screen-reader-testing

Compare original and translation side by side

🇺🇸

Original

English
🇨🇳

Translation

Chinese

Screen Reader Testing

屏幕阅读器测试

Practical guide to testing web applications with screen readers for comprehensive accessibility validation.
使用屏幕阅读器测试Web应用程序的实用指南,用于全面的无障碍性验证。

When to Use This Skill

何时使用此技能

  • Validating screen reader compatibility
  • Testing ARIA implementations
  • Debugging assistive technology issues
  • Verifying form accessibility
  • Testing dynamic content announcements
  • Ensuring navigation accessibility
  • 验证屏幕阅读器兼容性
  • 测试ARIA实现效果
  • 调试辅助技术相关问题
  • 验证表单无障碍性
  • 测试动态内容播报功能
  • 确保导航无障碍性

Core Concepts

核心概念

1. Major Screen Readers

1. 主流屏幕阅读器

Screen ReaderPlatformBrowserUsage
VoiceOvermacOS/iOSSafari~15%
NVDAWindowsFirefox/Chrome~31%
JAWSWindowsChrome/IE~40%
TalkBackAndroidChrome~10%
NarratorWindowsEdge~4%
屏幕阅读器平台浏览器使用率
VoiceOvermacOS/iOSSafari~15%
NVDAWindowsFirefox/Chrome~31%
JAWSWindowsChrome/IE~40%
TalkBackAndroidChrome~10%
NarratorWindowsEdge~4%

2. Testing Priority

2. 测试优先级

Minimum Coverage:
1. NVDA + Firefox (Windows)
2. VoiceOver + Safari (macOS)
3. VoiceOver + Safari (iOS)

Comprehensive Coverage:
+ JAWS + Chrome (Windows)
+ TalkBack + Chrome (Android)
+ Narrator + Edge (Windows)
Minimum Coverage:
1. NVDA + Firefox (Windows)
2. VoiceOver + Safari (macOS)
3. VoiceOver + Safari (iOS)

Comprehensive Coverage:
+ JAWS + Chrome (Windows)
+ TalkBack + Chrome (Android)
+ Narrator + Edge (Windows)

3. Screen Reader Modes

3. 屏幕阅读器模式

ModePurposeWhen Used
Browse/VirtualRead contentDefault reading
Focus/FormsInteract with controlsFilling forms
ApplicationCustom widgetsARIA applications
模式用途使用场景
浏览/虚拟模式读取内容默认阅读场景
焦点/表单模式与控件交互填写表单时
应用模式自定义组件交互ARIA应用场景

VoiceOver (macOS)

VoiceOver (macOS)

Setup

设置步骤

Enable: System Preferences → Accessibility → VoiceOver
Toggle: Cmd + F5
Quick Toggle: Triple-press Touch ID
Enable: System Preferences → Accessibility → VoiceOver
Toggle: Cmd + F5
Quick Toggle: Triple-press Touch ID

Essential Commands

核心命令

Navigation:
VO = Ctrl + Option (VoiceOver modifier)

VO + Right Arrow   Next element
VO + Left Arrow    Previous element
VO + Shift + Down  Enter group
VO + Shift + Up    Exit group

Reading:
VO + A             Read all from cursor
Ctrl               Stop speaking
VO + B             Read current paragraph

Interaction:
VO + Space         Activate element
VO + Shift + M     Open menu
Tab                Next focusable element
Shift + Tab        Previous focusable element

Rotor (VO + U):
Navigate by: Headings, Links, Forms, Landmarks
Left/Right Arrow   Change rotor category
Up/Down Arrow      Navigate within category
Enter              Go to item

Web Specific:
VO + Cmd + H       Next heading
VO + Cmd + J       Next form control
VO + Cmd + L       Next link
VO + Cmd + T       Next table
Navigation:
VO = Ctrl + Option (VoiceOver modifier)

