ShopHop · Methodology · Last updated 7 June 2026

How we do it

ShopHop tracks every advertised price at Woolworths, Coles and Aldi and keeps it current. This page documents how we detect misleading “specials,” how we cross-reference products across retailers, and how anyone can verify our findings.

Data collection

We capture the publicly visible product listings at Woolworths, Coles and Aldi on an ongoing basis. Each capture records the advertised price, any “special” or “was” price, the unit price, pack size, and category. Snapshots are timestamped and stored permanently — we never overwrite historical records.

Coverage as of 7 June 2026: 555,000+ products across three retailers, with over 1.2 million price snapshots in our archive.

What we capture per product
  • Advertised price and any “was” / regular price
  • Sale flag (whether the retailer marks it as a special)
  • Unit price and pack size
  • Brand, category, and product name exactly as shown online
  • Timestamp in AEST

Cross-store matching

When the same product is sold at multiple retailers, we link the listings to a single canonical product. This powers our “where to buy” comparisons and cross-store price records.

A pair of products is considered the same if they match on all of:

  • Brand (exact match after normalisation)
  • Size (within 5% after unit normalisation — 500g ≠ 600g)
  • Pack count (a 5-pack is never the same as a single)
  • Variant or flavour (Original ≠ Sour Cream & Chives)
  • Form (liquid ≠ powder, fresh ≠ frozen)

We use a two-stage approach. First, a fast trigram-similarity pre-filter eliminates obviously unrelated products. Then Claude Haiku evaluates the remaining candidates using the matching rules above. High-confidence matches are auto-confirmed. Medium-confidence pairs go to manual review.

Every mapping is logged with its source (algorithmic, AI-assisted, or human-confirmed), confidence score, and timestamp. As of 7 June 2026, we have confirmed 500+ cross-store product matches.

How we flag fake specials

The Federal Court found in May 2026 that Coles made misleading representations about 245 Down Down promotions — prices were temporarily raised before promotions so the “discounted” price was the same as or higher than the original. ShopHop flags this pattern automatically.

A “special” is flagged as potentially misleading if any of these conditions hold:

1
Price above median
The "special" price is at or above the product's 90-day median price. You'd typically pay less without the sale.
2
Artificial peak then drop
The price was raised by more than 15% in the past 30 days, then "dropped" to a value still above the prior 90-day median.
3
Recently cheaper
The same product had a lower "special" price within the last 60 days.

Every flagged special is individually validated against the full 90-day price history. Flags that could be explained by legitimate cost movements are marked for human review rather than published. Public explainers cite specific dates and prices — we do not editorialise.

Fake-special detection requires 90 days of price history to be statistically reliable. Our full detection activated in mid-2026.

How to verify our findings

Every product page on ShopHop shows the full 90-day price history as a chart. The dates and prices we cite in explainers are always verifiable from the chart on the product page — click any flagged special to see the underlying data.

Our scraping timestamps, price values, and sale flags are stored verbatim from the retailer's own product pages. We don't infer or adjust prices.

Limitations

We track online advertised prices, not in-store prices. These can differ. We don't capture loyalty pricing (Everyday Rewards, Flybuys), member-only discounts, or bulk-buy deals unless they are publicly advertised on the product page.

Our cross-store matching is high-accuracy but not perfect. Mappings flagged as uncertain are excluded from automatic comparisons until human-verified. If you spot an incorrect match, email us.

Prices are kept current. In-store prices may vary and are not verified by ShopHop.

For media and researchers

ShopHop is independent. We accept no payment from any retailer, brand, or industry body. All data presented on this site is derived from publicly available product listings.

Journalists, researchers, and government bodies can request the raw underlying snapshot data for analysis.

Media enquiries: [email protected]Data requests: [email protected]

Prices shown are sourced from publicly visible online listings and may not reflect current in-store prices. Data is refreshed regularly. Learn more

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