Short answer: dark patterns in online stores are interface designs meant to push you into a purchase or consent you didn’t intend to give: fake timers, “only 2 left” messages, hidden costs, pre-checked add-ons, or difficult cancellation. The key rules of defense are: don’t decide under time pressure, check the final price in the cart, uncheck everything that was checked for you, and read what exactly a button does. Below we describe the 8 main tricks, 20 concrete examples, and ways to spot them, as well as what to do if you’ve already fallen for one.
What dark patterns are and why stores use them
Dark patterns (also called deceptive patterns in the literature) are elements of a website or app interface designed to steer the user’s decisions against their interest. They don’t work through outright bans or lies, but through page layout, colors, wording, and psychological pressure. Stores use them because they work at scale: changing the look of a button or adding a counter is enough to increase sales.
It’s worth noting that not every message about limited availability is manipulation. Stock really does run out. The problem arises when the message is false, artificially repeated, or impossible to verify.
How often stores use dark patterns: the data
| Source | Result |
|---|---|
| Sweep by the European Commission and national authorities (CPC network, 23 EU countries, Norway, and Iceland) | Manipulative practices in 148 of 399 stores checked (about 37%): including fake timers, hiding information, and steering choices |
| Study by Princeton University and the University of Chicago (about 11,000 stores, 53,000 product pages) | 1,818 instances of dark patterns in 15 types and 7 categories; 22 companies selling ready-made plugins with such patterns were identified |
| UOKiK, actions in Poland | Charges against born2be.pl and renee.pl for timers that restarted the countdown after time ran out; a fine of over PLN 5.3 million for Vinted (not final, the company appealed); proceedings against OLX |
8 store tricks: how they work and how to spot them
Fake timer: a countdown that never ends
A clock counts down the minutes to the end of a promotion, but after time runs out it goes back to the beginning or the offer continues. UOKiK accused the stores born2be.pl and renee.pl of such practices: after time ran out, the clock started counting down to the next promotion, and permanent offers were presented as deals, e.g., under the name “crazy Wednesday.”
How to spot it: refresh the page, open it in a private window, or come back the next day. If the counter has started over, it’s not a real deadline.
“Only 2 left”: artificial scarcity
A message about a small number of items increases the sense of loss and prompts a quick decision. It can be true, but it can also be a permanent fixture of the product page.
How to spot it: check the same product at another time and in another store, and see whether “2 left” appears for every size. Add it to the cart and check whether the system doesn’t let you select a larger quantity.
Fake discount: a crossed-out regular price
A crossed-out higher price suggests a bargain. Regulations require that when announcing a discount, the store state the lowest price from the 30 days before the discount, in a legible and clear way.
How to spot it: find the information about the lowest price in the last 30 days. If it’s missing or hidden in small print, treat the “sale” with caution and check the price on a comparison site.
Hidden costs: the price goes up at the end
A low price on the product list, and only at the last step do service fees, insurance, or handling costs appear. UOKiK challenged, for example, Vinted’s “Buyer Protection” fee, which was added only at the end of the order.
How to spot it: go through the cart to the last step (without clicking “Pay”) and compare the total with the list price. On platforms with fees, check whether sorting “from cheapest” takes additional fees into account.
Pre-checked add-ons
Insurance, an extended warranty, a newsletter, or a paid service added through a box checked in advance. According to the Polish Ministry of Finance’s guide, consent to an additional payment must be explicit and cannot result from a default option.
How to spot it: before buying, review every checkbox and the list of items in the cart. If something was added without your click, uncheck it or demand a refund.
Confirmshaming: a button that shames you
The decline option is worded to make you feel guilty or foolish, e.g., “No, I prefer to pay more.” Wikipedia defines confirmshaming as inducing guilt through the wording of the decline option.
How to spot it: compare the “yes” and “no” buttons. If one is big and colorful and the other is a gray link with emotional text, that’s pressure.
Subscription trap: easy to get in, hard to get out
A trial period turns into a paid subscription, and cancellation requires several steps or contacting customer service. This is the so-called “roach motel.” The US FTC pursued a high-profile case concerning Amazon Prime, which ended in a $2.5 billion settlement in 2025.
How to spot it: before signing up, check how to cancel and when the trial period expires. Set a calendar reminder before the free period ends.
Fake social proof: “Bestseller” and “5 people are viewing”
Labels such as “Bestseller,” “Customers’ choice,” or a counter of people viewing an offer are meant to show popularity, but they aren’t always based on data. Materials about UOKiK’s AI system for detecting dark patterns explicitly mention “bestseller labels creating fake social proof.”
