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Accessibility

· 24 checks — Landmarks, headings, alt text, forms, and link quality rolled into one auditable list.
SCORE
85
GRADE
B
FIX
2
REVIEW
5
PASS
17
INFO
0
Checks
24
17 PASS 5 REVIEW 2 FIX
D
Print Stylesheet
Action
No print styles
FIX
No print styles
Info::
No print-specific styles detected
When users print this page, they get the screen layout including navigation and non-essential elements. Add @media print rules to hide navigation and optimize layout for paper.
Print Stylesheet No Print Styles
Print stylesheet Not found ✗Inline @media print Not detected ✗
F
Navigation UX
Action
No navigation patterns
FIX
No navigation patterns
Info::
1 navigation landmark(s) detected
Info::
Hamburger menu detected (responsive design)
Info::
No breadcrumbs, search, or skip link detected
These navigation aids help users orient themselves and find content efficiently, especially on large sites.
Breadcrumbs
Search
Skip Link
Labeled Navigation 1 <nav> element(s)
Back to Top
Hamburger Menu
Sticky Navigation Cannot reliably detect (CSS-based)
2 of 6 testable patterns navigation patterns detected. Limited navigation support. Consider adding breadcrumbs, search, and skip link.
C
Landmark Structure
Action
3 landmarks
REVIEW
3 landmarks
Critical::
No <main> landmark found
Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.
Info::
1 <nav> landmark(s) found
Info::
No banner (header) landmark
Warning::
Skip navigation link is missing (WCAG 2.4.1)
Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.
Page Structure — as a screen reader sees it
BANNER (missing!) NAV MAIN (missing!) ASIDE CONTENTINFO footer

Screen reader users cannot quickly navigate to the primary content. Wrap your main content in <main>.

Why this matters

Without a <main> landmark, screen-reader users can't skip past the navigation to the page content — every page starts with re-reading the menu.

Learn more ▾

The <main> element marks the page's primary content area. Assistive tech offers a 'jump to main' shortcut — but only if <main> exists. Without it, every page navigation forces re-reading the header. Wrap your primary content in a single <main>.

Source: WAI-ARIA / WCAG 2.4.1

Add a skip link as the first focusable element so keyboard users can bypass repeated navigation.

Why this matters

Without a skip-nav link, keyboard users tab through every nav item before reaching content — every page, every visit.

Learn more ▾

WCAG 2.4.1 (Bypass Blocks) requires a mechanism to skip past repeated content. The standard implementation is a 'Skip to main content' link that's the first focusable element, visually hidden until focused. Three lines of HTML + four of CSS.

Source: WCAG 2.1 SC 2.4.1

B
Heading Hierarchy
14 headings, 1 skip(s)
REVIEW
14 headings, 1 skip(s)
Warning::
Multiple H1 headings (10 found)
A page should have only one H1. Multiple H1s dilute the document outline.
Warning::
Heading level skipped: H1 → H3 (missing H2)
Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.
  • H1 AI Agent 试图扫描 DN42 时把主人搞破产了
  • H1 魔改 FileZilla 解决拓竹 3D 打印机的 FTP 问题 duplicate H1
  • H1 在 DN42 中使用 FlapAlerted 抑制 Flapping duplicate H1
  • H1 用 Open5GS 搭建合法的 LTE 网络 duplicate H1
  • H1 在内网中免 StosVPN 使用 SideStore duplicate H1
  • H1 从零开始实现 Nix 对数函数库 duplicate H1
  • H1 $100，DIY 搭建合法的 LTE 网络 duplicate H1
  • H1 用 Nix 编译自定义 Android 内核 duplicate H1
  • H1 使用 Astro.js 重构我的博客 duplicate H1
  • H1 NixOS 系列（五）：制作小内存 VPS 的 DD 磁盘镜像 duplicate H1
  • H3 最新文章 skipped
  • H3 最新评论
  • H3 其它功能
  • H3 友情链接

A page should have only one H1. Multiple H1s dilute the document outline.

Why this matters

Multiple H1s blur the page's primary topic — screen-reader users and Google both prefer one H1.

Learn more ▾

HTML5's outline algorithm technically allows multiple H1s within sectioning content, but no browser implements it. In practice: one H1 per page. Use H2-H6 for subsections.

Source: WCAG 2.4.6 / Google Search Central

Skipping heading levels breaks the document outline. Screen readers may interpret missing levels as structural errors.

