How-To Guides/Track Price Changes

How to Track Price Changes on Any Website Automatically

A step-by-step tutorial for setting up automated price monitoring with OnChange. Learn how to target price elements, configure alerts, and build a price tracking workflow that runs on autopilot.

Last updated: April 202610 min read

Before You Start

To follow this tutorial, you will need:

A free OnChange account (sign up at onchange.sairo.app/signup)
The URL of a product page with a visible price
A modern web browser with developer tools (Chrome, Firefox, Edge, or Safari)

Step 1: Find the Price Element on the Page

Before creating a monitor, you need to identify the CSS selector for the price element on your target product page. This tells OnChange exactly which part of the page to watch.

Using Browser Developer Tools

1. Open the product page in your browser.
2. Right-click on the price and select "Inspect" or "Inspect Element."
3. The developer tools panel opens with the price element highlighted in the HTML.
4. Look at the element's class names and attributes. For example, you might see something like <span class="price-current">$29.99</span>.
5. The CSS selector in this case would be .price-current.

Common Price Selectors

.price -- generic price class

.product-price -- product-specific price

[data-price] -- data attribute

.price-current -- current price (vs sale)

#priceblock_ourprice -- Amazon-style ID

.a-price .a-offscreen -- nested price

Step 2: Create a New Monitor in OnChange

Click 'New Monitor'

From your dashboard, click the New Monitor button to open the monitor creation form.

Paste the product page URL

Enter the full URL of the product page. Make sure it is the canonical product URL, not a search results page or a shortened link.

Select 'CSS Selector' monitoring mode

Choose CSS Selector as the monitoring type. This tells OnChange to watch only the specific element you define, ignoring everything else on the page.

Enter your CSS selector

Type the CSS selector you identified in Step 1. Alternatively, use the built-in visual picker to click directly on the price element in the page preview.

Verify the captured content

OnChange shows a preview of the text content captured by your selector. Confirm it shows the correct price value before proceeding.

Step 3: Set the Check Frequency

Choose how often OnChange should check the product page for price changes. The right interval depends on what you are tracking.

10-60 seconds

Best for flash sales, lightning deals, and time-sensitive promotions where minutes matter.

5-30 minutes

Best for routine price tracking where you want to catch changes within the hour but do not need second-level speed.

1-24 hours

Best for long-term price monitoring, seasonal trend analysis, or tracking products where prices rarely change.

Step 4: Configure Your Alerts

Decide where you want to receive price change notifications. You can configure multiple channels for the same monitor.

Email notifications

Receive an email with the old price, new price, percentage change, and a direct link to the product page. Good for individual tracking.

Slack channel alerts

Post price changes to a dedicated Slack channel so your whole team sees them. See our Slack setup guide for configuration details.

Discord webhooks

Send price alerts to a Discord channel. Useful for deal-hunting communities or team channels focused on procurement.

Custom webhook

Forward price change data to any HTTP endpoint. Connect to Zapier, Google Sheets, internal dashboards, or custom price tracking databases.

Step 5: Activate and Verify

Save your monitor configuration and verify it is working correctly.

Save the monitor. OnChange captures the initial baseline price immediately.

Run a manual check to verify the monitor is capturing the correct content.

Confirm the price value shown in the dashboard matches the actual price on the product page.

Wait for a natural price change, or test by temporarily changing the selector to a different element to verify alerts are delivered.

Advanced Price Tracking Tips

Track Multiple Variants

If a product has multiple variants (sizes, colors, configurations) with different prices, create a separate monitor for each variant URL. This gives you granular tracking per SKU and prevents confusing price changes that are actually just variant switches.

Handle Dynamic Price Formats

Some e-commerce sites render prices using JavaScript after the initial page load. OnChange uses a headless browser that executes JavaScript, so dynamically rendered prices are captured correctly. If the price is fetched via an API call, consider monitoring the API endpoint directly using API monitoring.

Avoid Currency & Locale Issues

If the site displays different prices based on your location or currency, make sure OnChange is accessing the page in the same locale configuration you care about. This prevents false alerts caused by currency conversions or regional pricing differences.

Start Tracking Prices Now

Create your free account and set up your first price monitor in under two minutes. No credit card required.

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