--- title: "Lean UX" url: "https://insideuxdesign.com/en/glossar/lean-ux" language: "en" description: "What is Lean UX? A plain-language explanation with its foundations, hypotheses, an example and practical tips. Learn how your team can learn faster." published: "2026-10-14T15:20:30+02:00" updated: "2026-10-14T15:20:30+02:00" --- # Lean UX Lean UX is a way of working in which teams turn assumptions into hypotheses and test them with small experiments. Shared learning replaces heavy documentation. - **Buchstabe:** L - **Englischer Begriff:** Lean UX UX glossary · engl. Lean UX # Lean UX Lean UX is a way of working in which teams turn assumptions into hypotheses and test them with small experiments. Shared learning replaces heavy documentation. Imagine a team spends three months on a detailed concept for a new feature: personas, wireframes, a 60-page specification document. After launch, it turns out hardly anyone uses the feature. The assumption behind it was never tested. Lean UX is an alternative to exactly this way of working. ## Explained simply Lean UX is a way of working in which a team turns its assumptions about users and the product into testable hypotheses early on and checks them with small experiments. Instead of handing over long documents, design, development and product management work closely together and learn in short cycles. “Lean” doesn’t mean “cheap” here. It means not putting effort into things that help nobody. Think of cooking for a dinner party. Before you make a new recipe for twenty guests, you’d rather try it out on a small scale first. If it doesn’t taste good, you haven’t lost much and you know what to change. The approach was popularized by Jeff Gothelf and Josh Seiden, mainly through the book “Lean UX,” first published by O’Reilly in 2013. The third edition came out in 2021 and works with the Lean UX Canvas, among other things: a template that helps teams structure the problem, goals, users, solution ideas and hypotheses together on a single page. ## The three foundations Gothelf and Seiden describe three roots. From **UX design** and design thinking comes the focus on the needs of the people who use a product. From **agile software development** come collaboration, working results over extensive documentation and the willingness to change plans. From **Lean Startup** by Eric Ries comes the build, measure, learn loop. A central idea is the focus on **outcomes over outputs**. An output is what a team delivers, such as a feature. An outcome is the change in people’s behavior that results from it, for example more customers completing an order without help. Success is measured by the outcome. Hypotheses often follow a simple pattern, roughly: we believe this solution will lead to this result for these people, and we’ll know we’re right when we see a specific measurable signal. You can read more in [Lean UX: Trend or Real Improvement?](https://insideuxdesign.com/en/blog/lean-ux-trend-or-real-improvement). ## An example Here’s an example: a team suspects that people using a fitness app want an AI-generated training plan. Instead of building the whole feature, they add a “Create my plan” button that initially only leads to a short survey and a waiting list. After two weeks, it’s clear how many people tap the button and what they’re hoping for. Based on that, the team decides whether and how to continue. These kinds of minimal versions are called a [minimum viable product](https://insideuxdesign.com/en/glossar/minimum-viable-product). ## In practice - **Write down your assumptions.** Collect as a team what you only believe about users and the product, then prioritize what’s riskiest. - **Test small and fast.** A clickable [prototype](https://insideuxdesign.com/en/glossar/prototype), a landing page or a conversation is often enough to check a hypothesis. - **Learn together.** Review test results as a whole team instead of passing reports around. The original book is listed under [Lean UX](https://insideuxdesign.com/en/ressourcen/lean-ux), and many methods for small teams are collected in [Lean UX für kleine Teams](https://insideuxdesign.com/en/ressourcen/lean-ux-fuer-kleine-teams) (in German). ## Related terms [Minimum Viable Product](https://insideuxdesign.com/en/glossar/minimum-viable-product), [Prototype](https://insideuxdesign.com/en/glossar/prototype), [User Research](https://insideuxdesign.com/en/glossar/user-research), [A/B Testing](https://insideuxdesign.com/en/glossar/a-b-testing) ## Sources - [Jeff Gothelf, Josh Seiden: Lean UX, 3rd Edition. O’Reilly Media, 2021](https://www.oreilly.com/library/view/lean-ux-3rd/9781098116293/) - [Jeff Gothelf, Josh Seiden: Lean UX: Applying Lean Principles to Improve User Experience. O’Reilly Media, 2013](https://www.oreilly.com/library/view/lean-ux/9781449366834/) - [Josh Seiden, Jeff Gothelf: The 3 foundations of Lean UX. O’Reilly, 2017](https://www.oreilly.com/ideas/the-3-foundations-of-lean-ux) ## More terms [ ### A/B Testing An A/B test is an experiment that shows two versions of a page or element at the same time to randomly split groups of visitors. It lets you decide with real data which version works better. ](https://insideuxdesign.com/en/glossar/a-b-testing) [ ### ARIA ARIA is a W3C standard that adds roles, states and properties to HTML. It tells screen readers what an element is and how it currently behaves. ](https://insideuxdesign.com/en/glossar/aria) [ ### Accessibility Accessibility means designing websites, apps and digital documents so that everyone can use them, including people with visual, hearing, motor or cognitive disabilities. ](https://insideuxdesign.com/en/glossar/accessibility) [ ### Affordance An affordance describes what action an object makes possible and whether people can recognize it: a button invites you to press it, a handle invites you to pull. ](https://insideuxdesign.com/en/glossar/affordance) [ ### Alt Text Alt text is a short text version of an image, stored in the HTML alt attribute. Screen readers read it aloud so people who can’t see the image get the same information. ](https://insideuxdesign.com/en/glossar/alt-text) [ ### Atomic Design Atomic Design is a method for building user interfaces from small, reusable building blocks, from single elements like buttons all the way up to complete pages. ](https://insideuxdesign.com/en/glossar/atomic-design) [ ### BFSG The BFSG, Germany’s Accessibility Strengthening Act, has required many companies since 28 June 2025 to make certain products and digital services, such as online shops, accessible. ](https://insideuxdesign.com/en/glossar/bfsg) [ ### Card Sorting Card sorting is a research method in which people sort terms written on cards into groups. It shows you how they mentally organize content, so you can plan navigation that makes sense to them. ](https://insideuxdesign.com/en/glossar/card-sorting) [ ### Cognitive Load Cognitive load is the mental effort it takes to understand and use an interface. The less unnecessary thinking a design demands, the easier the actual task becomes. ](https://insideuxdesign.com/en/glossar/cognitive-load) [ ### Color Vision Deficiency A color vision deficiency means someone has a harder time telling certain colors apart than most people. The most common type is red-green deficiency. ](https://insideuxdesign.com/en/glossar/color-vision-deficiency) [ ### Contextual Inquiry Contextual inquiry is a research method where you observe and interview people in their real work environment. It shows you how they actually get tasks done, not just how they describe it. ](https://insideuxdesign.com/en/glossar/contextual-inquiry) [ ### Contrast Ratio The contrast ratio describes how much two colors differ in brightness, such as text and background. WCAG requires at least 4.5:1 for normal text. ](https://insideuxdesign.com/en/glossar/contrast-ratio)