Obstruction · European Union
Comparison prevention
The label “Comparison prevention” describes this recurring design mechanism: information needed to compare products, plans or consequences is presented in inconsistent, fragmented or unusable form. It is a design and research taxonomy, not a standalone legal conclusion. Depending on the complete journey and likely effect, current EU consumer or sector rules may require separate assessment. No published Digital Fairness Act proposal currently creates a pattern-specific prohibition or duty under this label.
- Family
- Obstruction
- Also known as
- Journey stages
Definition
What is this pattern?
Information needed to compare products, plans or consequences is presented in inconsistent, fragmented or unusable form. The label describes a recurring design mechanism; whether a particular implementation is harmful or unlawful depends on the complete journey, audience, evidence and rules within scope.
How it works
Information needed to compare products, plans or consequences is presented in inconsistent, fragmented or unusable form. Material attributes use incompatible units, labels, ordering or one-at-a-time views, forcing avoidable transformation and memory work before alternatives can be compared.
Warning signs
- Two or more realistic alternatives are presented.
- At least one material attribute cannot be compared without avoidable transformation or navigation.
- The structure favours a particular option, default or abandonment of comparison.
Potential harms
- Customers cannot make a meaningful like-for-like comparison and may select a plan with a higher real cost.
- A shopper may be unable to compare material dimensions and may default to the plan the interface opens last.
Learn by comparison
What does this look like?
These fictional examples make the design mechanism easier to recognise. They do not depict a real company and do not establish that an individual interface is unlawful.
Illustrative example 1 · Telecom comparison
A fictional provider shows one plan per week, another per four weeks and a third per gigabyte, without a consistent total or usage assumption.
Potential consumer harm: Customers cannot make a meaningful like-for-like comparison and may select a plan with a higher real cost.
Illustrative example 2 · Insurance quote comparison
A fictional quote tool reveals one plan at a time, clears the previous plan whenever another is opened and provides no stable summary of limits, excess or exclusions.
Potential consumer harm: A shopper may be unable to compare material dimensions and may default to the plan the interface opens last.
Plans use incompatible pricing units
A fictional provider shows one plan per week, another per four weeks and a third per gigabyte, without a consistent total or usage assumption.
Three ways to save. Prices use weekly, four-week and usage units with no common baseline.. Displayed amount: €8: From €8. Open comparison table
Compare monthly cost. Every plan shows the same monthly basis, data allowance, term and total.. Open comparison table. From €8. Price, period and commitment, expanded: The price and material terms associated with “Open comparison table” remain beside this choice.
Why the first version can mislead: The route adds avoidable effort between the user’s stated intention and completion. In this telecom comparison example, the obstacle is: “Prices use weekly, four-week and usage units with no common baseline.” Evidence should show whether the alternative remains usable and whether “Open comparison table” reaches the represented state. Customers cannot make a meaningful like-for-like comparison and may select a plan with a higher real cost.
What a fairer design does: Add a consistent billing-period total, usage basis and sortable comparison while preserving original terms.
Show annotated differences (2)
- Open comparison tableIn “Plans use incompatible pricing units”, this element shows how comparison prevention can shape the decision.
- Price, period and commitment, expanded: The price and material terms associated with “Open comparison table” remain beside this choice.In “Plans use incompatible pricing units”, this element keeps the clearer alternative visible at the same decision point.
Review questions (3)
- How many steps, waits and channel changes separate “From €8” from the completed telecom comparison outcome?
- Place the compared prices, billing periods and material terms on one evidence sheet; where does it support “Two or more realistic alternatives are presented”?
- Measure the same task through the clearest available route: does the effort difference persist once “Inherent differences that cannot be expressed on a shared basis” is accounted for?
Plan details cannot be retained side by side
A fictional quote tool reveals one plan at a time, clears the previous plan whenever another is opened and provides no stable summary of limits, excess or exclusions.
Review one plan. Opening another quote removes the earlier plan and changes the order of attributes.. Open next quote. Open comparison table
Compare three quotes. Selected plans remain visible in one consistent table.. Open comparison table. Open next quote. Price, period and commitment, expanded: The price and material terms associated with “Open comparison table” remain beside this choice.
Why the first version can mislead: The route adds avoidable effort between the user’s stated intention and completion. In this insurance quote comparison example, the obstacle is: “Opening another quote removes the earlier plan and changes the order of attributes.” Evidence should show whether the alternative remains usable and whether “Open comparison table” reaches the represented state. A shopper may be unable to compare material dimensions and may default to the plan the interface opens last.
What a fairer design does: Provide a durable side-by-side table with consistent price, limit, excess and exclusion fields, while keeping source detail available.
Show annotated differences (2)
- Open comparison tableIn “Plan details cannot be retained side by side”, this element shows how comparison prevention can shape the decision.
- Price, period and commitment, expanded: The price and material terms associated with “Open comparison table” remain beside this choice.In “Plan details cannot be retained side by side”, this element keeps the clearer alternative visible at the same decision point.
