How Price Tracking Actually Works

Step 1: A product gets added

Someone pastes a product link, or PriceTrail's own discovery process finds it on a store's listing pages. Either way, the very first thing that happens is a live check of that page: current price, MRP, stock status, and whatever product details are available. That first check becomes point one on the chart.

Step 2: It gets checked again, and again

From there, the product is re-checked on a recurring schedule — how often depends on how many products are being tracked in total and how much server capacity is available to check them, since re-checking a live web page (not an API) takes real time and real compute per product. A product with an active price alert gets checked more frequently than one nobody's watching, since a missed drop matters more there.

This is also why a price change on a store's own site isn't reflected instantly everywhere that tracks it — there's always some lag between a store changing a price and the next scheduled check catching it, typically hours, occasionally longer for less-frequently-checked products on very large catalogs.

Step 3: Every result gets kept, not just the latest one

The part that actually makes a price history useful is refusing to throw away old data. Every recorded check — price, MRP, stock status, timestamp — is stored permanently, which is what makes it possible to answer "was this cheaper last month" honestly instead of guessing from a single "was ₹X" number a store chooses to show you.

Step 4: The numbers you actually see get computed from that history

The all-time low, the 90-day average, and the Deal Confidence Score aren't manually set by anyone — they're calculated fresh from the full recorded history every time a product's data updates. A product only earns a genuine Lowest badge when its current price has actually, recently reached a new recorded floor — not because it's simply never had a second price check yet, and not because of a drop from months ago that's since gone stale. See our guide on verifying a lowest-price claim for how that plays out on an actual listing.

Why out-of-stock products don't wreck the chart

When a product goes out of stock, some store pages briefly show a stale or unrelated price (from a recommended item, or a cached page). Recording that as a real price point would quietly corrupt the entire history. Instead, an out-of-stock check is recorded as exactly that — no price, no history entry — so a chart's low and high always reflect prices the product genuinely, actually sold at.