How to spot it: check whether the label has a clear criterion (e.g., “most purchased in the last month”). Look at the content of reviews, not just the number of stars.
20 examples of how stores try to rip us off
The table below collects 20 patterns you may come across. Some are based on specific UOKiK cases (born2be.pl, renee.pl, Vinted, OLX), and the rest are typical practices described in the dark patterns literature. Remember that the message itself isn’t proof of manipulation; only its falsity or lack of basis is.
| # | Pattern | What it looks like | How to spot it or what to do |
|---|---|---|---|
| 1 | A timer that resets | A clock counts down to the end of a promotion, and after zero it starts over (UOKiK’s charge against born2be.pl and renee.pl) | Refresh the page or open it in a private window |
| 2 | A cart timer: “we’re reserving it for 10 minutes” | A countdown of the reservation time for products in the cart | If the time runs out, see whether the product really disappears from the cart |
| 3 | “Only 2 left” | Low stock shown next to the product | Check in another store and at another time; try adding more items |
| 4 | “5 people are viewing this product” | A counter of supposedly active shoppers | See whether the number changes sensibly; treat it as an ad |
| 5 | “120 sold in the last 24 hours” | Sales data without a stated method | Look for the source of the number; no source is a warning sign |
| 6 | A crossed-out “regular price” | A higher price suggesting a discount | Look for the lowest price from the 30 days before the discount |
| 7 | A sale that never ends | Permanent offers presented as deals, e.g., “crazy Wednesday” | Note the price today and check it in a week |
| 8 | Shipping cost at the last step | A list price without shipping costs | Go through to the end of the cart before deciding |
| 9 | A service fee added at the end | E.g., a buyer protection fee shown only at checkout (the Vinted case) | Compare the final total with the list price |
| 10 | Sorting “from cheapest” without fees | The ranking omits additional fees (UOKiK’s charge against OLX) | Compare totals in the cart, not the order of the list |
| 11 | Pre-checked insurance or warranty | A paid service added by the site’s click, not yours | Review all the boxes; demand a refund if it was added without consent |
| 12 | A free trial that turns into a paid plan | Card entered at the start, charge after the period ends | Set a reminder before the period ends |
| 13 | Difficult subscription cancellation | Signing up is one click, canceling is many steps or contacting support | Check the cancellation rules before signing up |
| 14 | A button without payment information | E.g., “Next” instead of “Order with obligation to pay” | The button must clearly refer to payment; without that, the contract may not be concluded |
| 15 | Confirmshaming | “No, I don’t want to save” as the decline button | Look for a neutral decline option; don’t let yourself be shamed |
| 16 | A trap button | A big, colorful consent button and a tiny gray decline link | Pay attention to what is less visible |
| 17 | Making it hard to reject consents (cookies, marketing) | Consent in one click, refusal after many steps | Choose the option to decline or manage consents; consent must be unambiguous and voluntary |
| 18 | A “Bestseller” or “Customers’ choice” label | Badges without a disclosed criterion | Look for a description of the criterion; read reviews, not badges |
| 19 | Fake or too-perfect reviews | Only five stars, boilerplate sentences | See our guide on reviews and check the dates and details |
| 20 | Bait and switch | The advertised cheap product is unavailable, and the store offers a more expensive one | Check availability before buying; don’t change your decision under pressure |
How to spot dark patterns: 10 practical tests
- 1. The refresh test. Refresh the page or open it in a private window. A timer that starts over is a dummy.
- 2. The next-day test. Come back to the offer a day later. The same “last chance” indicates a permanent price.
- 3. The full-cart test. Go to the last step without paying and compare the total with the list price.
- 4. The checkbox test. Read every checked box and every item in the cart. Uncheck what you don’t want.
- 5. The button test. Read what the order-completion button says. It must clearly state the obligation to pay.
- 6. The 30-day price test. With a discount, look for information about the lowest price in the last 30 days. Take a screenshot of the price and check it later.
- 7. The comparison test. Check the same product in another store or on a price comparison site.
- 8. The 24-hour test. Postpone the purchase if it isn’t urgent. A real bargain usually survives a day, and time pressure is one of the main signs of manipulation.
- 9. The cancellation test. Before creating an account or a subscription, check how to unsubscribe. If you can’t find it, that’s a warning.