Review questions (3)
- How many steps, waits and channel changes separate “Open next quote” from the completed insurance quote comparison outcome?
- Place the compared prices, billing periods and material terms on one evidence sheet; where does it support “At least one material attribute cannot be compared without avoidable transformation or navigation”?
- Measure the same task through the clearest available route: does the effort difference persist once “optional advanced detail with a complete comparable summary” is accounted for?
What is a fairer alternative?
Use consistent units, terminology and side-by-side material totals with accessible supporting detail.
Legal and information status
Legal position at a glance
Information needed to compare products, plans or consequences is presented in inconsistent, fragmented or unusable form. Material attributes use incompatible units, labels, ordering or one-at-a-time views, forcing avoidable transformation and memory work before alternatives can be compared. Risk increases where the mechanism changes a material consumer choice, hides a consequence or makes a genuine alternative harder to use. The taxonomy label remains a review prompt and does not establish an infringement.
Dark-pattern research taxonomy
Editorial analysis
The cited research sources support identification and comparison of this recurring interface mechanism. They do not determine that a particular interface is unlawful.
UCPD Articles 5 to 9, where applicable
Possible risk indicator
Depending on the trader, audience, overall presentation, material information and likely transactional effect, the facts may require a separate assessment under the applicable UCPD provisions.
Evidence layers and open questions
Applicable law, enforcement records, policy preparation, stakeholder input, editorial analysis and unknown future details remain visibly distinct.
Current lawCurrent law
The UX label “Comparison prevention” is not a standalone EU offence. Depending on the trader, audience, complete presentation, omitted information and likely transactional effect, the observed facts may require a separate assessment under the applicable UCPD provisions or another instrument within scope.
Under considerationUnder consideration
The Commission is preparing a Digital Fairness Act initiative, but the call for evidence does not select a final rule for comparison prevention or establish that this taxonomy term will appear in a proposal.
Editorial analysisEditorial analysis
The pattern definition, variants and examples on this page use the cited research taxonomy sources to support recognition and comparison. That analytical classification is not a legal conclusion about an individual interface.
UnknownUnknown
No published DFA proposal currently establishes a definition, covered actor, legal threshold, duty, remedy, transition rule or application date for comparison prevention. Those details remain unknown pending primary legislative text.
Context matters
Context and boundary cases
- Two or more realistic alternatives are presented.
- At least one material attribute cannot be compared without avoidable transformation or navigation.
- The structure favours a particular option, default or abandonment of comparison.
- Exclude or qualify the label where inherent differences that cannot be expressed on a shared basis.
- Exclude or qualify the label where optional advanced detail with a complete comparable summary.
- Exclude or qualify the label where minor cosmetic inconsistency.
When a similar design can serve a legitimate purpose
- A similar design should not be classified this way where inherent differences that cannot be expressed on a shared basis.
- A similar design should not be classified this way where optional advanced detail with a complete comparable summary.
- A similar design should not be classified this way where minor cosmetic inconsistency.
Operational review
What teams should review
- Teams
- How many steps, waits and channel changes separate “From €8” from the completed telecom comparison outcome?
- Place the compared prices, billing periods and material terms on one evidence sheet; where does it support “Two or more realistic alternatives are presented”?
- Measure the same task through the clearest available route: does the effort difference persist once “Inherent differences that cannot be expressed on a shared basis” is accounted for?
- How many steps, waits and channel changes separate “Open next quote” from the completed insurance quote comparison outcome?
- Place the compared prices, billing periods and material terms on one evidence sheet; where does it support “At least one material attribute cannot be compared without avoidable transformation or navigation”?
- Measure the same task through the clearest available route: does the effort difference persist once “optional advanced detail with a complete comparable summary” is accounted for?
- Which complete journey evidence supports or contradicts the comparison prevention classification?
Evidence to retain
- Versioned captures of the Pricing states before, during and after the relevant decision
- Configuration, content and event records supporting the observed comparison prevention mechanism
- Responsive, keyboard and assistive-technology review of every material option and consequence
- Price-component, offer-version and calculation records linked to the captured screen
Legal map and implementation tools
Evidence base
Sources
- Dark commercial patternsOrganisation for Economic Co-operation and Development · Secondary · checked 2026-09-14 · OECD Digital Economy Papers No. 336
- Unfair Commercial Practices DirectiveEuropean Parliament and Council of the European Union · Primary · checked 2026-08-09 · Directive 2005/29/EC; CELEX 02005L0029-20220528
- Digital Fairness Act: call for evidence for an impact assessmentEuropean Commission · Primary · checked 2026-08-09 · Initiative 14622; Ares(2025)6275573
- Commission work programme 2026: Europe's Independence MomentEuropean Commission · Primary · checked 2026-09-14 · COM(2025) 870 final; CELEX 52025DC0870; Annex I item 30