Chook Check 作者： Nevenit

Chook Check tracks the prices you actually see on Woolworths and Coles, builds a private price history just for you, and — only if you choose to opt in — pools
observations across users so everyone can spot when a "special" isn't really special.

Australian supermarkets increasingly use personalised pricing, loyalty-tier promotions, and rotating "specials" that aren't always cheaper than the regular price.
The same product can cost different amounts depending on who's looking, what account they're logged into, or what state they're in. Chook Check makes this
visible.

What it does

Whenever you visit a product page on woolworths.com.au or coles.com.au, Chook Check passively records the price you see. Over time you build up a personal history
showing how that product's price has moved — useful for noticing when a "1/2 PRICE!" offer is actually the most common price for that product over the last 60
days.

A small green pill appears next to the price on each product page. Click it to see your price history sparkline, the lowest and highest prices you've seen, and
(when enough community data exists) what other people are paying.

The dashboard, accessed from the popup, gives you the full picture: chart-based price history per product, a searchable table of every product you've tracked, and
an export-to-JSON button for everything.

Privacy by default

The default behaviour is local-only: every observation lives in your browser's IndexedDB and goes nowhere. There's no account, no signup, and no data leaves your
machine.

If you'd like to contribute to the community dataset, you can opt in from Settings. Even when you opt in, you choose exactly what optional context to share
alongside the price data:

• Browser (default on, near-zero privacy cost)
• State (off by default — VIC/NSW/etc.)
• City (off by default)
• Specific store (off by default)

You enter your state, city, and store manually — Chook Check never tries to detect them automatically. You can change any toggle at any time, and changes apply
only to future observations. A consent log records every change you make.

What we never collect

• Real name, email address, password, or any login credential
• Loyalty card numbers (Everyday Rewards, Flybuys)
• IP address (the API never logs it against observations)
• Browsing history outside Woolworths/Coles product pages
• Cart contents, order history, or anything from your supermarket account
• Any data from non-Woolworths, non-Coles websites

The extension declares only two host permissions: woolworths.com.au and coles.com.au. The browser will physically prevent it from accessing any other site.

Sale highlighting

The dashboard chart and the in-page sparkline both highlight sale-price observations in amber, so you can see at a glance which prices were promotions versus the
everyday price. Hover any amber point to see the promo type (e.g. "half_price", "member_price", "special").

Community insights (when contributing)

Once at least 3 different contributors have observed a product, the in-page panel shows the community median price, the spread, and how often that product appears
at each promo type. Stats stay hidden below the 3-contributor threshold to prevent any single user from defining a product's "community price".

Open source on both ends

The extension is open source under MIT at https://github.com/Nevenit/Chook-Check

The community API is open source under AGPL-3.0 at https://github.com/Nevenit/chook-check-api — anyone running a modified version of the service is required to
publish their source.

Read the full privacy policy: https://github.com/Nevenit/Chook-Check/blob/main/PRIVACY.md

Why "Chook Check"?

"Just doing a quick chook check before heading to Woolies." It's the supermarket equivalent of a quick weather check — a five-second sanity test before you spend
money.