SEMrush Content Gap Analysis - Find Missing Keywords

Discover content gaps: keywords your competitors rank for that you don't, and keywords where they outrank you. Live SEMrush data, ranked by opportunity score.

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Two ways to run

Built-in access (no key needed). Leave semrushApiKey empty and the actor uses its own SEMrush access. Built-in runs return up to 10 gap keywords per run, and every row carries a _notice field that says so. Add your own Semrush API key for up to 500 keywords.

Your own Semrush API key. Put your key in semrushApiKey and the full keywordLimit applies (up to 500 keywords per run). SEMrush deducts API units from your plan for every keyword line it returns.

Where to get your key: SEMrush → My Profile → API → Subscription Info

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Quick Start

Built-in access (up to 10 keywords)

{
  "yourDomain": "apify.com",
  "competitors": [
    "zapier.com"
  ],
  "database": "us",
  "gapType": "missing"
}

Your own key (up to 500 keywords)

{
  "semrushApiKey": "YOUR_API_KEY_HERE",
  "yourDomain": "example.com",
  "competitors": [
    "competitor1.com",
    "competitor2.com"
  ],
  "database": "us",
  "gapType": "missing",
  "keywordLimit": 100,
  "minVolume": 100,
  "maxDifficulty": 70,
  "webhookPlatform": "custom"
}

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Input Parameters

Parameter	Type	Default	Required	Description
semrushApiKey	string	-	No	Your own SEMrush API key. Leave empty to use the built-in access (up to 10 keywords per run)
yourDomain	string	-	Yes	Your domain to analyze gaps for (e.g., yoursite.com)
competitors	array	-	Yes	Competitor domains to compare against (up to 4)
database	string	"us"	No	SEMrush database/country to use for data
gapType	string	"missing"	No	Type of content gap to find
keywordLimit	integer	100	No	Max gap keywords to return: up to 500 with your own key, up to 10 on the built-in access
minVolume	integer	100	No	Filter keywords below this monthly volume
maxDifficulty	integer	70	No	Filter keywords above this difficulty (0-100)
webhookUrl	string	-	No	Optional webhook URL to send results (Zapier, Make, n8n, or custom)
webhookPlatform	string	"custom"	No	Select your webhook platform for optimized payload formatting
demoMode	boolean	false	No	Return labeled sample rows without calling SEMrush

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Pricing

This actor uses pay-per-event billing:

Event	When it is charged	Price
Actor start	Once when the run starts, one event per GB of memory (minimum one). At the default 1 GB of memory that is $0.05 per run	$0.05 per GB
Gap Analysis Complete	Per analysis	$0.05
Webhook Sent	Per notification	$0.01
Result	Each item written to the default dataset	$0.00001

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Troubleshooting

Only 10 results

Runs without your own key use the built-in SEMrush access, which returns up to 10 gap keywords per run. Add your own Semrush API key (semrushApiKey) for up to 500 keywords.

Rows marked demo: true

These are sample rows, not real SEMrush data. You get them when no SEMrush key was available for the run, or when the shared key could not serve the request (for example it ran out of API units). Sample runs charge no analysis event and are never sent to your webhook. Add your own semrushApiKey to get live data.

"API error 403" or "Unauthorized"

Your API key is invalid, expired, or doesn't have access to this specific API endpoint. Double-check your key and account permissions.

"API error 429" or "Rate limit"

Too many requests. Wait a minute and try again, or reduce the number of items per run.

No results or empty dataset

Check the run log for error messages. Common causes:

• Invalid input format (check the examples above)
• API key without proper permissions
• The target data doesn't exist or is too small to track

How do I test without an API key?

Leave semrushApiKey empty to get up to 10 live gap keywords on the built-in access. To see the output format without calling SEMrush at all, set demoMode to true: you get labeled sample rows and no analysis event is charged.

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Built by John Rippy | Actor Arsenal