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( Rules library )

Every Flag, Explained.

Every rule maps back to a WCAG success criterion, an impact level and a plain-English fix path. Most run automatically in a scan; the rest are flagged for manual review or included as reference guidance.

Automatically checked
96
Manual & guidance only
26
WCAG criteria
48
Critical checks
17
Showing 122 of 122 rules

Perceivable

Perceivable rules 43

These rules make sure people can receive the content in the first place, whether they use a screen reader, captions, zoomed text, high contrast settings, or custom spacing. They cover text alternatives, media, colour, contrast, and presentation details that decide whether information is visible, audible, or available to assistive technology.

  1. Serious Level A ARIA meter has no accessible name WCAG 1.1.1 - Non-text Content
  2. Serious Level A ARIA progressbar has no accessible name WCAG 1.1.1 - Non-text Content
  3. Critical Level A Image is missing alt text WCAG 1.1.1 - Non-text Content
  4. Serious Level A Alt text is a filename or placeholder WCAG 1.1.1 - Non-text Content
  5. Serious Level A Image map area element is missing alt text WCAG 1.1.1 - Non-text Content
  6. Minor Level A Decorative image is not hidden from assistive technology WCAG 1.1.1 - Non-text Content
  7. Serious Level A Alt text is a raw filename WCAG 1.1.1 - Non-text Content
  8. Serious Level A Image input is missing alt text WCAG 1.1.1 - Non-text Content
  9. Serious Level A Object element has no text alternative WCAG 1.1.1 - Non-text Content
  10. Minor Level A Alt text repeats adjacent visible text WCAG 1.1.1 - Non-text Content
  11. Serious Level A role="img" element has no accessible text WCAG 1.1.1 - Non-text Content
  12. Serious Level A SVG image has no accessible label WCAG 1.1.1 - Non-text Content
  13. Critical Level A Manual / guidance Audio element has no caption track WCAG 1.2.1 - Audio-only and Video-only (Prerecorded)
  14. Critical Level A Video is missing captions WCAG 1.2.2 - Captions (Prerecorded)
  15. Serious Level A Element role is missing required child elements WCAG 1.3.1 - Info and Relationships
  16. Serious Level A ARIA element is missing a required parent role WCAG 1.3.1 - Info and Relationships
  17. Moderate Level A Definition list structure is invalid WCAG 1.3.1 - Info and Relationships
  18. Serious Level A Definition list item used outside a dl element WCAG 1.3.1 - Info and Relationships
  19. Critical Level A Form input has no label WCAG 1.3.1 - Info and Relationships
  20. Serious Level A List contains an element other than li WCAG 1.3.1 - Info and Relationships
  21. Moderate Level A List items are not contained within a list element WCAG 1.3.1 - Info and Relationships
  22. Moderate Level A Manual / guidance Related form inputs are missing fieldset and legend WCAG 1.3.1 - Info and Relationships
  23. Moderate Level A Heading levels are skipped WCAG 1.3.1 - Info and Relationships
  24. Serious Level A Hidden component exposed to screen readers WCAG 1.3.1 - Info and Relationships
  25. Serious Level A Input only uses placeholder as its label WCAG 1.3.1 - Info and Relationships
  26. Minor Level A Presentational markup used instead of semantic elements WCAG 1.3.1 - Info and Relationships
  27. Moderate Level A Manual / guidance Table header scope value is invalid WCAG 1.3.1 - Info and Relationships
  28. Moderate Level A Manual / guidance Complex data table is missing a caption WCAG 1.3.1 - Info and Relationships
  29. Serious Level A Table is missing header cells WCAG 1.3.1 - Info and Relationships
  30. Serious Level A Table cell headers attribute references a missing id WCAG 1.3.1 - Info and Relationships
  31. Serious Level A Table header has no associated data cells WCAG 1.3.1 - Info and Relationships
  32. Moderate Level A Manual / guidance CSS flex or grid order does not match DOM order WCAG 1.3.2 - Meaningful Sequence
  33. Serious Level AA CSS locks content to a single orientation WCAG 1.3.4 - Orientation
  34. Moderate Level AA Form field autocomplete attribute is missing or invalid WCAG 1.3.5 - Identify Input Purpose
  35. Serious Level A Link is not distinguishable from surrounding text without color WCAG 1.4.1 - Use of Color
  36. Serious Level A Page auto-plays audio or video with sound WCAG 1.4.2 - Audio Control
  37. Serious Level AA Text does not have enough colour contrast WCAG 1.4.3 - Contrast (Minimum)
  38. Serious Level AA Text contrast fails after a hover, focus, or state change WCAG 1.4.3 - Contrast (Minimum)
  39. Critical Level AA Viewport zoom is disabled WCAG 1.4.4 - Resize Text
  40. Moderate Level AAA Manual / guidance Text does not meet enhanced AAA contrast requirements WCAG 1.4.6 - Contrast (Enhanced)
  41. Serious Level AA Manual / guidance UI component has insufficient contrast WCAG 1.4.11 - Non-text Contrast
  42. Serious Level AA Text spacing overrides break the layout WCAG 1.4.12 - Text Spacing
  43. Serious Level AA Manual / guidance Content on hover or focus cannot be dismissed WCAG 1.4.13 - Content on Hover or Focus

Operable

Operable rules 35

These rules check that people can move through a page and use controls without getting trapped or losing their place. They affect keyboard users, switch device users, screen reader users, and anyone who depends on clear focus order, safe timing, predictable navigation, and reliable interaction patterns.

