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Hick's Law

The more choices you give someone, the longer it takes them to decide — and the more likely they are to give up entirely.

5 min readUX · Product · UI

Think about the last time you typed something into Google before AI Overviews existed. You'd land on a results page with ten blue links. You'd scan titles, try to guess which would answer your question, click one, realise it wasn't quite right, hit back, try another. Thirty seconds for a question with a one-sentence answer.

That friction is exactly what Hick's Law predicts. Decision time grows with the number of choices — and ten roughly-equal options is one of the most expensive decision scenarios a user can face. The arrival of AI summaries in search isn't just a feature change. It's a fundamental reduction in choice load applied at scale, to billions of queries a day.

✦ Key takeaways
✓
Every extra option costs attention. Adding choices taxes the brain for every option it has to read, compare and dismiss — including the ones users never pick.
✓
Fewer choices converts better. Reducing options at a critical moment almost always increases completion rate.
✓
AI is the most powerful application of this law right now. Collapsing ten results into one synthesised answer is Hick's Law at its most dramatic.

Where it comes from

In 1952, psychologists Hick and Hyman gave participants a row of lights, each paired with a button. They varied how many pairs there were and measured response times. Results were clean: decision time grew logarithmically as choices increased. The first few extra options had by far the biggest impact.

T = b × log₂ (n + 1)
T is decision time.
n is the number of choices.
b varies based on task complexity.

The curve rises steeply early, then flattens — the early options are the expensive ones.

Cutting from ten options to five has more impact than cutting from fifty to forty-five. This is why removing a single nav tab, pre-selecting a payment method, or collapsing search results into one answer all have disproportionate effects on how fast users move.

Decision time grows with the number of options
The biggest gains come from removing the first few options
0.5s1s1.5s13581216+Number of choices
“Ten blue links was never a good design. It was just the only option we had. AI finally fixed it.”

How AI search applies this law

For decades, Google's answer to every query was the same: here are ten links, you decide. The AI Overview changes that completely. Instead of ten roughly-equal options demanding evaluation, you get one synthesised answer at the top. Decision time drops to near zero.

Same query, same information — but one puts the work on you, and one doesn't.

Before — 10 links to evaluate
google.com/search?q=hicks+law+ux
Google
what is hick's law ux
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About 2,140,000 results (0.34 sec)
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nngroup.com
https://nngroup.com › ux › hicks-law
Hick’s Law: Making the choice easier for users
Hick's Law predicts that the time to make a decision increases with the number and complexity of choices available.
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lawsofux.com
https://lawsofux.com › ux › hicks-law
Hick’s Law | Laws of UX
The time it takes to make a decision increases with the number and complexity of choices available.
S
smashingmagazine.com
https://smashingmagazine.com › ux › hicks-law
Applying Hick’s Law to UX Design
Learn how designers apply Hick's Law to simplify interfaces and reduce decision fatigue in digital products.
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interaction-design.org
https://interaction-design.org › ux › hicks-law
Hick’s Law: The Complete Guide — IDF
Response time increases logarithmically with the number of stimuli. Named after William Edmund Hick.
W
en.wikipedia.org
https://en.wikipedia.org › ux › hicks-law
Hick’s law — Wikipedia
Hick's law describes the time it takes for a person to make a decision as a function of possible choices.

Six results, all plausible. You have to click each to find the answer.

After — AI answers directly
google.com/search?q=hicks+law+ux
Google
what is hick's law ux
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✦
AI Overview
Hick's Law (also Hick-Hyman Law) states that the time required to make a decision increases logarithmically with the number of available choices. Formulated by psychologists William Hick and Ray Hyman in 1952, it is one of the most widely applied principles in UX design.
T = b × log₂(n + 1)
N
nngroup.com
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lawsofux.com
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wikipedia.org
Web results
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nngroup.com
Hick’s Law: Making choice easier for users
Deep research on reducing decision fatigue...
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lawsofux.com
Hick’s Law | Laws of UX
Visual guide with interactive examples...

Answer synthesised at the top. Sources available if you need depth.

The second screen hasn't removed the links — it's moved them below a direct answer. Users who need the source can still find it. Users who just want the answer don't have to choose between six roughly-equal options to get it.


