Audit Result

Found 10 characters. Keep title between 30 and 60 characters.

Fix: Add a unique <title> tag describing the main page intent in 30-60 characters.

Missing meta description.

Fix: Add <meta name="description" content="..."> in <head> with a clear page summary.

Canonical link not found.

Fix: Add <link rel="canonical" href="https://example.com/page"> to avoid duplicate URL ambiguity.

Favicon found and reachable: img/favicon.ico (HTTP 200).

Viewport configured: width=device-width, initial-scale=1.0

Language declared as "jp".

Found 6 H1 tags.

Fix: Use a single, descriptive <h1> that states the primary purpose of the page.

Detected 2 heading level jumps.

• • Skipped from h1 to h5: "製品情報" -> "テーブルゲーム".
• • Skipped from h1 to h3: "お問い合わせ" -> "お問い合わせに関する個人情報の取り扱いについて".

Fix: Follow semantic order (h1 -> h2 -> h3) and avoid skipping heading levels.

9 of 9 images are missing alt text.

Fix: Add meaningful alt attributes to all informative images for accessibility and image SEO.

Page is served over HTTPS.

2 HTTPS hardening issues detected.

• • Missing Strict-Transport-Security header.
• • Could not probe the HTTP version of this page.

Fix: Set Strict-Transport-Security with a long max-age, add includeSubDomains, and redirect all HTTP requests to HTTPS.

Missing: strict-transport-security, content-security-policy, x-frame-options, x-content-type-options, referrer-policy.

Fix: Add the missing security headers at your reverse proxy or application layer.

Content-Security-Policy header is missing.

• • Missing Content-Security-Policy header.

Fix: Define a restrictive Content-Security-Policy and avoid unsafe directives such as unsafe-inline and unsafe-eval.

No first-party cookies were set during the initial page load.

Server response headers do not expose version tokens.

Domain does not appear to be behind Cloudflare.

Loaded in 2.38s (perceived).

Fix: Reduce payload size, cache static assets, and remove non-critical JS from initial load.

1 scripts and 5 styles may block rendering.

• • script: https://diagram.co.jp/js/delighters.js
• • style: https://fonts.googleapis.com/css?family=Open+Sans:Lato:300,400,700,300italic,400italic|Raleway:400,300,700
• • style: https://diagram.co.jp/css/style.css
• • style: https://diagram.co.jp/lib/icomoon/icomoon.css
• • style: https://diagram.co.jp/lib/bootstrap/css/bootstrap.css
• • style: https://diagram.co.jp/css/dgm.css

Fix: Defer non-critical scripts and inline critical CSS to improve first paint speed.

1 text resources look uncompressed.

• • https://diagram.co.jp/js/main.js (application/javascript)

Fix: Enable Brotli or Gzip compression for HTML, CSS, JS, and JSON responses.

robots.txt missing or inaccessible (404).

Fix: Create a robots.txt file at https://diagram.co.jp/robots.txt and allow intended crawlers.

Sitemap missing or inaccessible at https://diagram.co.jp/sitemap.xml (404).

Fix: Publish a sitemap.xml and reference it in robots.txt with: Sitemap: https://diagram.co.jp/sitemap.xml

No robots meta tag defined.

Fix: Add <meta name="robots" content="index,follow"> (or the intended directive) in <head>.

5 of 5 controls are missing labels.

• • input[type="name"]#contact-name.form-name.form-control (name)
• • input[type="comname"]#contact-comname.form-control (comname)
• • input[type="tel"]#contact-tel.form-control (tel)
• • input[type="email"]#contact-email.form-mail.form-control (email)
• • textarea#contact-message.form-control (message)

Fix: Associate each form control with a visible label, aria-label, or aria-labelledby.

Missing landmarks: nav, footer.

Fix: Use semantic regions (<header>, <nav>, <main>, <footer>) for navigation and assistive tech.

4 interactive elements appear smaller than 48px.

• • a.btn.btn-dgm (詳細) - 48x30px
• • a.btn.btn-dgm (詳細) - 48x30px
• • a.btn.btn-dgm (詳細) - 48x30px
• • a.btn.btn-dgm (採用情報はこちら) - 173x38px

Fix: Increase target size to at least 48x48 CSS pixels for touch interactions.

Missing og:title or og:description.

Fix: Add og:title and og:description tags to control social preview text.

og:image is missing.

Fix: Add <meta property="og:image" content="https://..."> with a high-quality share image.

twitter:card is missing.

Fix: Add <meta name="twitter:card" content="summary_large_image"> for better previews on X.

No JSON-LD schema scripts found.

Fix: Add JSON-LD structured data matching your page type (Organization, Article, Product, etc.).

Manifest or Apple touch icon is missing.

Fix: Link your web app manifest and apple-touch-icon for improved install/share experiences.

5 social preview quality issues detected.

• • ISSUE: og:url should be an absolute URL.
• • ISSUE: og:title should typically be between 10 and 70 characters.
• • ISSUE: og:description should typically be between 50 and 200 characters.
• • ISSUE: Use an absolute URL for og:image or twitter:image.
• • ISSUE: twitter:card is missing.
• • GUIDELINE: Optimal og:title length: 40-60 characters (acceptable: 10-70).
• • GUIDELINE: Optimal og:description length: 110-160 characters (acceptable: 50-200).
• • GUIDELINE: Optimal preview image size: 1200x630 pixels.
• • GUIDELINE: Optimal preview image aspect ratio: 1.91:1.
• • GUIDELINE: Optimal preview image file size: under 5 MB.
• • GUIDELINE: Recommended twitter:card: summary_large_image.

Fix: Use absolute OG/Twitter URLs, keep metadata lengths in recommended ranges, and provide a preview image near 1200x630 under 5MB.

Checked 3 links. No broken internal links found.

No broken external links found in checked URLs.

All 15 links use non-empty href values.

Largest Contentful Paint: 3.39s.

Fix: Improve LCP by optimizing above-the-fold media, reducing server latency, and inlining critical CSS.

Cumulative Layout Shift: 0.000.

Total Blocking Time estimate: 22ms.

No failed CSS/JS/image/font/media requests detected.

No console/page runtime errors detected during audit.