Front End Development Cheat Sheet 2026

The 30 highest-yield Front End Development facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In HTML, which input type renders a date picker in modern browsers? → type='date'
2. In Vue.js, which directive conditionally renders an element by toggling its display property? → v-show
3. What does a Voluntary Product Accessibility Template (VPAT) document? → How a product conforms to accessibility standards such as Section 508 and WCAG
4. You discover that 40% of your users are on slow 3G connections and your bundle is 4 MB. What risk does this pose? → Performance risk leading to high bounce rates and revenue loss
5. What does the HTML attribute 'loading="lazy"' on an tag enable? → Defers loading the image until it's near the viewport
6. Which meta tag is essential for making a web page render correctly on mobile devices? →
7. Under GDPR, within how many hours must a personal data breach be reported to the supervisory authority? → 72 hours
8. A Progressive Web App (PWA) uses which technology to enable offline functionality? → Service Workers
9. What problem do CSS Modules solve in large front-end projects? → They locally scope CSS class names to a component to prevent global namespace collisions
10. Which meta tag prevents browsers from performing MIME type sniffing, reducing certain injection risks? → X-Content-Type-Options: nosniff (response header)
11. In React, what is the purpose of the useState hook? → To add local state to a functional component
12. A Playwright test uses `expect(page).toHaveScreenshot()`. What will happen on the first run? → A baseline screenshot is created and saved; the test passes on first run
13. What is the primary value of case study analysis in Front End Development training? → Developing critical thinking by applying theory to realistic professional scenarios
14. What is the primary purpose of A/B testing in front-end development? → To compare two versions of a UI element to determine which performs better with real users
15. Which communication practice best reduces scope creep during a front-end project? → Documenting and getting sign-off on requirements before starting development
16. In the browser's rendering pipeline, what happens during the 'paint' phase? → The browser fills in pixels — colors, borders, shadows, and text
17. What is the purpose of the CSS `will-change` property? → Hints to the browser which properties will animate for optimization
18. In CSS, which property controls the space between an element's border and its content? → padding
19. Which technique allows a webpage to load JavaScript only when it's needed, reducing initial load time? → Code splitting and lazy loading
20. What does 'First Contentful Paint' (FCP) measure in web performance research? → The time from navigation start until the browser renders the first piece of DOM content
21. How are CSS custom properties (CSS variables) defined? → Using the --variable-name syntax within a selector scope
22. What is a risk mitigation strategy in Front End Development practice? → Implementing controls that reduce the likelihood or impact of identified risks
23. Which JavaScript method returns a new array with only the elements that pass a test function? → filter()
24. Which HTTP status code indicates a resource has been permanently moved? → 301
25. Which testing approach verifies that individual UI components render correctly in isolation without requiring a full browser environment? → Component unit testing
26. Which of the following best describes 'semantic HTML' and why it matters professionally? → Using HTML elements according to their intended meaning to improve accessibility and SEO
27. What is the purpose of a robots.txt file in the context of regulatory compliance? → It can direct crawlers away from pages containing sensitive or regulated data
28. Your team is about to migrate from a legacy CSS framework to a new one across 200 components. The HIGHEST risk you should plan for is: → Visual regressions across components that break the UI for end users
29. What does `event.stopPropagation()` do in JavaScript? → Stops the event from bubbling up to parent elements
30. In Storybook, what is the purpose of 'interaction tests' (using `@storybook/test`)? → Simulating and asserting user interactions within a story to verify component behavior