Optimize Instagram Hashtags with GPT-4o & Real Engagement Data via Graph API

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Built by Shun Nakayama Shun Nakayama
Created on June 13, 2026

Description

Instagram Hashtag Generator Workflow

This workflow automatically generates optimal hashtags for your Instagram posts by analyzing captions and fetching real-time engagement data.

Key Features
100% Official API & Free**: Uses ONLY the official Instagram Graph API. No expensive third-party tools or risky scraping methods are required.
Safe & Reliable**: Relying on the official API ensures compliance and long-term stability.
Smart Caching**: Includes a Google Sheets caching mechanism to maximize the value of the official API's rate limits (30 searches/7 days).

Workflow Overview

Caption Input: Set your caption manually or via a workflow trigger.
AI Suggestions: GPT-4o-mini analyzes the caption and suggests 10 relevant hashtags, balancing popular (big words) and niche keywords.
Official API Search (Instagram Graph API):
Fetches Hashtag IDs using the ig_hashtag_search endpoint.
Retrieves engagement metrics (Average Likes, Average Comments) using the ID.
Selection & Sorting:
Sorts candidates by engagement metrics.
Selects the top 5 most effective hashtags that balance relevance and engagement.
Output: Returns the final list of hashtags as text.

Setup Steps

Import to n8n:
Copy the content of workflow_hashtag_generator.json and paste it into your n8n canvas, or import the file directly.

Credentials:
OpenAI account: Connect your OpenAI credentials.
Facebook Graph account: Connect your Facebook Graph API credentials.

Configuration:
Instagram Business ID: Update the YOUR_INSTAGRAM_BUSINESS_ACCOUNT_ID placeholder in the Get Hashtag Info and Get Hashtag Metrics nodes with your actual Business Account ID.
Google Spreadsheet ID: Update the YOUR_SPREADSHEET_ID placeholder in the Fetch Cached Hashtags and Save to Cache nodes.

Adjustments:
Filter Logic: You can adjust the sorting or filtering logic in the Aggregate & Rank Candidates node's JavaScript code (e.g., exclude tags with fewer than 1000 posts) if needed.

Important Notes on API Limits
The official Instagram Hashtag Search API (ig_hashtag_search) allows for 30 unique hashtag queries per rolling 7-day period.
Why this is fine**: This workflow caches results in Google Sheets. Once a tag is fetched, it doesn't need to be queried again for a while, allowing you to build up a large database of tags over time without hitting the limit.
Recommendation**: Use mock data during initial testing to save your API quota.

Nodes Used (5)

Basic LLM Chain
@n8n/n8n-nodes-langchain.chainLlm
Code
n8n-nodes-base.code
Facebook Graph API
n8n-nodes-base.facebookGraphApi
Google Sheets
n8n-nodes-base.googleSheets
OpenAI Chat Model
@n8n/n8n-nodes-langchain.lmChatOpenAi