Competitor price change monitor
Check public product pages daily and get notified when a price changes.
How it works
Trigger: Schedule — every day
- Read the list of product URLs from a sheet.
- Fetch each page and extract the price with a CSS selector.
- Compare with yesterday's price stored in the sheet.
- Email yourself any changes and update the sheet.
Diagram
Trigger App Logic Code
Code
JavaScript used in the Code step — already included in the template below.
// Mode: Run Once for Each Item
// Watchlist sheet columns: name | url | selector | last_price
const row = $("Read watchlist").item.json;
const newPrice = parseFloat(String($json.price).replace(/[^0-9.]/g, ""));
const oldPrice = parseFloat(row.last_price);
return {
json: {
name: row.name,
url: row.url,
old_price: oldPrice,
last_price: newPrice,
changed: !isNaN(oldPrice) && !isNaN(newPrice) && newPrice !== oldPrice,
},
};Build it
Pick your tool — same automation, step by step.
Copy and paste straight into an n8n canvas (Ctrl+V), or download and use Import from File. Then connect your own credentials and replace every YOUR_… placeholder.
Show code (279 lines)
{
"name": "Competitor price change monitor (Flowngn)",
"nodes": [
{
"parameters": {
"content": "## Competitor price change monitor\nCheck public product pages daily and get notified when a price changes.\n\n**Setup**\n1. Open each node and connect your own credentials.\n2. Replace every YOUR_… placeholder.\n3. Test once, then activate.\n\nFree template from Flowngn",
"height": 260,
"width": 340
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Setup notes",
"type": "n8n-nodes-base.stickyNote",
"typeVersion": 1,
"position": [
-420,
-60
]
},
{
"parameters": {
"rule": {
"interval": [
{
"triggerAtHour": 10
}
]
}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Every day 10:00",
"type": "n8n-nodes-base.scheduleTrigger",
"typeVersion": 1.2,
"position": [
0,
0
]
},
{
"parameters": {
"operation": "read",
"documentId": {
"__rl": true,
"value": "YOUR_SPREADSHEET_ID",
"mode": "id"
},
"sheetName": {
"__rl": true,
"value": "Watchlist",
"mode": "name"
},
"options": {}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Read watchlist",
"type": "n8n-nodes-base.googleSheets",
"typeVersion": 4.5,
"position": [
300,
0
]
},
{
"parameters": {
"url": "={{ $json.url }}",
"options": {}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Fetch product page",
"type": "n8n-nodes-base.httpRequest",
"typeVersion": 4.2,
"position": [
600,
0
]
},
{
"parameters": {
"operation": "extractHtmlContent",
"extractionValues": {
"values": [
{
"key": "price",
"cssSelector": "={{ $('Read watchlist').item.json.selector }}"
}
]
},
"options": {
"trimValues": true
}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Extract price",
"type": "n8n-nodes-base.html",
"typeVersion": 1.2,
"position": [
900,
0
]
},
{
"parameters": {
"jsCode": "// Mode: Run Once for Each Item\n// Watchlist sheet columns: name | url | selector | last_price\nconst row = $(\"Read watchlist\").item.json;\nconst newPrice = parseFloat(String($json.price).replace(/[^0-9.]/g, \"\"));\nconst oldPrice = parseFloat(row.last_price);\n\nreturn {\n json: {\n name: row.name,\n url: row.url,\n old_price: oldPrice,\n last_price: newPrice,\n changed: !isNaN(oldPrice) && !isNaN(newPrice) && newPrice !== oldPrice,\n },\n};",
"mode": "runOnceForEachItem"
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Compare prices",
"type": "n8n-nodes-base.code",
"typeVersion": 2,
"position": [
1200,
0
]
},
{
"parameters": {
"operation": "update",
"documentId": {
"__rl": true,
"value": "YOUR_SPREADSHEET_ID",