VO + Right Arrow   Next element
VO + Left Arrow    Previous element
VO + Shift + Down  Enter group
VO + Shift + Up    Exit group

Reading:
VO + A             Read all from cursor
Ctrl               Stop speaking
VO + B             Read current paragraph

Interaction:
VO + Space         Activate element
VO + Shift + M     Open menu
Tab                Next focusable element
Shift + Tab        Previous focusable element

Rotor (VO + U):
Navigate by: Headings, Links, Forms, Landmarks
Left/Right Arrow   Change rotor category
Up/Down Arrow      Navigate within category
Enter              Go to item

Web Specific:
VO + Cmd + H       Next heading
VO + Cmd + J       Next form control
VO + Cmd + L       Next link
VO + Cmd + T       Next table

Testing Checklist

测试检查清单

markdown
undefined
markdown
undefined

VoiceOver Testing Checklist

VoiceOver Testing Checklist

Page Load

Page Load

  • Page title announced
  • Main landmark found
  • Skip link works
  • Page title announced
  • Main landmark found
  • Skip link works

Navigation

Navigation

  • All headings discoverable via rotor
  • Heading levels logical (H1 → H2 → H3)
  • Landmarks properly labeled
  • Skip links functional
  • All headings discoverable via rotor
  • Heading levels logical (H1 → H2 → H3)
  • Landmarks properly labeled
  • Skip links functional

Links & Buttons

Links & Buttons

  • Link purpose clear
  • Button actions described
  • New window/tab announced
  • Link purpose clear
  • Button actions described
  • New window/tab announced

Forms

Forms

  • All labels read with inputs
  • Required fields announced
  • Error messages read
  • Instructions available
  • Focus moves to errors
  • All labels read with inputs
  • Required fields announced
  • Error messages read
  • Instructions available
  • Focus moves to errors

Dynamic Content

Dynamic Content

  • Alerts announced immediately
  • Loading states communicated
  • Content updates announced
  • Modals trap focus correctly
  • Alerts announced immediately
  • Loading states communicated
  • Content updates announced
  • Modals trap focus correctly

Tables

Tables

  • Headers associated with cells
  • Table navigation works
  • Complex tables have captions
undefined
  • Headers associated with cells
  • Table navigation works
  • Complex tables have captions
undefined

Common Issues & Fixes

常见问题与修复方案

html
<!-- Issue: Button not announcing purpose -->
<button><svg>...</svg></button>

<!-- Fix -->
<button aria-label="Close dialog"><svg aria-hidden="true">...</svg></button>

<!-- Issue: Dynamic content not announced -->
<div id="results">New results loaded</div>

<!-- Fix -->
<div id="results" role="status" aria-live="polite">New results loaded</div>

<!-- Issue: Form error not read -->
<input type="email" />
<span class="error">Invalid email</span>

<!-- Fix -->
<input type="email" aria-invalid="true" aria-describedby="email-error" />
<span id="email-error" role="alert">Invalid email</span>
html
<!-- Issue: Button not announcing purpose -->
<button><svg>...</svg></button>

<!-- Fix -->
<button aria-label="Close dialog"><svg aria-hidden="true">...</svg></button>

<!-- Issue: Dynamic content not announced -->
<div id="results">New results loaded</div>

<!-- Fix -->
<div id="results" role="status" aria-live="polite">New results loaded</div>

<!-- Issue: Form error not read -->
<input type="email" />
<span class="error">Invalid email</span>

<!-- Fix -->
<input type="email" aria-invalid="true" aria-describedby="email-error" />
<span id="email-error" role="alert">Invalid email</span>

NVDA (Windows)

NVDA (Windows)

Setup

设置步骤

Download: nvaccess.org
Start: Ctrl + Alt + N
Stop: Insert + Q
Download: nvaccess.org
Start: Ctrl + Alt + N
Stop: Insert + Q