Why this matters

Skipping heading levels breaks the document outline — screen-reader users lose track of section nesting.

Learn more ▾

Screen reader users navigate by jumping between headings (H1 → H2 → H3). Skipping (H1 → H3) breaks the sense of hierarchy. Use sequential levels even if you don't like the default styling — restyle with CSS instead. WCAG 1.3.1 (Info and Relationships) treats this as an A failure.

Source: WCAG 2.1 SC 1.3.1 / W3C WAI

B
404 Error Page
HTTP 404, custom page
REVIEW
HTTP 404, custom page
Info::
Correct 404 status code returned
Got: HTTP 404
Info::
Custom styled 404 page
Info::
Navigation links present on 404 page
Info::
Homepage link present on 404 page
404 Page Quality ✓ Custom 404 Page
Status Code HTTP 404 ✓Page Title 404 Not Found - Lan Tian @ Blog ✓Custom Styling ✓Navigation ✓Homepage Link ✓Search Form ✗
B
PWA Depth
2 PWA signal(s) surfaced
REVIEW
2 PWA signal(s) surfaced
Warning::
Manifest is missing `display` -- defaults to browser, no PWA UX
When `display` is `browser` (or unset, which is the spec default), the installed app opens in a regular browser tab -- no install prompt, no standalone window, no app-shell experience. The intended values for a PWA are `standalone` (most common; full-screen, no browser chrome) or `fullscreen` (games / immersive apps). `minimal-ui` is a middle ground (basic browser controls but no address bar).
Info::
Manifest has no maskable icon
Android 12+ Adaptive Icons crop non-maskable icons to a circle or squircle -- frequently hiding important parts of the logo. Add at least one icon entry with `"purpose": "maskable"` (or `"any maskable"`) and a maskable-aware design (16% safe-zone padding around the inner mark).
B
Dark Mode Support
Dark mode detected
REVIEW
Dark mode detected
Info::
Dark-specific theme-color detected
A theme-color with media='(prefers-color-scheme: dark)' adapts the browser toolbar for dark mode.
Info::
prefers-color-scheme CSS detected in inline styles
Info::
Detection limited to meta tags and inline styles
External CSS files may contain prefers-color-scheme rules not visible to this scan.
Dark Mode✓ Dark Mode Supported
color-scheme meta Not set ✗Dark theme-color #03a9f4 ✓CSS indicators Detected ✓

Detection limited to meta tags and inline styles.

A+
Heading Text Quality
1 heading-text-quality issue(s) detected
PASS
1 heading-text-quality issue(s) detected
Info::
5 heading(s) are all-uppercase (excluding short acronyms)
Headings rendered in all-uppercase are a styling choice that should be done via CSS (`text-transform: uppercase`), not by typing the text in caps. Capitalized text is read letter-by-letter by some screen readers (e.g., "H-E-L-L-O W-O-R-L-D" instead of "hello world"). It's also a soft signal of CMS-migration artifacts where the original lowercase intent was lost.
Got: 5 all-caps heading(s)
A+
Alt Text Quality
All 3 images OK
PASS
All 3 images OK
Info::
3 image(s) with good alt text
3 images 3 good alt text
All images have appropriate alt text.
A+
Form Accessibility
No form controls
PASS
No form controls
Info::
No form controls on this page
No form controls found.
A+
Form Input Types
No form controls on this page
PASS
No form controls on this page
Info::
No form controls on this page
A+
Form Input Quality
No form controls on this page
PASS
No form controls on this page
Info::
No form controls on this page
A+
Mobile Keyboard & Autofill
No form controls -- mobile keyboard check is N/A
PASS
No form controls -- mobile keyboard check is N/A
Info::
No form controls on this page
A+
Document Language
Lang attribute set to "zh-CN"
PASS
Lang attribute set to "zh-CN"
Info::
<html lang="zh-CN"> is set and valid
Got: zh-CN
A+
Tabindex Anti-Patterns
No explicit tabindex attributes found
PASS
No explicit tabindex attributes found
Info::
No explicit tabindex attributes found
A+
Iframe Accessibility
No iframes on this page
PASS
No iframes on this page
Info::
No iframes on this page
A+
Tap Target Adequacy
All tap targets meet WCAG 2.5.5/2.5.8 sizing
PASS
All tap targets meet WCAG 2.5.5/2.5.8 sizing
Info::
All tap targets meet WCAG 2.5.5 (44x44px) sizing
A+
Mobile-Readable Font Sizes
All 55 visible text node(s) render at >= 12 CSS pixels
PASS
All 55 visible text node(s) render at >= 12 CSS pixels
Info::
All text uses legible mobile font sizes (>= 12 CSS px)
A
Favicon & Branding
28 icon(s) detected
PASS
28 icon(s) detected
Info::
favicon.ico present at site root
Info::
HTML icon links detected
Info::
Apple touch icon present
Info::
SVG favicon detected — scales perfectly to any size
Info::
Multiple icon sizes detected
✓ favicon.ico Present
✓ PNG Icons Present
✓ Apple Touch Present
✓ SVG Favicon Present
✓ Manifest Icons Present
✓ Multiple Sizes Present
A
Web Manifest
Valid manifest
PASS
Valid manifest
Info::
Name present: Lan Tian @ Blog
Info::
192x192 icon present
Info::
512x512 icon present
PWA Install Criteria Not Installable
Name Lan Tian @ Blog ✓192×192 icon ✓512×512 icon ✓Start URL https://lantian.pub ✓Display Mode ✗
Name Lan Tian @ Blog Theme Color #03a9f4 Background Color #bbdefb Icons 9 icon(s)
A+
Mobile UX Depth
1 mobile-depth signal(s) detected
PASS
1 mobile-depth signal(s) detected
Info::
Browser-chrome `theme-color` meta tag present
The page sets `<meta name="theme-color" content="...">`, which Android Chrome uses to tint the status bar and iOS Safari uses for the toolbar background. Brand polish that costs nothing and Just Works.
A+
Color Contrast (Screenshot)
20 text elements analyzed, 0 fail WCAG AA
PASS

