Auto-Generate SEO Blog Posts with n8n: Google Autocomplete + GPT-4

Google Sheets topic list → Autocomplete & PAA data collection → GPT-4o draft generation → Write back to sheet with done status

Who

Content operators, freelancers, or small business owners who need to produce SEO-optimized blog posts at scale

You get

Auto-draft ~500-word SEO blog posts based on Google search trends and save them to Google Sheets

You need

n8n · google-sheets · serpapi

Steps

1. Prepare spreadsheet and trigger

   Create a Google Sheet with three columns: Blog Inspiration, Status, Blog Draft. Set trigger to 'row added' or run manually. Complete n8n Google Sheets OAuth2 authorization before first run.

2. Collect search data in parallel

   The workflow reads rows where Status is empty, extracts topic keywords, then runs in parallel: 1) POST to https://seo-api2.onrender.com/get-seo-data for Google Autocomplete suggestions; 2) SerpAPI HTTP Request for People Also Ask questions. Both datasets merge in the Merge node, are cleaned by a Code node, and proceed.

3. GPT-4o generates blog draft

   The Loop Over Items node processes entries one by one. The AI Agent node calls GPT-4o using the source-provided full prompt to generate ~500-word blog posts. Replace the audience placeholder in the prompt with your actual target readers.

   Execution prompt · Source text。Generate Blog Post (AI Agent) node text parameter

   Copy prompt

   =Write a blog post based on the following topic:
   {{ $json.topic }}
   
   Your audience is ___. The tone should feel warm, personal, emotionally resonant, and elegant.
   
   Use the following to guide the content:
   
   Autocomplete keywords:
   {{ $json.autocomplete }}
   Weave these naturally into the blog — not as a list. Use them to inspire talking points, not as SEO stuffing.
   
   People Also Ask questions, Organic Results, or Related Searches:
   {{ $json.paa }}
   Reference or gently answer these questions where they align with the topic.
   
   Content Guidelines:
   
   Generate a warm, SEO-optimized blog title that includes relevant keywords and reflects the post’s focus. Do not use clickbait or vague titles.
   
   Start with a warm, seasonal, or situational hook
   
   Offer client-relevant insights (e.g., wardrobe planning, session timing, location ideas, lifestyle reflections)
   
   Use clear, specific language — avoid filler, clichés, metaphors, or flowery phrasing
   
   Avoid headings unless they add structure
   
   Keep it narrative and around 500 words
   
   End with a gentle call-to-action (e.g., inviting readers to reach out with outfit questions, booking ideas, or planning support)

4. Export to sheet and mark done

   The generated output is written to the Blog Draft column, Status is updated to done, and written back via the Google Sheets node. Loop Over Items continues until all entries are processed.

You are an n8n workflow setup assistant. The user wants to replicate the 'SEO Blog Auto-Generation' template. Assist in this order:
1. Confirm the user has n8n, Google Sheets OAuth2, OpenAI API key, and SerpAPI key;
2. Guide them to create the three-column spreadsheet and import workflow.json;
3. Explain how to fill the audience placeholder in the GPT-4o prompt;
4. Warn about Render API cold-start delay and SerpAPI costs.