Indxel — the free Semrush alternative for developers

Indxel wins for CI/CD deploy-time SEO validation, while Semrush wins for marketing-driven keyword research and backlink tracking. If you are a developer shipping Next.js, Nuxt, or Astro apps, you do not need a $1,560/year marketing subscription to catch missing canonical tags. Indxel provides an open-source CLI and npm package that audits your metadata, scores pages 0-100, and fails your GitHub Actions build if your SEO is broken—all for free.

What is Indxel, and how does it handle technical SEO?

Indxel is an open-source SEO infrastructure toolkit for developers that validates metadata, scores pages, and fails CI/CD builds on broken SEO. It operates directly from your terminal as a CLI, npm package, and MCP server.

Think of Indxel as ESLint for SEO. Marketing tools crawl your site days after you deploy to production, find errors, and send an email report to a manager. Indxel runs on localhost:3000 or against your Vercel preview URLs, catching missing og:image tags and malformed JSON-LD before the pull request merges.

You install it via npm, configure your rules, and run it. The CLI outputs warnings and errors in the exact same format developers expect from standard linters—one line per issue, with the file path, rule ID, and a clear description.

$ npx indxel check --ci
 
Auditing http://localhost:3000...
 
/about
  error  [title-length]       Title exceeds 60 characters (72)
  error  [og-image-missing]   Missing OpenGraph image
  warn   [meta-desc-short]    Description under 50 characters (34)
 
/blog/how-to-cache
  error  [canonical-match]    Canonical URL does not match absolute path
  error  [jsonld-invalid]     Missing required 'author' field in Article schema
 
✖ 4 errors, 1 warning
Build failed. Run with --verbose for details.

Indxel enforces 15 strict rules covering title length (50-60 chars), description presence, og:image HTTP status, canonical URL resolution, and JSON-LD validity. You define the baseline score required to pass (e.g., minScore: 90), and if a PR drops your SEO score to 89, the build fails.

What is Semrush, and who actually needs it?

Semrush is a $129.95/mo marketing platform built for SEO professionals to conduct keyword research, track competitor rankings, and analyze backlink profiles across the web.

Semrush is a data aggregator. It maintains a database of 26 billion keywords, tracks historical search engine results page (SERP) positions, and crawls the web to map out domain authorities and backlink toxicity. If you run an agency managing content strategy, or if you have a dedicated SEO marketing team whose primary KPI is organic traffic growth through link building, Semrush is the industry standard.

However, Semrush's Site Audit tool is fundamentally disconnected from the software development lifecycle. It operates as an external crawler. You give it a production URL, it schedules a crawl, and hours later, it generates a PDF or a dashboard of issues.

For developers, this workflow is broken. When Semrush flags a 404 image or a missing meta description, the code has already shipped to production. A developer then has to create a Jira ticket, checkout a new branch, fix the metadata, open a PR, and deploy again. Semrush audits the symptoms in production; it does not guard the source code.

How do Indxel and Semrush compare on features?

Indxel provides native CI/CD integration and code-level metadata validation, whereas Semrush offers massive proprietary databases for keywords and backlinks.

CI/CD Integration and Local Auditing

Indxel wins for deployment safety. You run npx indxel check against a local dev server. It parses the DOM, executes JavaScript to evaluate client-side rendered metadata, and validates tags against your configuration. If you pass --ci, it exits with a non-zero code when errors occur, instantly failing your GitHub Action. Semrush has no CLI, no CI/CD integration, and cannot audit a local environment.

Keyword and Competitor Research

Semrush wins for market research. Indxel provides basic keyword autocomplete data, but Semrush tracks 26 billion keywords, calculates keyword difficulty, maps competitor content gaps, and estimates search volume trends. Indxel does not attempt to compete here. If you need to know exactly what keywords your competitor ranks for in the UK market, you need Semrush.

Programmatic SEO and Indexing

Indxel wins for programmatic control. Indxel includes an SDK that hooks into your application code. You can use defineSEO() to dynamically generate valid JSON-LD schemas. Furthermore, Indxel integrates directly with the IndexNow API and Google Indexing API. When you merge a PR that generates 500 new programmatic pages, Indxel automatically pushes those new URLs to search engines. Semrush only tracks whether pages are indexed after the fact; it does not actively push URLs to Google via API.

How do the pricing models compare?

Indxel's core CLI and SDK are completely free and open-source, while Semrush starts at $129.95 per month with strict limits on daily reports and users.

Semrush operates on a traditional enterprise SaaS model. You pay per seat, and you pay for data limits. Indxel operates on an open-core infrastructure model. The tools developers use to validate code are free forever.

Here is the Total Cost of Ownership (TCO) breakdown for three different team profiles (pricing as of March 2026):

The Solo Developer

If you are a solo developer building a SaaS or a blog, spending $130/month on Semrush just to run a site audit is a waste of capital. You install the Indxel CLI for free, add the check to your package.json scripts, and get 0-100 scoring and metadata validation at zero cost.

The Engineering Team

For a team of 5 developers, Semrush forces you to buy additional seats at $45/month per user if you want everyone to access the dashboards. Indxel's CLI is free for all 5 developers to run locally. If the team wants the Indxel Cloud Dashboard to track historical SEO diffs across deployments, they pay a flat $19/month for the Plus plan.

When should developers choose Indxel?

Choose Indxel if you ship code frequently and want to enforce SEO rules in your CI/CD pipeline before deployments reach production.

You use a modern JavaScript framework. If you build with Next.js, Nuxt, Astro, or SvelteKit, your metadata is highly dynamic. A single typo in your generateMetadata function can strip title tags across 10,000 programmatic pages. Indxel crawls your local build or preview deployment and validates that the JavaScript actually hydrated the correct meta tags.