Essential Commands

核心命令

Navigation:
Insert = NVDA modifier

Down Arrow         Next line
Up Arrow           Previous line
Tab                Next focusable
Shift + Tab        Previous focusable

Reading:
NVDA + Down Arrow  Say all
Ctrl               Stop speech
NVDA + Up Arrow    Current line

Headings:
H                  Next heading
Shift + H          Previous heading
1-6                Heading level 1-6

Forms:
F                  Next form field
B                  Next button
E                  Next edit field
X                  Next checkbox
C                  Next combo box

Links:
K                  Next link
U                  Next unvisited link
V                  Next visited link

Landmarks:
D                  Next landmark
Shift + D          Previous landmark

Tables:
T                  Next table
Ctrl + Alt + Arrows Navigate cells

Elements List (NVDA + F7):
Shows all links, headings, form fields, landmarks
Navigation:
Insert = NVDA modifier

Down Arrow         Next line
Up Arrow           Previous line
Tab                Next focusable
Shift + Tab        Previous focusable

Reading:
NVDA + Down Arrow  Say all
Ctrl               Stop speech
NVDA + Up Arrow    Current line

Headings:
H                  Next heading
Shift + H          Previous heading
1-6                Heading level 1-6

Forms:
F                  Next form field
B                  Next button
E                  Next edit field
X                  Next checkbox
C                  Next combo box

Links:
K                  Next link
U                  Next unvisited link
V                  Next visited link

Landmarks:
D                  Next landmark
Shift + D          Previous landmark

Tables:
T                  Next table
Ctrl + Alt + Arrows Navigate cells

Elements List (NVDA + F7):
Shows all links, headings, form fields, landmarks

Browse vs Focus Mode

浏览模式与焦点模式

NVDA automatically switches modes:
- Browse Mode: Arrow keys navigate content
- Focus Mode: Arrow keys control interactive elements

Manual switch: NVDA + Space

Watch for:
- "Browse mode" announcement when navigating
- "Focus mode" when entering form fields
- Application role forces forms mode
NVDA automatically switches modes:
- Browse Mode: Arrow keys navigate content
- Focus Mode: Arrow keys control interactive elements

Manual switch: NVDA + Space

Watch for:
- "Browse mode" announcement when navigating
- "Focus mode" when entering form fields
- Application role forces forms mode

Testing Script

测试脚本

markdown
undefined
markdown
undefined

NVDA Test Script

NVDA Test Script

Initial Load

Initial Load

  1. Navigate to page
  2. Let page finish loading
  3. Press Insert + Down to read all
  4. Note: Page title, main content identified?
  1. Navigate to page
  2. Let page finish loading
  3. Press Insert + Down to read all
  4. Note: Page title, main content identified?

Landmark Navigation

Landmark Navigation

  1. Press D repeatedly
  2. Check: All main areas reachable?
  3. Check: Landmarks properly labeled?
  1. Press D repeatedly
  2. Check: All main areas reachable?
  3. Check: Landmarks properly labeled?

Heading Navigation

Heading Navigation

  1. Press Insert + F7 → Headings
  2. Check: Logical heading structure?
  3. Press H to navigate headings
  4. Check: All sections discoverable?
  1. Press Insert + F7 → Headings
  2. Check: Logical heading structure?
  3. Press H to navigate headings
  4. Check: All sections discoverable?

Form Testing

Form Testing

  1. Press F to find first form field
  2. Check: Label read?
  3. Fill in invalid data
  4. Submit form
  5. Check: Errors announced?
  6. Check: Focus moved to error?
  1. Press F to find first form field
  2. Check: Label read?
  3. Fill in invalid data
  4. Submit form
  5. Check: Errors announced?
  6. Check: Focus moved to error?

Interactive Elements

Interactive Elements

  1. Tab through all interactive elements
  2. Check: Each announces role and state
  3. Activate buttons with Enter/Space
  4. Check: Result announced?
  1. Tab through all interactive elements
  2. Check: Each announces role and state
  3. Activate buttons with Enter/Space
  4. Check: Result announced?