Analyzes text contrast against the actual rendered page, including background images, gradients, and overlays that CSS-based tools cannot detect.

20 pass
Show all checked elements (20)
ElementRatioRequiredFGBGResult
h3 最新文章21.00:13.0:1
#000000
#FFFFFF
Pass
h3 最新评论21.00:13.0:1
#000000
#FFFFFF
Pass
h3 其它功能21.00:13.0:1
#000000
#FFFFFF
Pass
h3 友情链接21.00:13.0:1
#000000
#FFFFFF
Pass
title Lan Tian @ Blog15.91:14.5:1
#000000
#E0E0E0
Pass
a Lan Tian @ Blog12.81:14.5:1
#000000
#CACACA
Pass
a 文章们19.77:14.5:1
#000000
#F8F8F8
Pass
a 俯瞰地球21.00:14.5:1
#000000
#FFFFFF
Pass
a DN4221.00:14.5:1
#000000
#FFFFFF
Pass
a 页面21.00:14.5:1
#000000
#FFFFFF
Pass
a 文章们21.00:14.5:1
#000000
#FFFFFF
Pass
a 俯瞰地球21.00:14.5:1
#000000
#FFFFFF
Pass
a DN4221.00:14.5:1
#000000
#FFFFFF
Pass
a Language21.00:14.5:1
#000000
#FFFFFF
Pass
a Chinese Simplified /…21.00:14.5:1
#000000
#FFFFFF
Pass
a English21.00:14.5:1
#000000
#FFFFFF
Pass
a Not all pages have t…21.00:14.5:1
#000000
#FFFFFF
Pass
a You may see 404 - th…21.00:14.5:1
#000000
#FFFFFF
Pass
a 夜间模式21.00:14.5:1
#000000
#FFFFFF
Pass
a 自动21.00:14.5:1
#000000
#FFFFFF
Pass

Methodology: The top 20 text elements by font size were checked. Background color was sampled from the desktop screenshot using a 5-point pattern. WCAG 2.1 AA requires 4.5:1 for normal text and 3:1 for large text.

