# UX Heuristics > Evaluate a UI against Nielsen's 10 Usability Heuristics — score each heuristic, flag violations with severity ratings, and produce a prioritized fix list. Use when the user asks for a "UX review", "usability audit", "heuristic evaluation", or "why is this UI confusing to users". Do NOT use for code quality or accessibility — use output-enforcement or accessibility-audit for those. - Skill: `yanacuti1121/ux-heuristics` (Agent Skill) - Install (CLI): `npx skillmds add yanacuti1121/ux-heuristics` - Raw SKILL.md: https://api.skillmd.com/api/skills/yanacuti1121/ux-heuristics/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Web & Frontend - Author: yanacuti1121 (https://skillmd.com/u/yanacuti1121) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/yanacuti1121/ux-heuristics --- ## When to Use - Use when: user says "why is this confusing", "users keep making mistakes", "UX review" - Use when: reviewing a design before user testing - Use when: diagnosing a specific UX complaint ("users can't find X") - Do NOT use for visual aesthetics — use `ui-redesign` or `design-taste-frontend` - Do NOT use for accessibility compliance — use `accessibility-audit` ## The 10 Heuristics ### H1 — Visibility of System Status *The system always keeps users informed about what is going on.* Check for: - Loading states present on async operations - Progress indicators for multi-step processes - Clear feedback after actions (success/error messages) - Active states on navigation items ### H2 — Match Between System and Real World *The system speaks the users' language.* Check for: - Technical jargon used where plain language would work - Icons whose meaning is not universally understood (no tooltips) - Dates, numbers, currencies in non-user locale format - Metaphors that don't match user mental models ### H3 — User Control and Freedom *Users can undo mistakes and exit unwanted states.* Check for: - No undo/cancel on destructive actions - No way to exit a flow mid-way - Modals/dialogs with no close option - Back button behavior inconsistent with user expectation ### H4 — Consistency and Standards *Users should not have to wonder whether different words, situations, or actions mean the same thing.* Check for: - Same action labeled differently in different places - Similar UI elements that behave differently - Platform conventions broken (right-click, swipe, keyboard shortcuts) - Inconsistent button placement across screens ### H5 — Error Prevention *Design carefully to prevent problems from occurring.* Check for: - Forms allow invalid input with no real-time validation - Destructive actions with no confirmation step - Ambiguous options that users might misclick - No constraints on inputs that have known valid ranges ### H6 — Recognition Rather than Recall *Minimize the user's memory load.* Check for: - Actions or options only available from memory (no visible affordances) - Form fields don't show what format is expected - No breadcrumbs or context indicators in complex flows - Commands that must be remembered rather than recognized ### H7 — Flexibility and Efficiency of Use *Accelerators for expert users, not at the expense of novices.* Check for: - No keyboard shortcuts for power users - Repetitive tasks with no shortcut or bulk action - Advanced options completely hidden from everyone (not just collapsed) - No way to customize frequent workflows ### H8 — Aesthetic and Minimalist Design *Dialogues should not contain irrelevant or rarely needed information.* Check for: - Every visible element serves a purpose or an action - Information hierarchy unclear — secondary info competes with primary - Marketing copy in UI flow (task completion ≠ marketing moment) - Visual noise that dilutes important content ### H9 — Help Users Recognize, Diagnose, and Recover from Errors *Error messages should be expressed in plain language, precisely indicate the problem, and constructively suggest a solution.* Check for: - Error messages that say what went wrong but not how to fix it - Error codes shown without human explanation - Errors that disappear before the user can read them - Form errors not linked to the specific field that caused them ### H10 — Help and Documentation *Even though it is better if the system can be used without documentation, it may be necessary.* Check for: - Complex features with no help text or tooltip - Empty states with no guidance on what to do - Onboarding that assumes prior knowledge - Help content that requires leaving the current task --- ## Severity Scale Score each violation 0–4: | Score | Label | Meaning | |-------|-------|---------| | 0 | Not a problem | Can be ignored | | 1 | Cosmetic | Fix only if time permits | | 2 | Minor | Low priority | | 3 | Major | High priority — fix before ship | | 4 | Catastrophic | Must fix — blocks usability | ## How It Works 1. **Read or view the UI** — code, screenshot, or description 2. **Evaluate each of the 10 heuristics** — one by one, no skipping 3. **Record violations** with severity 1–4 (severity 0 = skip) 4. **Sort by severity** — 4 first, then 3, then 2, then 1 5. **Produce fix list** — specific, actionable, one fix per violation ## Output Format ``` ## UX Heuristics Evaluation H1 — Visibility of System Status PASS H2 — Match Between System and World VIOLATION (severity 2) Issue: "Submit" button on invoice form — users unfamiliar with accounting don't know if this sends or just saves. Fix: Rename to "Send Invoice" — makes action explicit. H3 — User Control and Freedom VIOLATION (severity 4) Issue: No way to cancel a payment once "Confirm" is clicked. Fix: Add 30-second undo window with toast notification. ... ## Summary Violations: 6 (1× severity-4, 2× severity-3, 2× severity-2, 1× severity-1) Must fix before ship: H3 (catastrophic), H9 (major), H1 (major) ``` ## Gotchas - H8 (minimalist design) is about information density, not visual aesthetics — a visually busy UI can pass H8 if every element serves a purpose - Evaluate from the user's perspective, not the developer's — "it's obvious" is not evidence - A single screen may have violations of multiple heuristics simultaneously - Severity 4 must block delivery — do not report it and move on ## Anti-Fake-Pass Rules Before claiming the evaluation is done, you MUST show: - [ ] All 10 heuristics evaluated — none skipped without explicit N/A reason - [ ] Each violation has: heuristic number, severity score, specific UI element, concrete fix - [ ] Summary: total violations by severity level - [ ] Must-fix list identified (severity 3–4) Reference: `gates/anti-fake-pass-gate.md`