • Color-coded score cards (green ≥ 90, amber ≥ 50, red < 50)
  • LCP and CLS metrics
  • Full list of all issues found, with severity indicators

How to use: Run SEO: Open Full Dashboard and enter your dev server URL.

Framework Support

The Live URL audit works by rendering your page in a headless browser and analyzing the actual HTML output not the source code. This means it works the same way regardless of what framework generated the HTML.

Tested frameworks:

  • React (Create React App, Vite)
  • Next.js (Pages Router and App Router)
  • Vue 3 (Vite)
  • Angular
  • Static HTML

In theory, any framework that runs a local dev server is supported. If you encounter an issue with a specific framework, please report it via our support channel.