A
Lighthouse Accessibility Audits
Score 92/100 — 2 failing, 15 passed
PASS
92

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Lan Tian @ Blog div#container > nav.lantian > div.container-fluid > a.navbar-brand
05-13 div.post-meta-wrap > div.post-meta > p > small
娱乐 div.post-meta-wrap > div.post-meta > p > small
3 标签 div.post-meta-wrap > div.post-meta > p > small
AI Agent 试图扫描 DN42 时把主人搞破产了 div.d-flex > div.post-wrap > h1.post-title > a
04-13 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
4 标签 div.post-meta-wrap > div.post-meta > p > small
魔改 FileZilla 解决拓竹 3D 打印机的 FTP 问题 div.d-flex > div.post-wrap > h1.post-title > a
12-07 div.post-meta-wrap > div.post-meta > p > small
网站与服务端 div.post-meta-wrap > div.post-meta > p > small
3 标签 div.post-meta-wrap > div.post-meta > p > small
在 DN42 中使用 FlapAlerted 抑制 Flapping div.d-flex > div.post-wrap > h1.post-title > a
07-20 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
4 标签 div.post-meta-wrap > div.post-meta > p > small
用 Open5GS 搭建合法的 LTE 网络 div.d-flex > div.post-wrap > h1.post-title > a
06-27 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
3 标签 div.post-meta-wrap > div.post-meta > p > small
在内网中免 StosVPN 使用 SideStore div.d-flex > div.post-wrap > h1.post-title > a
05-19 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
2 标签 div.post-meta-wrap > div.post-meta > p > small
从零开始实现 Nix 对数函数库 div.d-flex > div.post-wrap > h1.post-title > a
04-06 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
4 标签 div.post-meta-wrap > div.post-meta > p > small
$100，DIY 搭建合法的 LTE 网络 div.d-flex > div.post-wrap > h1.post-title > a
02-10 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
5 标签 div.post-meta-wrap > div.post-meta > p > small
用 Nix 编译自定义 Android 内核 div.d-flex > div.post-wrap > h1.post-title > a
04-20 div.post-meta-wrap > div.post-meta > p > small
网站与服务端 div.post-meta-wrap > div.post-meta > p > small
2 标签 div.post-meta-wrap > div.post-meta > p > small
使用 Astro.js 重构我的博客 div.d-flex > div.post-wrap > h1.post-title > a
12-16 div.post-meta-wrap > div.post-meta > p > small
计算机与客户端 div.post-meta-wrap > div.post-meta > p > small
1 标签 div.post-meta-wrap > div.post-meta > p > small
NixOS 系列（五）：制作小内存 VPS 的 DD 磁盘镜像 div.d-flex > div.post-wrap > h1.post-title > a
20 div#container > footer.clearfix > div.page-navigator > a.page-number

These are opportunities to improve the legibility of your content.

Best practices

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html html

These items highlight common accessibility best practices.

○Interactive controls are keyboard focusable
○Interactive elements indicate their purpose and state
○The page has a logical tab order
○Visual order on the page follows DOM order
○User focus is not accidentally trapped in a region
○The user's focus is directed to new content added to the page
○HTML5 landmark elements are used to improve navigation
○Offscreen content is hidden from assistive technology
○Custom controls have associated labels
○Custom controls have ARIA roles
●`[aria-*]` attributes match their roles
●`[aria-hidden="true"]` is not present on the document `<body>`
●`[aria-*]` attributes have valid values
●`[aria-*]` attributes are valid and not misspelled
●Buttons have an accessible name
●Image elements have `[alt]` attributes
●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
●ARIA attributes are used as specified for the element's role
●Elements use only permitted ARIA attributes
●Document has a `<title>` element
●`<html>` element has a `[lang]` attribute
●`<html>` element has a valid value for its `[lang]` attribute
●Links have a discernible name
●Touch targets have sufficient size and spacing.
●Heading elements appear in a sequentially-descending order
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Deprecated ARIA roles were not used
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○`[aria-hidden="true"]` elements do not contain focusable descendents
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○`[role]`s have all required `[aria-*]` attributes
○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
○`[role]`s are contained by their required parent element
○`[role]` values are valid
○Elements with the `role=text` attribute do not have focusable descendents.
○ARIA toggle fields have accessible names
○ARIA `tooltip` elements have accessible names
○ARIA `treeitem` elements have accessible names
○The page contains a heading, skip link, or landmark region
○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
○Definition list items are wrapped in `<dl>` elements
○ARIA IDs are unique
○No form fields have multiple labels
○`<frame>` or `<iframe>` elements have a title
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○Form elements have associated labels
○Links are distinguishable without relying on color.
○Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
○List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○Select elements have associated label elements.
○Skip links are focusable.
○No element has a `[tabindex]` value greater than 0
○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
○`[lang]` attributes have a valid value
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○All heading elements contain content.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Identical links have the same purpose.
○Elements with visible text labels have matching accessible names.
○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
○`<td>` elements in a large `<table>` have one or more table headers.
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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