What Is a Price Tracker and How Do Price History and Drop Alerts Help You Save?
A price tracker is a tool that records how a product's price changes over time and can notify you when it drops or when an out-of-stock item returns. It's useful when you're deciding whether a current price is actually a good deal, or when you want to buy something later without checking the page every day. On Glass It (glassit.co), this works in two connected ways: a price history checker that shows past prices for a product URL, and price drop / back-in-stock alerts that watch the item for you.
Price history vs. price drop alerts: what each one does
These are two different jobs, and knowing which you need saves time.
| Feature | What it answers | When to use it |
|---|---|---|
| Price history check | "Has this price been lower before, and what's the typical price?" | Before buying, to judge if today's price is good |
| Price drop alert | "Tell me when the price falls below where it is now." | When you're not ready to buy yet |
| Back-in-stock alert | "Tell me when this sold-out item is available again." | When the product is unavailable |
Price history is a lookup — you get an answer immediately. Alerts are a subscription — you set them and wait.
How to check a product's price history
The site's core instruction is simple: enter the product's webpage URL. That's the input the price history checker is built around.
- Copy the full URL of the product page from the retailer (for example, an Amazon, Walmart, or Udemy listing).
- Paste it into the price history checker on glassit.co.
- The tool returns the recorded price history for that product, so you can compare the current price against its past range.
The expected result is a view of how the price has moved, which lets you see whether the current number is near a low or near a high. If a store isn't covered, the lookup won't return history for that URL — in that case, check whether the retailer appears in the supported list below before assuming the tool failed.
How to read price history data to judge a deal
Raw price history is only useful if you know what to look for. Glass It's own listings show the pattern clearly — each tracked item displays a current price, a reference (average or original) price, the retailer, and a percentage below average.
From the site's "Price Drops In The Last 30 Days" section, real examples include:
- Evening Bags (DHgate): $88.63 vs. $245.78 — 64% below average
- PIERCED MULTI-STRAP HEELED SANDAL (Tory Burch): $179.00 vs. $259.05 — 31% below average
- iPhone 12 Pro 128 GB (Back Market UK): £219.00 vs. £301.68 — 27% below average
- New Balance 9060 (Snipes): $89.99 vs. $121.03 — 26% below average
- NVIDIA A100 40GB (eBay): $5,859.99 vs. $7,072.48 — 17% below average
When you read a history chart, focus on three numbers:
- Lowest recorded price — the floor. If today's price is close to it, it's a strong buy signal.
- Average price — the baseline. A "X% below average" figure tells you how far today's price sits under the norm.
- Current discount vs. how often it drops — a product that hits its low every few weeks is worth waiting on; one that rarely drops may be worth buying now.
The "Lowest Price Check" heading on the site reflects exactly this use: confirming whether the current price is at or near its historical low.
How to set price drop and back-in-stock alerts
Alerts replace manual checking. The site describes them as price drop alerts and back in stock alerts.
- Find the product you want to watch (via its URL, as with the history check).
- Set an alert for a price drop, a back-in-stock notification, or both.
- Wait for the notification instead of refreshing the page.
The practical benefit: for a sold-out item like a limited sneaker or a GPU, a back-in-stock alert means you're told the moment it's available rather than discovering it after it sells out again. For a price drop alert, you choose the target and get notified when the price reaches it.
Which stores are supported
Glass It lists a broad set of supported trackers, including:
General retail: Amazon, Walmart, Target, Best Buy, Costco, Home Depot, Lowe's, IKEA, Wayfair, West Elm, Kohl's, Macy's, Nike, Newegg, Etsy, Argos, Canadian Tire, B&H, Back Market, Thomann, Stockx, Bulk Ammo Marketplaces & regional: AJIO, Flipkart, Meesho, Myntra, Shopee, Zalando Digital & courses: Udemy, Google Play, App Store Real estate: Zillow, Trulia
The site also shows a "Show All Price Trackers" option, so the visible list may not be the full set. If your store isn't listed, the price history lookup for that URL likely won't return data — the workaround is to check whether the retailer appears under "Show All," or to use a store that is covered for the same product category.
What to expect in practice
The site's "Popular Tracks" show how much prices can vary on the same item:
- The Complete Full-Stack Web Development Bootcamp (Udemy): $124.99 → $28.34
- 100 Days of Code: The Complete Python Pro Bootcamp (Udemy): $129.99 → $34.81
- The Complete Python Bootcamp From Zero to Hero (Udemy): $199.99 → $38.21
These gaps are exactly why price history matters: a course listed at $199.99 has sold for under $40, so paying full price without checking history means overpaying. The same logic applies to physical goods — the 30-day drop list shows discounts ranging from 17% to 64% below average, meaning the "normal" price is often not the price you should pay.
Use a price history check before any non-urgent purchase to see the real range, and set a price drop or back-in-stock alert when you're willing to wait for a better number.