  1. Serious Level A Focus skipped an interactive element WCAG 2.1.1 - Keyboard
  2. Serious Level A Frame with focusable content has no accessible name WCAG 2.1.1 - Keyboard
  3. Critical Level A Manual / guidance Interactive element is not reachable by keyboard WCAG 2.1.1 - Keyboard
  4. Moderate Level A Scrollable region must be keyboard accessible WCAG 2.1.1 - Keyboard
  5. Serious Level A Server-side image map is used WCAG 2.1.1 - Keyboard
  6. Serious Level A Focus is trapped inside a component WCAG 2.1.2 - No Keyboard Trap
  7. Serious Level A Meta refresh causes automatic page redirect WCAG 2.2.1 - Timing Adjustable
  8. Serious Level A Session times out without warning WCAG 2.2.1 - Timing Adjustable
  9. Serious Level A Page contains a blinking or scrolling element WCAG 2.2.2 - Pause, Stop, Hide
  10. Serious Level A marquee element is used WCAG 2.2.2 - Pause, Stop, Hide
  11. Moderate Level AAA Page uses meta refresh with a time limit WCAG 2.2.4 - Interruptions
  12. Critical Level A Manual / guidance Content flashes more than 3 times per second WCAG 2.3.1 - Three Flashes or Below Threshold
  13. Moderate Level AAA Page animations have no reduced motion alternative WCAG 2.3.3 - Animation from Interactions
  14. Moderate Level A Page has no skip navigation link WCAG 2.4.1 - Bypass Blocks
  15. Moderate Level A Skip link target is missing or not focusable WCAG 2.4.1 - Bypass Blocks
  16. Moderate Level A Page is missing a descriptive title WCAG 2.4.2 - Page Titled
  17. Minor Level A Element in the focus order has no matching interactive role WCAG 2.4.3 - Focus Order
  18. Serious Level A Modal opens without moving focus into it WCAG 2.4.3 - Focus Order
  19. Moderate Level A Modal is missing focus management WCAG 2.4.3 - Focus Order
  20. Serious Level A Manual check flagged an incorrect tab order WCAG 2.4.3 - Focus Order
  21. Moderate Level A Element has a positive tabindex WCAG 2.4.3 - Focus Order
  22. Moderate Level A Tab order doesn't match visual order WCAG 2.4.3 - Focus Order
  23. Serious Level A Link must have discernible text WCAG 2.4.4, 4.1.2 - Link Purpose (In Context); Name, Role, Value
  24. Minor Level A Link opens a file with no format or size warning WCAG 2.4.4 - Link Purpose (In Context)
  25. Moderate Level A Link text is generic and gives no context WCAG 2.4.4 - Link Purpose (In Context)
  26. Moderate Level AA Heading is empty or contains only whitespace WCAG 2.4.6 - Headings and Labels
  27. Moderate Level AA Heading doesn't describe its section WCAG 2.4.6 - Headings and Labels
  28. Moderate Level AA Label is ambiguous without surrounding context WCAG 2.4.6 - Headings and Labels
  29. Moderate Level AA Label doesn't make sense in context WCAG 2.4.6 - Headings and Labels
  30. Serious Level AA Focused element has no visible focus indicator WCAG 2.4.7 - Focus Visible
  31. Minor Level AAA Links with the same accessible name go to different places WCAG 2.4.9 - Link Purpose (Link Only)
  32. Serious Level AA Manual / guidance Focus indicator does not meet minimum size or contrast WCAG 2.4.11 - Focus Appearance
  33. Serious Level AA Focused element is hidden behind a sticky header or footer WCAG 2.4.12 - Focus Not Obscured
  34. Serious Level AA Dragging interaction has no pointer alternative WCAG 2.5.7 - Dragging Movements
  35. Moderate Level AA Interactive element is too small to tap accurately WCAG 2.5.8 - Target Size (Minimum)

Understandable

Understandable rules 16

These rules make interfaces easier to read, predict, and recover from when something goes wrong. They affect people with cognitive, language, learning, memory, or attention needs, and cover page language, labels, instructions, errors, and behaviour that should not surprise users.