Dynamic Content

Dynamic Content

  1. Trigger content update
  2. Check: Change announced?
  3. Open modal
  4. Check: Focus trapped?
  5. Close modal
  6. Check: Focus returns?
undefined
  1. Trigger content update
  2. Check: Change announced?
  3. Open modal
  4. Check: Focus trapped?
  5. Close modal
  6. Check: Focus returns?
undefined

JAWS (Windows)

JAWS (Windows)

Essential Commands

核心命令

Start: Desktop shortcut or Ctrl + Alt + J
Virtual Cursor: Auto-enabled in browsers

Navigation:
Arrow keys         Navigate content
Tab                Next focusable
Insert + Down      Read all
Ctrl               Stop speech

Quick Keys:
H                  Next heading
T                  Next table
F                  Next form field
B                  Next button
G                  Next graphic
L                  Next list
;                  Next landmark

Forms Mode:
Enter              Enter forms mode
Numpad +           Exit forms mode
F5                 List form fields

Lists:
Insert + F7        Link list
Insert + F6        Heading list
Insert + F5        Form field list

Tables:
Ctrl + Alt + Arrows Table navigation
Start: Desktop shortcut or Ctrl + Alt + J
Virtual Cursor: Auto-enabled in browsers

Navigation:
Arrow keys         Navigate content
Tab                Next focusable
Insert + Down      Read all
Ctrl               Stop speech

Quick Keys:
H                  Next heading
T                  Next table
F                  Next form field
B                  Next button
G                  Next graphic
L                  Next list
;                  Next landmark

Forms Mode:
Enter              Enter forms mode
Numpad +           Exit forms mode
F5                 List form fields

Lists:
Insert + F7        Link list
Insert + F6        Heading list
Insert + F5        Form field list

Tables:
Ctrl + Alt + Arrows Table navigation

TalkBack (Android)

TalkBack (Android)

Setup

设置步骤

Enable: Settings → Accessibility → TalkBack
Toggle: Hold both volume buttons 3 seconds
Enable: Settings → Accessibility → TalkBack
Toggle: Hold both volume buttons 3 seconds

Gestures

手势操作

Explore: Drag finger across screen
Next: Swipe right
Previous: Swipe left
Activate: Double tap
Scroll: Two finger swipe

Reading Controls (swipe up then right):
- Headings
- Links
- Controls
- Characters
- Words
- Lines
- Paragraphs
Explore: Drag finger across screen
Next: Swipe right
Previous: Swipe left
Activate: Double tap
Scroll: Two finger swipe

Reading Controls (swipe up then right):
- Headings
- Links
- Controls
- Characters
- Words
- Lines
- Paragraphs

Common Test Scenarios

常见测试场景

1. Modal Dialog

1. 模态对话框

html
<!-- Accessible modal structure -->
<div
  role="dialog"
  aria-modal="true"
  aria-labelledby="dialog-title"
  aria-describedby="dialog-desc"
>
  <h2 id="dialog-title">Confirm Delete</h2>
  <p id="dialog-desc">This action cannot be undone.</p>
  <button>Cancel</button>
  <button>Delete</button>
</div>
javascript
// Focus management
function openModal(modal) {
  // Store last focused element
  lastFocus = document.activeElement;

  // Move focus to modal
  modal.querySelector("h2").focus();

