Customer Review Sentiment Analysis and Chart Reporting - n8n Workflow

Product managers needing automated feedback loops.
Marketing analysts requiring quick insights into customer sentiment.
Businesses using Google Sheets as a low-cost database for operational data.
Users looking for advanced examples of how to integrate AI using an n8n workflow.

• Automation specialists seeking reusable n8n templates for data enrichment.

Manually reading and categorizing thousands of customer reviews is tedious and prone to human error. This n8n workflow solves this by providing a robust, scalable, and intelligent automation system. It reads data from Google Sheets, processes each review using the powerful gpt-4o-mini model via an n8n node configured for sentiment analysis, and then updates the original spreadsheet. After processing, the n8n workflow compiles the results, generates a visually compelling chart using QuickChart, and immediately sends a summarized report via Gmail. This end-to-end automation transforms raw data into actionable intelligence, demonstrating the power of integrating AI services within a robust n8n platform.

The process begins with the manual n8n trigger, which initiates the entire n8n workflow execution.

1. Data Ingestion: The first Google Sheets n8n node reads all existing customer review data from the specified sheet (which must contain 'Review title' and 'Review text' columns).


2. Batch Processing: The n8n node 'Loop Over Items' splits the data into batches, ensuring manageable loads for the subsequent AI step.


3. AI Analysis: For each review, the 'Sentiment Analysis' LangChain n8n node, powered by the 'OpenAI Chat Model' n8n node (configured to use gpt-4o-mini for cost-efficiency), categorizes the input text into 'Positive,' 'Neutral,' or 'Negative.'


4. Data Enrichment: The 'Update Google Sheet' n8n node writes the determined sentiment category back into the sheet, matching the row using the row_number returned during the initial read. This ensures the source data is enriched.


5. Result Aggregation: After the loop completes, another step reads all (now updated) data from the Google Sheet.


6. Chart Generation: A custom Code n8n node 'Extract Number of Answers per Sentiment' tallies the total counts for each category. This result feeds into the 'Generate QuickChart' n8n node, which creates a summary chart image.


7. Reporting: Finally, the 'Send Gmail with Sentiment Chart' n8n node sends the chart image as an attachment to the specified recipient, concluding this sophisticated n8n workflow.

To deploy this expert n8n workflow template, follow these steps:

1. Import the n8n Workflow: Copy the provided JSON data and import it directly into your n8n instance using the 'Import from JSON' function.


2. Google Sheets Setup: You must configure credentials for the Google Sheets n8n node. Replace the placeholder REPLACEWITHYOURGOOGLESHEETSID with the actual ID of your spreadsheet. Ensure your sheet contains the expected columns ('Review title' and 'Review text').


3. OpenAI Credentials: Configure your OpenAI API Key credentials required by the 'OpenAI Chat Model' n8n node. This ensures the sentiment analysis function works correctly.


4. Gmail Configuration: Set up the Gmail OAuth2 credentials. Update the 'Send Gmail with Sentiment Chart' n8n node to replace YOUR[email protected] with the actual email address of the report recipient.


5. Testing: Execute the workflow using the manual n8n trigger to ensure all connections and nodes are functional.

This n8n workflow relies on a mixture of core utility nodes and advanced AI integrations:

When clicking 'Test workflow' (Manual Trigger): This simple n8n trigger node starts the execution of the entire analysis process.
Select Google Sheet (Google Sheets n8n node): Reads the initial batch of data (Review title, Review text) from the spreadsheet using the 'Read' operation.
Loop Over Items (SplitInBatches n8n node): A critical flow control n8n node that iterates over each item fetched from the sheet, processing them one-by-one or in small batches to manage API requests effectively.
Sentiment Analysis (LangChain Sentiment Analysis n8n node): The core AI component. It takes the review text and title as input and uses the linked LLM to classify the text into 'Positive, Neutral, Negative.'
OpenAI Chat Model (LangChain LM ChatOpenAI n8n node): Provides the LLM backend for the sentiment analysis, configured here to use the highly capable and cost-effective gpt-4o-mini model.
Update Google Sheet (Google Sheets n8n node): Updates the row in the spreadsheet, matching on the row_number, and populating the new 'Sentiment' column with the AI-determined category.
Extract Number of Answers per Sentiment (Code n8n node): A custom n8n node using JavaScript to iterate through the results of all updated items and tally the totals for each sentiment category (Positive, Neutral, Negative) for charting purposes.
Generate QuickChart (QuickChart n8n node): Converts the tabulated sentiment counts into a visual chart, ready for email attachment.

• Send Gmail with Sentiment Chart (Gmail n8n node): The final action n8n node, responsible for sending the sentiment summary and the generated QuickChart image to the recipient via email.