- 10. The emotion test. If you feel pressure, fear of missing out, or shame, stop. It’s a sign the interface is playing on your emotions.
What the law says about dark patterns in Poland and the EU
- Price reductions (Omnibus). Information about the lowest price in the 30 days before a discount must be legible and clearly described. For violations, the Trade Inspection can impose a fine of up to PLN 20,000 (up to PLN 40,000 for three violations in a year), and the President of UOKiK up to 10% of the company’s turnover and up to PLN 2 million for a manager.
- The order button. The button completing a purchase must be labeled with the words “order with obligation to pay” or equivalent, and if this requirement isn’t met, the consumer is not bound by the contract.
- Pre-checked add-ons. According to the Ministry of Finance’s guide, consent to an additional payment cannot result from a default option, and the consumer may demand a refund.
- Withdrawal from the contract. For distance purchases, you have 14 calendar days to withdraw without giving a reason, and if the seller didn’t inform you of this right, the period is extended to 12 months.
- Unfair commercial practices. Manipulative patterns may be considered practices that mislead consumers, for which UOKiK can impose a fine of up to 10% of turnover.
- DSA. The EU Digital Services Act explicitly prohibits dark patterns on online platforms, and the ban has applied in full since February 17, 2024.
This article is not legal advice. In a specific case, get help from a consumer ombudsman or a lawyer.
What to do if you’ve already been fooled
Secure the evidence
Take screenshots of the page, the cart, the order confirmation, and the terms. Note the date and the page address.
Use your right of withdrawal
Within 14 days of receiving the goods, you can withdraw from a distance purchase contract without giving a reason, with a few exceptions (e.g., custom-made goods, unsealed hygiene products).
Demand a refund of unwanted fees
If a paid service was added through a pre-checked box, write to the store and demand a refund of the amount, citing the lack of explicit consent.
Report the practice
Notify UOKiK or the Trade Inspection, and in an individual case contact your district (municipal) consumer ombudsman. Attach the evidence.
Secure your payment
If the seller doesn’t respond, consider contacting your bank about the card transaction dispute (chargeback) procedure. Details depend on your bank.
FAQ: the most common questions about dark patterns in stores
They are elements of a website or app interface designed to push the user toward a decision they wouldn’t make consciously, e.g., a purchase, consent, or subscription. They are also called deceptive patterns.
No. Real promotions have deadlines. The problem arises when the counter resets after time runs out or the offer continues. UOKiK brought such charges against the stores born2be.pl and renee.pl. Refresh the page or come back the next day to check.
Sometimes it is, but it’s a common pressure technique. Check the same product at another time and in another store, and for big purchases try adding more items to the cart.
With a discount, the store should state the lowest price from the 30 days before the discount. If the information is missing or unclear, compare the price in other stores and note it down to check again after a few days.
No. According to the Ministry of Finance’s guide, consent to an additional payment must be explicit and cannot result from a default option, and the consumer may demand their money back.
The button completing a purchase must clearly state the obligation to pay. If it doesn’t, the consumer is not bound by the contract under the regulations.
Yes, in most cases you have 14 calendar days without giving a reason, and if the seller didn’t inform you of this right, the period is extended to 12 months. There are exceptions, e.g., custom-made goods.
To UOKiK or the Trade Inspection, and in an individual case to a consumer ombudsman. Attach screenshots and the order confirmation.
Yes. Bestseller-type badges without a clear criterion and fake reviews can create fake social proof. See our guide on the reliability of reviews on Google, Allegro, and Booking.
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Sources: European Commission, press release IP/23/418 on the sweep of manipulative practices in online stores (148 of 399 stores); Umweltbundesamt (Germany), description of the store sweep and three types of practices; Mathur et al., “Dark Patterns at Scale: Findings from a Crawl of 11K Shopping Websites”; Bird & Bird, “Dark Patterns becoming a new hot topic for the Polish regulator” (UOKiK actions: Vinted, OLX, born2be.pl, renee.pl); Bezprawnik, on UOKiK’s charges against born2be.pl and renee.pl (March 30, 2023); Wiadomości Handlowe, on UOKiK’s AI system for detecting dark patterns (March 16, 2026, only an excerpt visible); Antyweb, on the rules for presenting price reductions and penalties; Poradnik Przedsiębiorcy, “The ‘Order with obligation to pay’ button”; Ministry of Finance, “Shopping online” (consumer rights); Wikipedia, “Dark pattern” (typology of patterns and regulations). This article is for educational purposes and is not legal advice.