"mode": "id"
},
"sheetName": {
"__rl": true,
"value": "Watchlist",
"mode": "name"
},
"columns": {
"mappingMode": "autoMapInputData",
"value": {},
"matchingColumns": [
"url"
]
},
"options": {}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Save new price",
"type": "n8n-nodes-base.googleSheets",
"typeVersion": 4.5,
"position": [
1500,
0
]
},
{
"parameters": {
"conditions": {
"options": {
"caseSensitive": true,
"leftValue": "",
"typeValidation": "loose"
},
"conditions": [
{
"id": "c1",
"leftValue": "={{ $json.changed }}",
"rightValue": "",
"operator": {
"type": "boolean",
"operation": "true",
"singleValue": true
}
}
],
"combinator": "and"
},
"options": {}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Price changed?",
"type": "n8n-nodes-base.if",
"typeVersion": 2.2,
"position": [
1500,
220
]
},
{
"parameters": {
"sendTo": "you@yourcompany.com",
"subject": "=Price change: {{ $json.name }}",
"emailType": "text",
"message": "={{ $json.name }} changed from {{ $json.old_price }} to {{ $json.last_price }}\n{{ $json.url }}",
"options": {
"appendAttribution": false
}
},
"id": "2c527986-e9cb-4ca8-a3d3-d49e3763bac8",
"name": "Email me",
"type": "n8n-nodes-base.gmail",
"typeVersion": 2.1,
"position": [
1800,
0
]
}
],
"connections": {
"Every day 10:00": {
"main": [
[
{
"node": "Read watchlist",
"type": "main",
"index": 0
}
]
]
},
"Read watchlist": {
"main": [
[
{
"node": "Fetch product page",
"type": "main",
"index": 0
}
]
]
},
"Fetch product page": {
"main": [
[
{
"node": "Extract price",
"type": "main",
"index": 0
}
]
]
},
"Extract price": {
"main": [
[
{
"node": "Compare prices",
"type": "main",
"index": 0
}
]
]
},
"Compare prices": {
"main": [
[
{
"node": "Save new price",
"type": "main",
"index": 0
},
{
"node": "Price changed?",
"type": "main",
"index": 0
}
]
]
},
"Price changed?": {
"main": [
[
{
"node": "Email me",
"type": "main",
"index": 0
}
]
]
}
},
"pinData": {},
"settings": {
"executionOrder": "v1"
},
"meta": {
"templateCredsSetupCompleted": false
},
"tags": []
}In Make, create a new scenario and add these modules in order:
- Schedule the scenario: Every day 10:00
- Google Sheets › Search Rows
- HTTP › Make a request
- Text parser › HTML to text (or Match pattern)
- Tools › Set variable / Iterator + Array aggregator (same logic as the Code step)
- Google Sheets › Update a Row
- Filter on the next route: “Price changed?”
- If yesGmail › Send an Email
- Every module run uses Make operations — the free plan includes a monthly quota.
- Make's built-in functions (map, sum, formatDate…) can replace most Code steps; for complex logic use a code module.
- Module and step names can differ slightly as Make and Zapier update their apps.
In Zapier, create a new Zap and add these steps in order:
- Schedule by Zapier — Every day 10:00
- Google Sheets — Lookup Spreadsheet Rows (or Code by Zapier)
- Webhooks by Zapier — GET
- Formatter by Zapier — Text › Extract
- Code by Zapier — Run JavaScript (paste the code from the Code section)
- Google Sheets — Update Spreadsheet Row
- Filter by Zapier: “Price changed?”
- If yesGmail — Send Email
- Zaps with more than two steps need a paid Zapier plan.
- Webhooks, Filters/Paths and Code by Zapier are premium features on some Zapier plans.
- Code by Zapier runs JavaScript: reuse the code shown above, reading inputs from inputData instead of $json.
- Module and step names can differ slightly as Make and Zapier update their apps.
Tips
- Only check a handful of pages, once a day, and respect each site's terms and robots.txt.
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