The fastest way to find SEO opportunities is to compare websites SEO side by side against your direct competitors. When you compare websites SEO metrics — traffic, rankings, backlinks, and content — your competitors have already done the hard work of figuring out what Google rewards in your niche. This guide shows you exactly how to do this for free and what to do with the results.
⚔️ Free tool: Enter two domains at seobilitycheck.com/competitor-comparison-tool/ for an instant side-by-side analysis — no signup needed.
Why You Should Compare Websites SEO
Competitor analysis gives you intelligence no solo audit can provide. Competitors have already validated what content, keywords, and link strategies work in your niche. As documented in Backlinko’s competitor analysis guide, the most actionable opportunities come from gap analysis — finding what competitors have that you do not.
- Keyword gaps: Keywords they rank for that you do not — easiest quick-win content opportunities
- Content gaps: Topics they cover that you have not written about yet
- Backlink opportunities: Sites linking to them but not to you — proven link targets
- Format insights: What content formats earn rankings in your niche
- Performance benchmarks: Whether your page speed and technical SEO are ahead or behind
What to Compare — Full Metrics Breakdown
A complete analysis covers seven core metrics:
| Metric | Why It Matters | Free Tool |
|---|---|---|
| Organic traffic estimate | How much search traffic each site gets | SeobilityCheck Traffic Checker |
| Domain authority | Overall site strength — overall site strength | Moz Link Explorer (free) |
| Top pages | Their best-performing content | Ubersuggest (3 free/day) |
| Keyword rankings | What they rank for that you do not | Google Search (manual) |
| Content structure | How they format content that ranks | Manual review |
| Page speed / CWV | Technical advantage or disadvantage | Google PageSpeed Insights |
| Backlink profile | Link building gap analysis | Ahrefs free tools |
How to Compare Websites SEO — Step by Step
Follow these five steps to run a complete comparison at no cost:
Compare Traffic Estimates
Use SeobilityCheck Traffic Checker on both your domain and your competitor’s domain. This is the first number to check — who gets more organic visits and on which pages.
Run a Side-by-Side SEO Comparison
Use SeobilityCheck Competitor Comparison Tool — enter both URLs for a side-by-side analysis of content quality, speed scores, and on-page factors.
Keyword Gap Analysis
Google each of your target keywords and note which competitor ranks in the top 5. For each keyword they rank for and you do not, you have identified a gap to fill with new content.
Content Gap Analysis
Browse the competitor’s blog and note topics they cover that you have not written about. More topical coverage usually means stronger overall rankings.
Page Speed Comparison
Run both sites through Google PageSpeed Insights. A speed advantage is a direct ranking advantage — Core Web Vitals are confirmed ranking signals.
How to Act on Your Results
Once you have the data, prioritise actions by impact:
- They have more organic traffic: Identify their top 10 pages and create better, more comprehensive versions of that content
- They have more backlinks: Find who links to them using free tools and pitch those same sites with superior content
- They rank for keywords you do not: Create dedicated pages targeting those keyword gaps — these are your most direct SEO opportunities
- Their pages load faster: Run PageSpeed Insights and implement the highest-impact recommendations
- They have more content: Build a content calendar from their topic coverage — fill each gap systematically
✅ Tip: Focus on gaps where you can realistically compete. If a competitor has 10x your domain authority, target their long-tail keyword rankings first — these are lower competition than their head terms.
When to Compare Websites SEO
- When launching a new site — benchmark against the top 3 competitors before writing a word
- After a traffic drop — check if a competitor improved or outranked you
- When planning your content calendar — find content gaps systematically
- During link building — identify shared backlink opportunities
- Monthly as part of regular SEO monitoring — track the gap closing over time
- Before a site redesign — understand what is working for competitors before changing your own structure
Free Tools for Competitor SEO Comparison
Every step can be done without a paid subscription, using tools referenced in Moz’s competitor research guide:
| Tool | Use |
|---|---|
| SeobilityCheck Competitor Comparison | Full side-by-side on-page and technical comparison |
| SeobilityCheck Traffic Checker | Organic traffic estimate for any domain |
| Google PageSpeed Insights | Speed and Core Web Vitals comparison |
| Moz Link Explorer (free) | Domain authority and backlink comparison |
| Ubersuggest (3 free/day) | Top pages and keyword rankings comparison |
| Google Search (manual) | Keyword gap check — search your target keywords and note who ranks |