  // Trap focus
  modal.addEventListener("keydown", trapFocus);
}

function closeModal(modal) {
  // Return focus
  lastFocus.focus();
}

function trapFocus(e) {
  if (e.key === "Tab") {
    const focusable = modal.querySelectorAll(
      'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
    );
    const first = focusable[0];
    const last = focusable[focusable.length - 1];

    if (e.shiftKey && document.activeElement === first) {
      last.focus();
      e.preventDefault();
    } else if (!e.shiftKey && document.activeElement === last) {
      first.focus();
      e.preventDefault();
    }
  }

  if (e.key === "Escape") {
    closeModal(modal);
  }
}
html
<!-- Accessible modal structure -->
<div
  role="dialog"
  aria-modal="true"
  aria-labelledby="dialog-title"
  aria-describedby="dialog-desc"
>
  <h2 id="dialog-title">Confirm Delete</h2>
  <p id="dialog-desc">This action cannot be undone.</p>
  <button>Cancel</button>
  <button>Delete</button>
</div>
javascript
// Focus management
function openModal(modal) {
  // Store last focused element
  lastFocus = document.activeElement;

  // Move focus to modal
  modal.querySelector("h2").focus();

  // Trap focus
  modal.addEventListener("keydown", trapFocus);
}

function closeModal(modal) {
  // Return focus
  lastFocus.focus();
}

function trapFocus(e) {
  if (e.key === "Tab") {
    const focusable = modal.querySelectorAll(
      'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
    );
    const first = focusable[0];
    const last = focusable[focusable.length - 1];

    if (e.shiftKey && document.activeElement === first) {
      last.focus();
      e.preventDefault();
    } else if (!e.shiftKey && document.activeElement === last) {
      first.focus();
      e.preventDefault();
    }
  }

  if (e.key === "Escape") {
    closeModal(modal);
  }
}

2. Live Regions

2. 实时区域

html
<!-- Status messages (polite) -->
<div role="status" aria-live="polite" aria-atomic="true">
  <!-- Content updates will be announced after current speech -->
</div>

<!-- Alerts (assertive) -->
<div role="alert" aria-live="assertive">
  <!-- Content updates interrupt current speech -->
</div>

<!-- Progress updates -->
<div
  role="progressbar"
  aria-valuenow="75"
  aria-valuemin="0"
  aria-valuemax="100"
  aria-label="Upload progress"
></div>

<!-- Log (additions only) -->
<div role="log" aria-live="polite" aria-relevant="additions">
  <!-- New messages announced, removals not -->
</div>
html
<!-- Status messages (polite) -->
<div role="status" aria-live="polite" aria-atomic="true">
  <!-- Content updates will be announced after current speech -->
</div>

<!-- Alerts (assertive) -->
<div role="alert" aria-live="assertive">
  <!-- Content updates interrupt current speech -->
</div>

<!-- Progress updates -->
<div
  role="progressbar"
  aria-valuenow="75"
  aria-valuemin="0"
  aria-valuemax="100"
  aria-label="Upload progress"
></div>

<!-- Log (additions only) -->
<div role="log" aria-live="polite" aria-relevant="additions">
  <!-- New messages announced, removals not -->
</div>

3. Tab Interface

3. 标签页界面

html
<div role="tablist" aria-label="Product information">
  <button role="tab" id="tab-1" aria-selected="true" aria-controls="panel-1">
    Description
  </button>
  <button
    role="tab"
    id="tab-2"
    aria-selected="false"
    aria-controls="panel-2"
    tabindex="-1"
  >
    Reviews
  </button>
</div>

<div role="tabpanel" id="panel-1" aria-labelledby="tab-1">
  Product description content...
</div>

<div role="tabpanel" id="panel-2" aria-labelledby="tab-2" hidden>
  Reviews content...
</div>
javascript
// Tab keyboard navigation
tablist.addEventListener("keydown", (e) => {
  const tabs = [...tablist.querySelectorAll('[role="tab"]')];
  const index = tabs.indexOf(document.activeElement);

  let newIndex;
  switch (e.key) {
    case "ArrowRight":
      newIndex = (index + 1) % tabs.length;
      break;
    case "ArrowLeft":
      newIndex = (index - 1 + tabs.length) % tabs.length;
      break;
    case "Home":
      newIndex = 0;
      break;
    case "End":
      newIndex = tabs.length - 1;
      break;
    default:
      return;
  }

  tabs[newIndex].focus();
  activateTab(tabs[newIndex]);
  e.preventDefault();
});
html
<div role="tablist" aria-label="Product information">
  <button role="tab" id="tab-1" aria-selected="true" aria-controls="panel-1">
    Description
  </button>
  <button
    role="tab"
    id="tab-2"
    aria-selected="false"
    aria-controls="panel-2"
    tabindex="-1"
  >
    Reviews
  </button>
</div>

