SEMrush Content Gap Analysis - Find Missing Keywords

"Discover Keywords Your Competitors Rank For That You Don't" by John Rippy | johnrippy.link

🏆 2025 Zapier Automation Hero of the Year — Project Phoenix: A 95-step AI sales pipeline cutting development time by 50%. Read more →

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Find content gaps and untapped keyword opportunities using SEMrush data and your own API key (BYOK). Discover keywords your competitors rank for that you don't, and identify weak spots where you rank lower.

What You Get

Gap Types

• Missing: Keywords competitors rank for, you don't rank at all
• Weak: Keywords where you rank lower than competitors
• Untapped: Low difficulty opportunities with high volume

Keyword Data

• Search volume
• Keyword difficulty
• CPC and competition
• Your ranking position
• Each competitor's position
• Opportunity score (calculated)

Opportunity Score

A calculated metric that factors in:

• Search volume (higher = better)
• Keyword difficulty (lower = better)
• Number of competitors ranking (more = validated opportunity)

Input Parameters

Parameter	Type	Default	Description
semrushApiKey	string	-	Your SEMrush API key
yourDomain	string	-	Your domain
competitors	array	-	Competitor domains (up to 4)
database	string	us	Country database
gapType	string	missing	missing, weak, untapped, all
keywordLimit	integer	100	Max keywords to return
minVolume	integer	100	Minimum search volume
maxDifficulty	integer	70	Maximum keyword difficulty
webhookUrl	string	-	Webhook endpoint
webhookPlatform	string	custom	zapier, make, n8n, custom
demoMode	boolean	true	Return sample data

Example Usage

Basic Gap Analysis

{
  "semrushApiKey": "your-api-key",
  "yourDomain": "yoursite.com",
  "competitors": ["competitor1.com", "competitor2.com"],
  "database": "us",
  "demoMode": false
}

Missing Keywords Only

{
  "semrushApiKey": "your-api-key",
  "yourDomain": "yoursite.com",
  "competitors": ["competitor1.com", "competitor2.com"],
  "gapType": "missing",
  "minVolume": 500,
  "demoMode": false
}

Low-Hanging Fruit

{
  "semrushApiKey": "your-api-key",
  "yourDomain": "yoursite.com",
  "competitors": ["competitor1.com", "competitor2.com"],
  "minVolume": 200,
  "maxDifficulty": 40,
  "keywordLimit": 200,
  "demoMode": false
}

With Webhook

{
  "semrushApiKey": "your-api-key",
  "yourDomain": "client-site.com",
  "competitors": ["competitor1.com"],
  "webhookUrl": "https://hooks.zapier.com/hooks/catch/123/abc",
  "webhookPlatform": "zapier",
  "demoMode": false
}

Output Example

{
  "keyword": "project management software comparison",
  "gapType": "missing",
  "searchVolume": 4800,
  "keywordDifficulty": 52,
  "cpc": 6.50,
  "competition": 0.85,
  "yourPosition": "Not ranking",
  "yourPositionValue": 0,
  "competitorPositions": {
    "competitor1.com": 3,
    "competitor2.com": 8
  },
  "bestCompetitorPosition": 3,
  "competitorsRanking": 2,
  "opportunityScore": 18.2,
  "yourDomain": "yoursite.com",
  "database": "us",
  "analysisDate": "2025-01-01T12:00:00.000Z"
}

Gap Types Explained

Gap Type	Meaning	Action
Missing	Competitors rank, you don't	Create new content
Weak	You rank lower than competitors	Optimize existing content
Untapped	Low competition opportunities	Quick win potential

SEMrush API Units

API Call	Units
Domain Domains (gap)	40 per request

Note: Units vary based on domains and keywords returned.

Pricing

Event	Description	Price
Actor start	Base cost per run	$0.05
Gap analysis complete	Per analysis	$0.05
Webhook sent	Per notification	$0.01

Use Cases

Content Strategy

Build a content calendar based on proven competitor topics.

SEO Optimization

Find quick wins to improve existing content.

Competitive Intelligence

Understand competitor content strategy.

Client Proposals

Show prospects what opportunities they're missing.

Content Auditing

Identify gaps in your content coverage.

Getting Your SEMrush API Key

1. Log in to SEMrush
2. Go to My Profile → API → Subscription Info
3. Copy your API key
4. Paste into the semrushApiKey input field

Limitations

• Maximum 4 competitor domains per analysis
• API rate limits depend on your SEMrush subscription
• Results depend on SEMrush database coverage

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Built by John Rippy | johnrippy.link

🏆 2025 Zapier Automation Hero of the Year — Project Phoenix: A 95-step AI sales pipeline cutting development time by 50%. Read more →

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Keywords

semrush content gap, keyword gap analysis, competitor keywords, missing keywords, seo gap analysis, content opportunities, semrush api, byok semrush, keyword opportunities, zapier integration, make integration, n8n integration