The 2025 Technical SEO Audit
Why This Audit Comes First
Exceptional content underperforms if pages are slow to paint, unstable while loading, or unresponsive to input—issues that degrade trust and suppress rankings.
This audit converts Core Web Vitals into a repeatable, engineering‑friendly checklist that protects user experience and unlocks durable growth across topic clusters.
Core Web Vitals: Targets & Measurement
2025 thresholds at the 75th percentile
LCP ≤ 2.5s measures main content load speed, INP ≤ 200ms quantifies responsiveness across the session, and CLS < 0.1 captures visual stability.
Field vs. lab alignment
Use CrUX/RUM for field truth and synthetic tests for diagnosis; track “Good pages” share weekly and guard against regressions after each deployment.
Image & Font Strategy
For LCP and CLS
Serve WebP/AVIF with srcset/sizes, explicit width/height to reserve space, and preconnect+preload the hero image with matching imagesrcset/imagesizes.
Fonts
Preload critical font files, scope usage, and apply font-display to minimize FOIT/FOUT without blocking first render.
JavaScript & INP
Main‑thread budget
Break long tasks, defer non‑critical scripts, code‑split heavy routes, and offload work to Web Workers to improve interaction latency.
Event work optimization
Reduce synchronous handlers, batch DOM updates, and avoid layout thrashing to lower worst‑case interaction delays.
Render‑Blocking & Critical Path
Critical CSS
Inline above‑the‑fold CSS, defer non‑critical styles, and compress/priority‑hint critical assets to accelerate first render.
Priorities & Early Hints
Ensure LCP resource gets highest priority and validate network scheduling so critical images and fonts are discovered early.
Crawlability & Indexation
Signals and hygiene
Maintain XML sitemaps, correct robots directives, canonicalization, and fix thin/duplicate pages to focus crawl budget on value pages.
Logs & internal links
Analyze server logs for wasted crawl patterns and strengthen hub‑and‑spoke internal links to speed discovery of cluster content.
Mobile, HTTPS, & Security
Mobile‑first UX
Validate tap targets, layout, and input responsiveness on small screens to preserve engagement and conversion.
Trust baseline
Enforce site‑wide HTTPS, clear policies/contact pages, and stable layouts to reinforce E‑E‑A‑T trust signals.
Measurement & Regression Guardrails
Dashboards
Report weekly LCP/INP/CLS at p75, “Good pages” percentage, and before/after diffs tied to each release.
Alerts & playbooks
Set alert thresholds for metric drift and document remediation steps for LCP, INP, and CLS to shorten recovery cycles.
Executive Checklist
- Convert images to WebP/AVIF with srcset/sizes and explicit dimensions.
- Preconnect to image host and preload the responsive hero image.
- Remove/defer non‑critical JS; break long tasks; adopt Web Workers.
- Inline critical CSS; defer the rest; validate priority of LCP resources.
- Fix sitemaps/robots/canonicals; address thin/duplicate pages.
- Verify mobile usability, site‑wide HTTPS, and trust pages.
- Track p75 CWV weekly; guardrail alerts; document wins and regressions.
Next: deepen execution with Core Web Vitals Mastery, and align structure with Site Architecture & Topic Clusters.
