How to Monitor a Web Page for Price Drops and Restocks
Waiting for a price to fall or an item to restock? Instead of checking the product page every day, have it watched automatically and get an email when the price or stock status changes.
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Free plan · 10 URLs · hourly checks · 2 AI summaries/mo · no credit card
Updated
Step by step
Open the product page and find the price
Use the product's own page, with any size or colour options already selected if the shop puts them in the URL.
Find a CSS selector for the price
Right-click the price, choose Inspect, and look for an id or class on the price element — often something like #price, .price, or .product-price. For restocks, do the same for the "Out of stock" or "Add to cart" text.
Add the page in Site Monitor
Click Add site, paste the product URL, and give it a name like "Headphones — price".
Turn on change detection with your selector
Tick "Notify me when page content changes" and enter the selector, for example #price, .stock. Only those elements are compared, so new reviews, recommendations, or banners elsewhere on the page are ignored.
Pick a check interval
Hourly checks (Free plan) are enough for most price watching. For fast-selling restocks, paid plans check as often as every 5 minutes.
Act on the alert
When the price or stock text changes you get an email naming the product page. Open the dashboard to see the AI summary of what changed, then head to the shop.
You choose which alerts each URL sends — downtime, content changes, slow responses — and we email you when they happen.
What you'll need
- The product page URL (publicly visible, no login)
- A CSS selector for the price and/or stock status
- An email address for alerts
Why a selector matters for shopping pages
Product pages are some of the noisiest pages on the web: reviews get added, "people also bought" carousels shuffle, delivery estimates update by the hour, and promotional banners come and go. Watching the whole page would alert you for all of that.
Scoping the watch to the price (and, if you want, the stock status) means you only hear about the change you care about. Add both selectors separated by a comma to cover price drops and restocks with a single monitor.
Tracking several products or shops
Add one site per product page. The Free plan covers 10 URLs, which is plenty for a wishlist. Give each one a clear display name, because that name is what you'll see in alert emails.
If the same product is sold by several shops, watch each shop's page separately — you'll find out whichever one moves first.
When the price doesn't show up
Some shops render prices with JavaScript, or show different prices by region or after login. Site Monitor can render pages in a headless browser so JavaScript-loaded prices are included, but it can't read prices that are only visible to signed-in customers.
If your selector stops matching after a site redesign, update it on the site's page in your dashboard — the page will be compared using the new selector from the next check.
Worked example: finding the price selector
Say the product page shows the price in large text near the "Add to cart" button. Right-click the price and choose Inspect. The developer tools highlight a line such as <span class="price-current">$129.00</span>. The class is price-current, so the selector is .price-current.
Check that it's unique: in the Console, run document.querySelectorAll(".price-current").length. If it returns 1, you're done. If it returns more — for example because recommended products below use the same class — click the highlighted line's parent in the Elements panel and look for an id or a more specific class, such as #product-main .price-current.
For stock status, repeat the process on the "Out of stock" or "In stock" label, then enter both selectors in the monitor separated by a comma: .price-current, .stock-status.
Tips for getting deals in time
Name each monitor after the product and the shop so the alert email tells you at a glance whether to act. Keep the alert email address one you read on your phone. For limited restocks, a faster interval on just that one product page is usually worth more than fast checks on everything.
When an alert arrives, check the shop page directly before buying — prices can change again quickly, and the dashboard's AI summary is a quick way to confirm what moved.
Frequently asked questions
Is Site Monitor free?
Yes. The Free plan covers 10 URLs checked every hour, with 2 AI change summaries a month — no credit card required. Upgrade only if you need faster checks, more URLs, or more AI summaries.
Does it work on pages that load content with JavaScript?
Yes. Site Monitor can render the page in a headless browser before fingerprinting it, so content injected by JavaScript is included in the comparison.
Will rotating ads, timestamps, or counters cause false alerts?
Not if you scope the watch. Add a CSS selector (for example #pricing or .event-list) and Site Monitor fingerprints only that element — everything else on the page is ignored. Whitespace-only changes never trigger an alert.
Can it watch pages behind a login?
No. Site Monitor fetches public URLs the same way a browser would. Pages that require a login, CAPTCHA, or paywall can't be read.
How often does Site Monitor check a page?
Free checks every hour. Paid plans check as often as every 5 minutes, and you can set the interval per URL.
Start watching your first page
Start watching free → Explore the live demo
Free plan · 10 URLs · hourly checks · 2 AI summaries/mo · no credit card