On-site optimization: how to prepare your website for performance and conversions

What is on-site optimization and why it matters

On-site optimization (or on-page SEO) encompasses all actions within the website that influence visibility in search engines and user behavior. Includes technical elements (speed, indexing), content (structure, relevance, E-E-A-A-T) and UX/CRO (page clarity, call-to-action, forms).

On-site SEO audit - where to start

A well-structured audit gives you a clear roadmap: what's blocking organic growth, what's slowing down your site, and how you can turn traffic into customers.

Speed and Vitals Web Core - performance you can feel

A fast website is a website that converts. Optimizing site speed and Core Web Vitals influence both rankings and the actual user experience.

Images: modern formats and smart upload

• Use WebP or AVIF (with PNG/JPG fallback where necessary).
• Activate lazy loading for non-critical images and preload for the LCP image.
• Generate responsive dimensions (srcset, sizes) and compress without visible loss.
• Avoid images in CSS for critical elements; prefer img with explicit sizes to reduce CLS.

Cache, CDN and compression

• Activate caching server and page level (e.g. Nginx FastCGI, WordPress caching plugin).
• Serve content by CDN (Cloudflare, BunnyCDN) for global low latency.
• Use Brotli or GZIP for compressing text files.

CSS/JS: minify, split and load

• Minify and just combine carefully resources; separate critical CSS and run the rest deferred.
• Upload JS non-critic with defer/async; avoids unnecessary polyfills for modern browsers.
• Remove Unused CSS (purge) and heavy JS libraries if native alternatives exist.

Hosting and architecture

• Choose a efficient hosting (PHP 8.x, HTTP/2 or HTTP/3, OPcache).
• Optimize your database, use object cache (Redis/Memcached) and limits heavy plugins.
• Activate preconnect/dns-prefetch to critical third domains.

Content and on-page SEO: how to structure your relevance

Search engines look for clarity, consistency and authority. Get it right title tag, meta description, semantics H1-H3, and adds schema markup to enable rich snippets.

• Writing for people, mapping search intent (informational, transactional, navigational).
• Grow E-E-A-A-T (Experience, Expertise, Authoritativeness, Trust): identifiable author, cited sources, trusted pages (About, Contact, Policies).
• Use interlinking to guide users and crawlers to key pages (silos, categories, money pages).
• Add FAQ scheme to grab extra SERP space where relevant.

Information architecture and interlinking

A user-friendly website is also easy for Google to understand. Build a clear architecture and maintain natural internal links with descriptive anchors.

• Organize content into thematic silos (ex: category > subcategory > article).
• Add breadcrumbs and make sure URLs are clean, descriptive and consistent.
• Repair orphan pages (no internal links) and limits depth of clicks (ideally under 3 clicks to key content).
• Set canonical links to avoid duplicates, especially on pages with filters.

Essential technical SEO: indexing, signals and cleanup

• Robots.txt: allow crawling for public sections; block technical folders. Do not block CSS/JS required for rendering.
• XML Sitemap: updated, submitted to Search Console; includes indexable canonical URLs only.
• 301 redirects: for old URLs; avoid chains/loops; relevant 1:1 mapping.
• Canonical: self-referential on canonical pages; pay attention to pagination and URL parameters.
• Hreflang (multilingual site): correlated in pairs, pointed to the correct regional versions (e.g. en-RO, en-GB); all versions must refer to each other.
• HTTPS mandatory; 301 redirect from HTTP; unique URL (www vs non-www).
• Pages 404 custom: useful, easy, with links to relevant sections.
• Parameters: controls indexing to pages with filters/sorts; avoids duplicates.
• Accessibility: contrast, font size, visible focus, form labels; helps UX and SEO.

UX and conversions (CRO): turn visitors into customers

An SEO-optimized site attracts visits; a conversion-optimized site monetizes them. Focus on clarity, minimal friction and trust.

• Running A/B testing for headline, CTA, layout (tools: VWO, Optimizely, Convert), measured in GA4.
• Use heatmaps, recordings and on-site surveys (Hotjar, Clarity) to detect real blockages.
• Think mobile-first: simple navigation, clear menus, large buttons, field-friendly keyboards.

Continuous measurement, reporting and iteration

What you don't measure you can't improve. Define KPIs, tools and a review rhythm.

• Set in GA4 events and conversions for CTA clicks, form submit, add-to-cart, checkout step.
• Build dashboards in Looker Studio; exports to BigQuery for advanced analysis.
• Monitor Core Web Vitals reports (Chrome UX Report) and Search Console errors.
• Sets a cycle of monthly optimization: hypothesis > test > implement > measure.

Case study (summary): online cosmetics shop

Context: WooCommerce store, poor times on mobile and drop in conversions. Objective: improve Core Web Vitals, clarify funnel and increase conversion rates.

• Technical: passing images to WebP, critical CSS, defer JS, CDN + cache, plugin cleanup.
• On-page SEO: rewriting titles/meta, adding Product and BreadcrumbList schema, interlinking in categories.
• CRO: contrasting CTA, trust badges, simplified checkout, microcopy for delivery/return.

Quick practical tips for on-site optimization

• Don't rely on lab results: validate in field data (CrUX) and on real devices.
• Prioritize impact: start with pages that generate 80% of revenue/leads.
• Clean regularly redirects and repair broken links.
• Keep semantic consistency: clear H1, correct hierarchy, easy-to-scan content.
• Check daily Search Console for indexing errors and rich results problems.
• Update evergreen content with new facts, examples and FAQs.
• Respect YMYL (Your Money Your Life): transparency, expertise, verified sources.
• Document changes (changelog) to correlate updates with KPI evolution.

Experience from the field: what works consistently

Of the projects optimized in recent years, three things have had the biggest impact:

1. Reducing JS complexity: replacing heavy libraries with native solutions has improved INP and stability.
2. Strategic interlinkingRelevant internal links, natural anchors and clear navigation serifs increased time on page and visibility on long-tail keywords.
3. Message + proof: adjusting the headline and adding social proof close to the CTA increased CTR on landing pages.

Short checklist for launch or relaunch

• Core Web Vitals „green” on mobile in real reports.
• Title/Meta unique, H1 unique per page, relevant schema valid.
• Robots.txt, XML sitemap, canonicals, hreflang (where applicable) correct.
• Redirect map 301 completely, no chains, no uncontrolled 404.
• Forms tested end-to-end; GA4 events configured.
• Breadcrumbs, clear navigation, dynamic interlinking to money pages.
• Visible trust policies and pages (Contact, About, Terms, Privacy).

Frequently Asked Questions

On-site optimization immediately helps ranking? It depends on the type of change. Technical corrections (indexing, canonicalization) can take effect quickly; content and E-E-A-T changes can take weeks-months.

Is on-site optimization without link building enough? For niches with little competition, sometimes yes. In competitive markets, you also need authority (links, brand, PR).

What if I have a low PSI score but users convert? Prioritize real experience; however, optimize issues that clearly affect field data and UX.