Chrome Extension That Tracks Amazon Price History

See price history on every Amazon product page. Get notified when tracked items drop in price.

shoppingintermediate#amazon#price#shopping
PlugThis prompt
Build a Chrome extension called "Amazon Price Tracker." When the user is on an Amazon product page, the extension should: (1) detect the product ID and current price using a content script, (2) save price snapshots to chrome.storage.local with timestamp, (3) inject a small chart below the buy button showing price history for that product, (4) provide a "Track this product" button — when clicked, the extension polls the page weekly via an alarm and notifies the user (Chrome notification) if the price drops below the lowest recorded price, (5) provide an options page listing all tracked products with current prices, lowest seen, and a remove button. Permissions: storage, alarms, notifications, activeTab. Host permissions: https://www.amazon.com/*, https://www.amazon.co.uk/*. Manifest V3.

What this extension does

Tracks Amazon product prices over time. Shows a price history chart on every product page and sends notifications when tracked products drop in price. Stores data locally — no account needed.

How it works

A content script extracts the product ID and price from Amazon DOM. The service worker uses a daily alarm to recheck prices via a fetch to the product URL. Price history is stored in chrome.storage with rolling 90-day retention.

Permissions used: storage, alarms, notifications, activeTab

Host permissions: https://www.amazon.com/*, https://www.amazon.co.uk/*, https://www.amazon.in/*

Who builds this

For frequent Amazon shoppers, gift planners, and anyone tracking expensive items waiting for a price drop. Avoids dependency on third-party tracking services.

How to build it in 3 minutes

  1. Sign in to PlugThis and open the chat input.
  2. Copy the prompt above and paste it into the chat.
  3. PlugThis generates the full Manifest V3 extension in 60-90 seconds.
  4. Download the zip, extract it, and load it via chrome://extensions developer mode.

Build it now, free.

Paste the prompt above into PlugThis and ship your extension in 3 minutes.