  1. Serious Level A Page language is not set WCAG 3.1.1 - Language of Page
  2. Serious Level A lang attribute has an invalid value WCAG 3.1.1 - Language of Page
  3. Moderate Level A lang and xml:lang do not match WCAG 3.1.1 - Language of Page
  4. Serious Level A Page is missing a language declaration WCAG 3.1.1 - Language of Page
  5. Moderate Level A Manual / guidance HTML lang attribute is not a valid BCP 47 tag WCAG 3.1.1 - Language of Page
  6. Serious Level AA lang attribute on an element has an invalid value WCAG 3.1.2 - Language of Parts
  7. Serious Level A Manual / guidance Context change happens when element receives focus WCAG 3.2.1 - On Focus
  8. Moderate Level A Manual / guidance Link opens in a new tab without warning text WCAG 3.2.2 - On Input
  9. Serious Level A Manual / guidance Context change happens on input without warning WCAG 3.2.2 - On Input
  10. Moderate Level AA Manual / guidance Navigation order is inconsistent across pages WCAG 3.2.3 - Consistent Navigation
  11. Moderate Level A Manual / guidance Help mechanism location is inconsistent across pages WCAG 3.2.6 - Consistent Help
  12. Serious Level A Manual / guidance Form error is not clearly identified WCAG 3.3.1 - Error Identification
  13. Moderate Level A Form field has more than one label WCAG 3.3.2 - Labels or Instructions
  14. Serious Level AA Manual / guidance Error message does not explain how to fix input WCAG 3.3.3 - Error Suggestion
  15. Moderate Level A Manual / guidance User must re-enter information already provided in the same process WCAG 3.3.7 - Redundant Entry
  16. Serious Level AA Manual / guidance Accessible authentication requires cognitive function test WCAG 3.3.8 - Accessible Authentication (Minimum)

Robust

Robust rules 28

These rules make sure the underlying HTML and accessibility tree can be interpreted consistently by browsers and assistive technology. They cover valid semantics, accessible names, roles, relationships, and markup patterns that screen readers, browser tools, and automation rely on.

  1. Serious Level A Manual / guidance Duplicate id on active, focusable elements WCAG 4.1.1 - Parsing
  2. Moderate Level A Manual / guidance Duplicate ID attributes found on the page WCAG 4.1.1 - Parsing
  3. Moderate Level A ARIA attribute is not allowed for this role WCAG 4.1.2 - Name, Role, Value
  4. Serious Level A aria-braillelabel or aria-brailleroledescription has no equivalent WCAG 4.1.2 - Name, Role, Value
  5. Serious Level A ARIA command has no accessible name WCAG 4.1.2 - Name, Role, Value
  6. Serious Level A ARIA attribute is not valid for the current role value WCAG 4.1.2 - Name, Role, Value
  7. Serious Level A Element uses a deprecated ARIA role WCAG 4.1.2 - Name, Role, Value
  8. Critical Level A aria-hidden="true" is present on the document body WCAG 4.1.2 - Name, Role, Value
  9. Critical Level A Focusable element is inside an aria-hidden container WCAG 4.1.2 - Name, Role, Value
  10. Serious Level A ARIA input field has no accessible name WCAG 4.1.2 - Name, Role, Value
  11. Serious Level A ARIA attribute is prohibited for this role WCAG 4.1.2 - Name, Role, Value
  12. Critical Level A Required ARIA attribute is missing WCAG 4.1.2 - Name, Role, Value
  13. Critical Level A ARIA role is invalid WCAG 4.1.2 - Name, Role, Value
  14. Serious Level A ARIA toggle field has no accessible name WCAG 4.1.2 - Name, Role, Value
  15. Serious Level A ARIA tooltip has no accessible name WCAG 4.1.2 - Name, Role, Value
  16. Critical Level A ARIA attribute has an invalid value WCAG 4.1.2 - Name, Role, Value
  17. Critical Level A ARIA attribute name is not valid WCAG 4.1.2 - Name, Role, Value
  18. Critical Level A Button or link has no accessible name WCAG 4.1.2 - Name, Role, Value
  19. Critical Level A Duplicate id used in an ARIA reference WCAG 4.1.2 - Name, Role, Value
  20. Serious Level A Frame title is not unique WCAG 4.1.2 - Name, Role, Value
  21. Serious Level A iframe has no accessible title WCAG 4.1.2 - Name, Role, Value
  22. Critical Level A Input button has no accessible name WCAG 4.1.2 - Name, Role, Value
  23. Serious Level A Interactive controls are nested inside each other WCAG 4.1.2 - Name, Role, Value
  24. Moderate Level A Manual / guidance Expandable control is missing aria-expanded WCAG 4.1.2 - Name, Role, Value
  25. Serious Level A Manual / guidance Dialog or modal has no accessible name WCAG 4.1.2 - Name, Role, Value
  26. Critical Level A Interactive element has no accessible name at all WCAG 4.1.2 - Name, Role, Value
  27. Serious Level A Select element has no accessible name WCAG 4.1.2 - Name, Role, Value
  28. Serious Level AA Manual / guidance Status messages are not announced to assistive tech WCAG 4.1.3 - Status Messages