You require deployment gating. Your team has strict quality controls. You use ESLint for code quality, Prettier for formatting, Playwright for E2E testing, and you need an equivalent for SEO. Adding npx indxel check --ci to your GitHub Actions ensures that a junior developer cannot accidentally merge a PR containing <meta name="robots" content="noindex"> into the main branch.

You generate schema markup dynamically. Writing raw JSON-LD is error-prone. Missing a single required field in a Product schema disqualifies the page from Google's rich snippets. Indxel's SDK provides typed functions to generate schema, and the CLI validates that the output strictly matches schema.org requirements.

When should teams choose Semrush?

Choose Semrush if your primary focus is content strategy, competitor gap analysis, and building backlink profiles for a dedicated marketing team.

You run link-building campaigns. If your strategy relies on finding unlinked brand mentions, analyzing toxic backlinks, or finding guest post opportunities based on domain authority, Semrush is mandatory. Indxel does not index the web's backlink graph.

You need historical ranking data. Semrush tracks exact SERP positions for millions of keywords over years. If you need to prove to a client that their ranking for "best CRM software" moved from position 12 to position 4 over the last six months, Semrush provides the exact charts and reports to demonstrate that ROI.

You manage non-technical content teams. If your workflow involves marketers writing content, researching keyword difficulty, and tracking topic clusters without touching a single line of code, Semrush provides the UI they need. Marketers cannot run a CLI.

How does Indxel work in code?

Indxel runs locally via CLI, integrates into GitHub Actions, and provides TypeScript SDKs for runtime metadata generation.

We do not abstract SEO into a dashboard that developers have to log into. We bring the validation directly to your codebase.

1. The Local CLI Check

You can check any local or remote URL instantly. The --diff flag compares your current local build against your production URL, showing exactly what metadata changed.

npx indxel check http://localhost:3000 --diff https://my-production-site.com
 
Comparing localhost:3000 against my-production-site.com...
 
/pricing
  + Added: JSON-LD Product Schema
  - Removed: <meta name="keywords"> (Deprecated tag removed)
  ~ Changed: Title length increased from 42 to 58 characters
 
Score: 94/100 (+4 from production)

2. CI/CD GitHub Actions Integration

To prevent bad SEO from reaching production, add Indxel to your deployment pipeline. This workflow runs after your Vercel preview deployment finishes, targeting the specific preview URL.

name: SEO Guard
on: [pull_request]
 
jobs:
  seo-validation:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
      
      # Assume a previous step outputs the Vercel preview URL
      - name: Run Indxel SEO Check
        run: npx indxel check ${{ env.PREVIEW_URL }} --ci --min-score 90
        env:
          INDXEL_TOKEN: ${{ secrets.INDXEL_TOKEN }}

If the scan scores below 90, the action fails, returning a non-zero exit code and blocking the merge.

3. Type-Safe Metadata Generation

Instead of manually typing out OpenGraph tags and JSON-LD, use the Indxel npm package to guarantee valid output. The defineSEO function enforces required fields at compile time.

// app/blog/[slug]/page.tsx
import { defineSEO, generateArticleSchema } from 'indxel';
 
export async function generateMetadata({ params }) {
  const post = await fetchPost(params.slug);
  
  // TypeScript will throw an error if 'title' or 'url' is missing
  return defineSEO({
    title: post.title,
    description: post.excerpt,
    url: `https://mysite.com/blog/${post.slug}`,
    image: post.coverImage,
    type: 'article'
  });
}
 
export default function BlogPost({ post }) {
  // Generates strictly validated schema.org JSON-LD
  const schema = generateArticleSchema({
    headline: post.title,
    author: post.author.name,
    datePublished: post.publishedAt,
  });
 
  return (
    <article>
      <script 
        type="application/ld+json" 
        dangerouslySetInnerHTML={{ __html: JSON.stringify(schema) }} 
      />
      <h1>{post.title}</h1>
      <p>{post.content}</p>
    </article>
  );
}

Our verdict on the developer SEO stack

Stop paying for marketing tools to do a developer's job. Use Indxel to guard your deployments, and leave Semrush to the marketing team for keyword research.

Developers need deterministic validation before deployment. Marketers need aggregated data after deployment. These are two different jobs. Indxel completely replaces the technical Site Audit features of Semrush, moves them left into your CI/CD pipeline, and makes them free.

FAQ

What do I get for free with Indxel vs Semrush?

The Indxel CLI, npm package, and MCP server are completely free and open-source (MIT). You get metadata validation, 0-100 scoring, CI/CD gating, JSON-LD generation, and SEO diffs at zero cost. Semrush's free tier is severely restricted, limiting you to 10 searches per day and a capped 100-page crawl limit for site audits.

Can I switch entirely from Semrush to Indxel?

They solve different problems, so it depends on your role. If you only need deploy-time SEO validation and CI/CD gating, Indxel replaces that need entirely for free. If you rely on Semrush for keyword research, analyzing competitor backlinks, and tracking historical SERP positions, keep Semrush for that specific use case and add Indxel to your CI/CD pipeline.

What are the limitations of Indxel's free tier?

The CLI, npm package, and MCP server have no limitations and no paywalls—they are fully open-source. The paid Plus plan ($19/mo) adds the cloud dashboard for historical tracking, the auto-indexation engine (pushing URLs to Google/IndexNow), and team monitoring. No core validation feature is gated behind a paywall in the developer tools.

Does Indxel check for broken links like Semrush does?

Yes, the Indxel CLI crawls your specified entry point and validates all internal links, returning exact file paths and line numbers for any 404s it encounters. Unlike Semrush, which crawls production slowly, Indxel validates these links locally or on your staging environment in seconds, failing the build if a broken link is detected.