Miller's Law
Limit short-term memory load by chunking information and capping options.
Definition
Miller’s Law states that your users can juggle only 7 (±2) items in short-term memory at once, so dumping a wall of options on them is a one-way ticket to confusion.
This principle is rooted in cognitive psychology research from George A. Miller, showing that human working memory has a tight capacity limit. Once you cross that threshold, errors spike and decision time drags.
In UX, you chunk content, break it into bite-sized groups, so people process faster, recall key details, and act without mental overload. It’s fundamental in human–computer interaction because every click, scan, or form field adds cognitive tax.
Respecting Miller’s Law means you trim, group, and sequence information to match real human limits. Do it right, and users stay on task. Overdo it, and they drop off.
Real world example
Think about the Spotify mobile app’s playlist details. Instead of listing every track attribute at once, Spotify groups information into discrete sections, track title, artist, album art, and controls. Your brain processes one chunk at a time, so you can quickly hit play or shuffle without scanning a data dump.
Real world example
Miller’s Law matters anywhere users juggle data. In user onboarding flows, break steps into 5–7 fields rather than one giant form. On crowded pricing pages, group plan features into logical clusters instead of a single bullet list of 15 items. Within complex navigation menus, nest related links under clear headings so users find what they need without counting rows of links.
What are the key benefits?
Everything you need to make smarter growth decisions, without the guesswork or wasted time.
Group related form fields into smaller sections of 5–7 items.
Use progressive disclosure to reveal additional options only when needed.
Label and separate UI elements into meaningful categories.
What are the key benefits?
Everything you need to make smarter growth decisions, without the guesswork or wasted time.
Don’t display long, unsegmented lists, split them into chunks.
Avoid showing more than 7 menu links at once.
Never dump all user settings on one page without grouping.
Frequently asked questions
Growth co-pilot turns your toughest product questions into clear, data-backed recommendations you can act on immediately.
How strict is the 7±2 limit in modern UX?
It’s a guideline, not a hard rule. Depending on context you can push to 9 or trim below 5, but always test to see where your users start struggling.
Can I use Miller’s Law with infinite scroll or search features?
Yes. Use search to let people narrow choices instead of scrolling through 20+ items at once. Then chunk results into pages of 5–7 for quick scanning.
What if my product inherently has more than 9 options?
Segment them into categories, use tabs or filters, and reveal deeper options progressively. Always keep on-screen choices within that sweet spot.
Is Miller’s Law relevant on mobile vs. desktop?
Absolutely. Mobile screens amplify overload, chunking and progressive disclosure are even more critical on small viewports.
How do I measure if I’m violating Miller’s Law?
Use user testing and analytics: track where users pause, bounce, or abandon flows. If decision time spikes past benchmarks, it’s a signal you’ve overloaded working memory.
Cap Cognitive Load Now
Overstuffed pages kill conversions. Run your key flows through the CrackGrowth diagnostic to pinpoint where you’ve busted the 7±2 rule and lose users to overload.