What are dark patterns

The expression describes a relationship between design and decision, not a closed list of components. A large button does not make a page manipulative, and neither does a genuine countdown. What makes a pattern dark is that the interface distributes effort and visibility unevenly across the available options: accepting costs one click while refusing costs three screens, the final price appears once the payment details have already been entered, the box that activates the subscription comes pre-ticked and its explanation lives in a grey footnote.

Three layers are worth keeping apart, because they are often mixed. Legitimate persuasion sets out a real advantage and leaves the decision untouched. Acceptable pressure recalls a deadline that genuinely exists and can be verified. Manipulation alters the perception of context: it invents scarcity, hides the cost, shames whoever says no, or turns cancellation into an administrative maze.

The boundary is not set by the design team's taste. It follows from two verifiable questions. Is the information relevant to the decision available at the moment of deciding, with visual weight comparable to that of the opposite alternative? Can the option that is less profitable for the company be carried out with effort similar to the more profitable one? When either answer is negative, the design is already taking part of the decision instead of the person.

Regulation (EU) 2022/2065, known as the Digital Services Act, prohibits in Article 25 that providers of online platforms design, organise or operate their interfaces in ways that deceive or manipulate the recipients of the service, or that distort or impair their ability to make free and informed decisions. Recital 67 lists the examples the legislator had in mind: giving one option more visual prominence, repeating a request for a choice already made, and making cancellation harder than sign-up. The obligation has applied to all platforms since 17 February 2024.

That article does not cover the whole field. Its paragraph 2 excludes practices already regulated by Directive 2005/29/EC on unfair commercial practices and by the General Data Protection Regulation, so as to avoid two regimes for the same facts. In practice, an invented scarcity notice is judged as a misleading commercial practice, while a cookie banner with a hidden reject button is judged as invalid consent. The European Data Protection Board has published dedicated guidelines on such designs in social media interfaces, adopted on 14 February 2023.

Supervision is active. A coordinated sweep by the consumer protection cooperation network across 399 online shops, published in January 2023, found at least one of the three practices examined in 148 of them: fake countdowns, interfaces that push towards a purchase or a subscription, and hidden information. The Commission has also announced a Digital Fairness Act for the fourth quarter of 2026, so far without a published legislative text.

The decision that depends on this concept is concrete: which variant gets approved and which gets sent back when a test promises to lift a number. Optimisation teams work with variants, and some of them win because the person makes a mistake. That kind of gain carries a deferred cost that does not appear on the experiment dashboard, and that comes back as returns, cancellations, complaints and, in the European Union, exposure to enforcement.

For a company operating across several markets the risk is not evenly spread either. The same sign-up flow can be unremarkable in one jurisdiction and sanctionable in another, and responsibility falls on whoever publishes the interface, not on the agency or the tool that produced it.

There is also a measurement effect. When design induces clicks that do not reflect intent, conversion metrics stop describing real demand and later decisions rest on contaminated data. A funnel that performs very well and a customer base that leaves early are often the same phenomenon seen from two different reports.

• Run a symmetry test before publishing: accepting, refusing, unsubscribing and cancelling must require a comparable number of steps and a comparable visual hierarchy.
• Show the total price, including taxes and shipping, on the first screen where the figure influences the decision, and not after collecting personal data.
• Tie every urgency or stock message to a system value. If the counter does not read a real inventory or a real deadline, remove it.
• Document the consent flow with dated captures and record which version was active in each period, because the burden of proving compliance falls on the controller.
• Add a regret metric to the review of every test: returns, cancellations within the first thirty days, and customer service contacts.
• Submit sign-up, cancellation and automatic renewal flows to legal review before an international rollout, because the assessment depends on the market and on the type of service.

• Confusing clarity with manipulation and hiding useful information out of caution. A real advantage explained precisely is not a dark pattern.
• Copying the flow of a large platform on the assumption that, since it is still online, it has already passed a legal filter.
• Treating the cookie banner as a design matter rather than a matter of documentary evidence, until a request arrives and there is no record of what was shown.
• Declaring a variant the winner because of its immediate effect, without observing how that cohort behaves weeks later.
• Assuming that responsibility passes to the supplier of the template or of the consent management tool.