Automate Competitor SEO Content Audits with n8n: Decodo Scraping + Gemini Analysis + Google Sheets Reporting

Input keyword list and brand identity sheet → Decodo searches and scrapes competitor pages → Gemini audits content gaps → outputs structured Action Plan to Google Sheets

Who

SEO or content operators with n8n experience who need batch competitor content audits

You get

Automatically fetch top-ranking competitor pages per keyword, extract body text, and have AI compare against your brand identity to generate structured JSON with Winning Factor, Content Gap, and Action Plan, written to Google Sheets

You need

n8n · google-sheets

Steps

1. Configure global parameters and read brand data

   In the n8n canvas, confirm the trigger (Manual Execution or Schedule Trigger) connects to the Config node. In the Config (Set) node, set target_geo (e.g., United States), target_locale (e.g., en-US), and serp_results_amount (e.g., 10). Config outputs to Brand Info and Data Sourcing: Brand Info reads the Brand Identity tab (single cell with brand mission, USPs, and target audience); Data Sourcing reads the Target Keywords tab (single column Target Keyword).

2. Discover competitors and split URLs

   Data Sourcing output connects to Google Search (Decodo node). This node uses target_geo, target_locale, and serp_results_amount from Config to perform a Google search for each Target Keyword. Results pass to Split to Competitor URLs (Code node), which slices the organic results from Decodo by serp_results_amount and splits each result into its own n8n item with fields keyword, url, title, rank.

   Execution prompt · Source text。JS Code field of the Split to Competitor URLs node

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   // 1. Get configuration, keywords, and search results
   const config = $("Config").first().json;
   const allKeywords = $("Data Sourcing").all();
   const allSearchResults = $("Google Search").all();
   
   // Use the limit from Config, or default to 5 if not found
   const resultLimit = config.serp_results_amount || 10; 
   
   let finalOutput = [];
   
   // 2. Loop through every search result set
   allSearchResults.forEach((searchResult, searchIndex) => {
     
     // Get the keyword from the matching index
     const keyword = allKeywords[searchIndex].json["Target Keyword"] || "Keyword Not Found";
     
     // Navigate the deep Decodo path
     let organicResults = searchResult.json.results[0].content.results.results.organic;
   
     // 3. LIMIT THE RESULTS HERE
     // slice(0, X) takes only the first X items from the array
     const limitedResults = organicResults.slice(0, resultLimit);
   
     // 4. Map each URL (up to the limit) to its own n8n item
     limitedResults.forEach(result => {
       finalOutput.push({
         json: {
           keyword: keyword,
           url: result.url,
           title: result.title,
           rank: result.pos
         },
         // Keeps the internal n8n breadcrumb trail alive
         pairedItem: {
           item: searchIndex
         }
       });
     });
   });
   
   return finalOutput;

3. Scrape and clean content

   Each item from Split to Competitor URLs passes to Universal Scraping (Decodo node) with url from item.json.url and geo from Config.target_geo. Scraping results pass to Extract Body (HTML node) with operation set to extractHtmlContent, dataPropertyName as results[0].content, and extractionValues using cssSelector: body and skipSelectors: img, link to extract body text into Markdown and reduce token noise.

4. AI content audit

   Extract Body output connects to AI Content Auditor (AI Agent node). This node is connected to Google Gemini Chat Model and Structured Output Parser. The user prompt receives the current item's keyword, url, rank, and extracted body; the system message defines a Senior SEO Content Strategist role, requires comparison against Brand Info, and enforces strict JSON output with primary_h1, word_count, top_topics, winning_factor, content_gap, and action_plan.

   Execution prompt · Source text。AI Content Auditor node text (User Prompt) field

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   =Please perform a deep SEO audit on the following competitor content for the keyword: "**{{ $('Split to Competitor URLs').item.json.keyword }}**".
   
   **Competitor URL:** {{ $('Split to Competitor URLs').item.json.url }}
   **Current Rank:** {{ $('Split to Competitor URLs').item.json.rank }}
   
   ---
   **PAGE CONTENT (MARKDOWN):**
   {{ $json.body }}
   ---
   
   Analyze the content and provide the Audit Requirements defined in your system instructions.

   Execution prompt · Source text。AI Content Auditor node options.systemMessage field

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   =You are a Senior SEO Content Strategist. Your mission is to perform a "Search Intent Audit" to find the delta between this competitor and our brand.
   
   ### OUR BRAND IDENTITY (THE GOLD STANDARD):
   {{ $("Brand Info").first().json['Brand Info'] }}
   
   ### INPUT CONTEXT:
   - Target Keyword: {{ $('Split to Competitor URLs').item.json.keyword }}
   - SERP Rank: {{ $('Split to Competitor URLs').item.json.rank }}
   - Content Source: Competitor Markdown extraction.
   
   ### STRATEGIC LOGIC RULES:
   1. THE GAP DEFINITION: A "Content Gap" is NOT just missing text. It is a specific angle, data point, or user-need that OUR BRAND provides (based on the Identity above) which is absent in the competitor's text.
   2. WINNING FACTOR: Identify if they are winning due to "Topical Depth" (long-form), "Technical Authority" (tools/data), or "User Experience" (skimmable headers).
   3. ACTION PLAN: This must be a "Checkmate" instruction. If they are broad, we must be specific. If they are technical, we must be accessible.
   
   ### OUTPUT SCHEMA (STRICT JSON ONLY):
   {
     "primary_h1": "String",
     "word_count": Integer,
     "top_topics": ["Topic 1", "Topic 2", "Topic 3"],
     "winning_factor": "Detailed 1-sentence analysis of their SEO moat.",
     "content_gap": "What specific 'Brand Value' from our identity is missing here?",
     "action_plan": "Specific instruction: 'Write a [Section Type] that focuses on [Brand USP] to outperform their [Competitor Section].'"
   }
   
   ### CONSTRAINTS:
   - No conversational filler. 
   - If the Markdown is empty or invalid, return "Error: No Content".
   - Ensure the 'action_plan' uses the brand voice defined in the Brand Identity.

5. Write results to report sheet

   AI Content Auditor output passes to Strategy Master Writer (Google Sheets node) with operation set to append, sheet pointing to the Competitor Audit Feed tab. Field mapping: Keyword, Competitor URL, Rank, Primary H1, Winning Factor, The Gap, and Action Plan are sourced from upstream node outputs. After writing, the flow connects to Done (NoOp) to finish.

You are reproducing an n8n template: automated competitor SEO content audits. Please confirm you have the following prerequisites before starting:
1) An accessible n8n instance; 2) Google Sheets OAuth2 credentials; 3) A Decodo API key; 4) googlePalmApi credentials for the Gemini node.
Then verify the Config node parameters, the three-tab Google Sheet structure, and that the AI Content Auditor's systemMessage and user prompt are correctly filled. Start with a small test using 1 keyword and 1 competitor to ensure the Structured Output Parser returns valid JSON before running at scale.