<div role="tabpanel" id="panel-1" aria-labelledby="tab-1">
  Product description content...
</div>

<div role="tabpanel" id="panel-2" aria-labelledby="tab-2" hidden>
  Reviews content...
</div>
javascript
// Tab keyboard navigation
tablist.addEventListener("keydown", (e) => {
  const tabs = [...tablist.querySelectorAll('[role="tab"]')];
  const index = tabs.indexOf(document.activeElement);

  let newIndex;
  switch (e.key) {
    case "ArrowRight":
      newIndex = (index + 1) % tabs.length;
      break;
    case "ArrowLeft":
      newIndex = (index - 1 + tabs.length) % tabs.length;
      break;
    case "Home":
      newIndex = 0;
      break;
    case "End":
      newIndex = tabs.length - 1;
      break;
    default:
      return;
  }

  tabs[newIndex].focus();
  activateTab(tabs[newIndex]);
  e.preventDefault();
});

Debugging Tips

调试技巧

javascript
// Log what screen reader sees
function logAccessibleName(element) {
  const computed = window.getComputedStyle(element);
  console.log({
    role: element.getAttribute("role") || element.tagName,
    name:
      element.getAttribute("aria-label") ||
      element.getAttribute("aria-labelledby") ||
      element.textContent,
    state: {
      expanded: element.getAttribute("aria-expanded"),
      selected: element.getAttribute("aria-selected"),
      checked: element.getAttribute("aria-checked"),
      disabled: element.disabled,
    },
    visible: computed.display !== "none" && computed.visibility !== "hidden",
  });
}
javascript
// Log what screen reader sees
function logAccessibleName(element) {
  const computed = window.getComputedStyle(element);
  console.log({
    role: element.getAttribute("role") || element.tagName,
    name:
      element.getAttribute("aria-label") ||
      element.getAttribute("aria-labelledby") ||
      element.textContent,
    state: {
      expanded: element.getAttribute("aria-expanded"),
      selected: element.getAttribute("aria-selected"),
      checked: element.getAttribute("aria-checked"),
      disabled: element.disabled,
    },
    visible: computed.display !== "none" && computed.visibility !== "hidden",
  });
}

Best Practices

最佳实践

Do's

建议

  • Test with actual screen readers - Not just simulators
  • Use semantic HTML first - ARIA is supplemental
  • Test in browse and focus modes - Different experiences
  • Verify focus management - Especially for SPAs
  • Test keyboard only first - Foundation for SR testing
  • 使用真实屏幕阅读器测试 - 不要仅依赖模拟器
  • 优先使用语义化HTML - ARIA仅作为补充
  • 测试浏览和焦点两种模式 - 两种模式体验不同
  • 验证焦点管理 - 尤其是单页应用(SPA)
  • 先测试纯键盘操作 - 这是屏幕阅读器测试的基础

Don'ts

禁忌

  • Don't assume one SR is enough - Test multiple
  • Don't ignore mobile - Growing user base
  • Don't test only happy path - Test error states
  • Don't skip dynamic content - Most common issues
  • Don't rely on visual testing - Different experience
  • 不要仅依赖一种屏幕阅读器 - 测试多种主流工具
  • 不要忽略移动端 - 移动端用户群体正在增长
  • 不要仅测试正常流程 - 需测试错误状态
  • 不要跳过动态内容 - 这是最常见的问题点
  • 不要仅依赖视觉测试 - 屏幕阅读器的体验与视觉完全不同

Resources

参考资源