Never lose Google traffic to a silent deploy again
SilentSEO catches the broken hydration, stale canonicals, and lost structured data your Lighthouse CI misses — before Google notices. See what crawlers actually see on your Next.js, Remix, or Astro site in under a minute.
- Next.js
- Remix
- Astro
- Nuxt
- Gatsby
- Any SPA
Your Lighthouse CI isn’t watching production
You shipped a fix last week. A subtle hydration regression dropped half your indexed pages from Google. You only noticed days later when traffic cratered. SilentSEO would have caught it on the next scheduled scan.
Up to 60%
of content can be invisible to crawlers in client-rendered apps
1 merge
is all it takes to silently wipe your SEO overnight
3-10 days
before you notice the traffic drop in Google Analytics
What SilentSEO catches that others miss
We compare raw HTML (what crawlers see) vs rendered DOM (what users see) on every scan, and alert you the moment they drift apart.
Hydration parity
Content parity score between SSR and post-hydration DOM. Catches JS-only content invisible to Googlebot and most AI crawlers.
Canonical drift
Detects when your canonical URL changes after hydration, or silently breaks between deploys.
Structured data loss
Alerts when JSON-LD structured data disappears from SSR or only loads via JavaScript.
Baseline regression
Every scan is compared to the previous one. You get alerted the moment title, canonical, meta, or score drops.
Framework-aware checks
Next.js App Router vs Pages Router, Remix defer gaps, Astro client:only islands — checks tailored to your stack.
Slack & Discord alerts
Get pinged in your team channel within minutes of a deploy breaking your indexability. Not days later in GA.
How it works
Enter a URL
Paste your production URL. We fetch raw HTML and render it in a real Chromium browser — just like Googlebot.
See what crawlers miss
Rendering diff, hydration parity score, meta audit, framework-specific issues — all compared SSR vs CSR.
Set up monitoring
Schedule daily or weekly scans. Get Slack/Discord alerts the moment something regresses.
SilentSEO vs everything else
Lighthouse tells you your site is bad today. SilentSEO tells you which deploy broke it, what regressed, and how to fix it.
| Capability | SilentSEO | Lighthouse CI | Screaming Frog | Ahrefs / Semrush |
|---|---|---|---|---|
| SSR vs CSR rendering diff | ✓ | — | — | — |
| Hydration parity scoring | ✓ | — | — | — |
| Baseline regression detection | ✓ | — | — | — |
| Framework-aware checks | ✓ | ~ | — | — |
| Slack/Discord alerts | ✓ | — | — | ✓ |
| Continuous monitoring | ✓ | — | manual | ✓ |
| On-deploy scanning | ✓ | ✓ | — | — |
| Price | Free | Free | $259/yr | $29+/mo |
Frequently asked questions about SEO regression monitoring
How is this different from Lighthouse?
Lighthouse audits a single page at a point in time. SilentSEO continuously monitors your production site, compares SSR vs CSR output, detects regressions between deploys, and alerts you in Slack/Discord when something breaks. Lighthouse tells you your score — we tell you when and why it changed.
Do I need Next.js / Remix / Astro?
No. SilentSEO works with any website. But we provide framework-specific checks and code examples for Next.js (App Router & Pages Router), Remix, and Astro. Generic SPA and static sites get full rendering diff and meta audit.
What does 'hydration parity' mean?
It's the percentage of content that matches between your server-rendered HTML (what Google crawls) and your post-JavaScript DOM (what users see). Low parity = crawlers are missing content. It's a leading reason React sites lose search traffic.
Can I use this for sites built with Lovable, Bolt, or v0?
Yes — these tools generate React, Next.js, and similar SPA-style code. SilentSEO scans the deployed site and shows exactly what crawlers see vs what users see. Common issues: client-only meta tags, JS-only content, missing JSON-LD.
How do baseline regressions work?
Your first scan becomes the baseline. Every subsequent scan is compared to it. If your title changes, canonical URL drifts, structured data disappears, or hydration parity drops — we detect it and alert you. You can see the exact before/after diff.
Is my data private?
Yes. Scans are only visible to you (or your team). We never share scan results publicly unless you create a shareable link. All data is stored encrypted at rest.