The same shift is happening inside apps

It's not just search. The same problem existed in every powerful tool with a complex interface — advanced query builders, filter systems, settings panels with dozens of toggles. Natural language AI interfaces collapse that load to one: a blank input and a cursor.

Before — Complex query builder
9:41
FiltersReset
Statusis any ofIn Progress, Review
AssigneeisMe
Priorityis notLow
LabelincludesDesign
Sort by
UpdatedDescending
Group byStatus
Date range
Apr 1toApr 7

Full control — but enormous cognitive cost before seeing a single result.

After — One search input
9:41
Search
In ProgressDesignAssigned to me
Results · 4
Redesign checkout flow
In Progress · Today
Nav refactor — mobile
In Progress · Yesterday
Empty-state illustrations
Review · Apr 8
Pricing page A/B
In Progress · Apr 6

Type what you need. The system figures out the filters.

The query builder isn't broken — for power users who need precise control, it's the right tool. But for everyone else, the AI interface gets to the answer faster because it's removed every intermediate decision.


Where it still matters in traditional UI

Even without AI, Hick's Law determines whether someone completes a checkout. Payment screens are one of the clearest test cases. A user who has already decided to buy something just needs to pay. Every extra choice is pure friction.

Before — 7 payment methods
9:41
Payment$84.00
Choose payment method
Apple Pay
Express checkout
VISA
Visa
•••• 4242
P
PayPal
john@email.com
K
Klarna
Pay in 4 instalments
A
Afterpay
Pay in 4, interest-free
₿
Bitcoin
Crypto payment
Bank transfer
ACH or wire
Secured by 256-bit encryption

Which is fastest? Does Klarna affect credit? What fees does PayPal charge?

After — 1 primary + overflow
9:41
Payment$84.00
Order summary
Subtotal$72.00
Shipping$12.00
Total$84.00
or

Visa, PayPal, Klarna and 4 more under
“Pay another way”

Secured by 256-bit encryption

Fastest method pre-selected. Other options are one tap away if needed.

The second checkout doesn't remove payment options — it pre-selects the fastest and most secure one available on the device and moves the rest behind a single overflow.


One input, deep answers

When the interface collapses to a single input, the surface area for Hick's Law goes to zero. No toggles to choose between, no filters to configure — just a question and a synthesised answer with sources.

Deep research
9:41
Research
Pro
summarise hick's law research since 2020 with evidence
✦
AI
Summary (2020–2025):
Recent studies broadly confirm Hick's original logarithmic curve, with three qualifiers:

1. Familiar options are cheaper — users parse known brands faster than novel labels.
2. Visual grouping reduces effective n — 20 items in 4 groups behaves closer to 4.
3. AI-mediated interfaces collapse n to 1 for most intents, shifting the bottleneck to trust.

Pulled from 14 peer-reviewed papers and 6 industry reports.
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A single prompt replaces filters, tabs, and source evaluation.


Applying this to your work

Hick's Law shows up everywhere — navigation bars, onboarding forms, pricing pages, filter systems. The most important shift happening in product design right now is AI reducing option counts at the system level — converting ten results into one answer, a twelve-field form into a single prompt.

✓ Apply it like this
→Pre-select the recommended option wherever comparison is required — payment, plan selection, notification defaults.
→Limit primary navigation to 4 items and move everything else behind an overflow or profile menu.
→Ask one onboarding question per screen — the total can be the same, the felt effort is completely different.
→Use AI to collapse complex configuration into natural language wherever the task allows it.
✗ Common mistakes
→Showing all payment methods, plan tiers, or filters simultaneously without a clear recommended path.
→Adding nav tabs because a feature is important. Importance doesn’t mean permanent visibility.
→Confusing more options with more control. Control comes from clarity, not from volume.
→Adding AI as decoration — a chatbot on a cluttered interface doesn’t reduce its Hick’s Law cost.

Hick, W. E. (1952). On the rate of gain of information. Quarterly Journal of Experimental Psychology. · Hyman, R. (1953). Stimulus information as a determinant of reaction time. Journal of Experimental Psychology.