SEOチェッカー
Powered by Semrush Site Audit
Run an SEO audit of your website in seconds. Find technical and on-page SEO issues across your site and get a clear report with what to fix first.
Need more than a free SEO check? Try Site Audit.
How to Use the Free SEO Checker
1
上のフィールドにドメインまたはウェブサイトのURLを入力します2
Click “Analyze Website” to run SEO checks on your site3
Review the SEO report and start fixing critical issues
What Is Semrush’s SEO Checker?
Semrush’s SEO Checker is a free SEO audit tool that scans your website and finds critical SEO issues that could limit your search performance.
The SEO Checker returns an overall SEO score, a prioritized to-do list, and a detailed report that shows both the elements that passed inspection and those that need attention.
The SEO audit analyzes meta tags, headings, keywords, backlinks, page speed, mobile friendliness, Core Web Vitals, social signals, and more.
Improvements to these elements help search engines and AI search platforms better understand, trust, and surface your content when answering users’ questions.
Use the insights to implement high-impact fixes first and track quick wins.
Turn Your SEO Check Into a Full Site Audit
For a deeper, site-wide SEO analysis, upgrade to Semrush’s Site Audit tool. Site Audit crawls your entire site, checks for hundreds of technical and on-page issues, tracks progress over time, and lets you schedule automatic audits.
The free SEO Checker provides a quick snapshot of your SEO health, while Site Audit provides a full roadmap for long-term SEO success.
Why Check Your Website’s SEO?
You should check your website’s SEO to understand how well it’s positioned to perform in Google search, identify issues that may be holding it back, and learn exactly how to fix them to improve your rankings and drive more traffic.
As search evolves toward more AI-driven results and answer experiences, a healthy, well-structured site also increases the chances that your pages can be used, cited, or referenced by AI systems when they generate responses.
An SEO audit reveals hidden problems like missing titles, slow pages, and indexing issues. Fixing these problems helps Google and AI search platforms find your pages and keeps visitors engaged.
Regular audits also confirm what you’re doing right. Strong scores for speed, on-page SEO, off-page SEO, mobile friendliness, and social visibility mean your strategy is working.
If you’re new to SEO, use the report as a learning tool. Start by fixing high-priority technical errors. Then optimize your page titles, descriptions, and headings. Finally, follow step-by-step recommendations to improve speed and mobile scores.
Repeating this process regularly helps you measure progress, refine your SEO strategy, and attract more qualified traffic. Upgrading to Semrush’s Site Audit tool allows you to schedule regular, automated audits and stay apprised of your SEO health.
Worried your website has issues you’re not seeing?
サイト診断を試すGo beyond a one-off check and feel confident you’re fixing what matters most:
Full-Site SEO and Visibility Scans
Crawl your entire site to uncover issues that can limit search visibility.
Prioritized Fixes for Faster Results
Focus on the highest-impact issues with clear priorities based on severity.
Regular Audits and Progress Reports
Run recurring audits and track improvements over time.
Actionable Guidance for Teams
Turn issues into a backlog for dev and content teams with specific fixes.
当社のSEOチェッカーは何を分析しますか？
Our free SEO Checker analyzes on-page, off-page, technical, and performance factors to give you a complete view of your site’s SEO health.
- On-page SEO: We check SEO titles, meta descriptions, headings, keywords, and content to confirm each page is optimized according to best practices.
- Off-page signals: We review backlinks, referring domains, and authority scores to assess your site’s authority and trust in the eyes of search engines.
- Technical SEO: We test crawlability, indexability, status codes, robots directives, sitemap coverage, canonical tags, and structured data so nothing blocks search engines and AI platforms from finding and reading your content.
- Site performance: We analyze page loading speed, mobile friendliness, and Core Web Vitals to ensure a fast, user-friendly experience.
- Social media visibility: We check to ensure you’re leveraging social media to reach your target audience and build brand awareness and authority.
After the scan, you’ll receive an overall SEO score as well as a list of recommendations. Each item includes clear instructions on what to fix and how to fix it, so you can improve rankings with confidence.
サイト診断レポートの使い方
Fix critical SEO issues
クロールブロック、インデックス登録の問題、その他の優先度の高い問題を解決し、検索エンジンがすべてのページを見つけてクロールし、インデックスできるようにします。サイトの速度とパフォーマンスを向上させる
読み込み時間とユーザー体験を改善するため、レポートのページ速度に関するヒントに従い、画像の圧縮、コードの効率化、キャッシュの有効化などを行いましょう。Optimize meta tags and on-page SEO elements
タイトル、メタディスクリプション、見出し、代替テキストを更新し、ベストプラクティスに沿わせてクリック率を改善しましょう。キーワードとコンテンツの機会を特定する
Use the keyword ranking reports to create fresh pages or expand thin content that can capture additional traffic and better match the kinds of questions people ask in both search engines and AI search platforms.オフページSEOを強化する
被リンクのインサイトを確認し、有害なリンクを削除し、権威性を高めるために価値の高いサイトを対象にアウトリーチを行いましょう。SEOの取り組みを検証
High scores and very few issues confirm that your current optimization efforts are working, giving you confidence to stay the course.SEOの知識を高める
分析した要素と特定された問題を学習ロードマップとして活用しましょう。これらのトピックを調査し、ベストプラクティスを実践して専門性を深めてください。時間の経過とともに進捗を追跡する
各回の修正後にSEO診断を再実行して、SEOスコアの上昇を確認し、サイトを成功に向けて最適化された状態を維持しましょう。
ウェブサイト SEO チェッカーから最も恩恵を受けるのは誰ですか？
The following groups will benefit most from using Semrush’s free SEO checker:
- Beginners and Small Business Owners: Get a quick, plain-language assessment of your website. The free SEO report highlights issues, explains why they're important, and provides recommendations for how to fix them. No advanced SEO knowledge is required.
- Intermediate SEOs and Marketers: Validate existing optimization efforts and uncover overlooked gaps. The SEO audit report offers a comprehensive, prioritized checklist, letting you optimize your SEO efforts to improve your strategy and demonstrate results to stakeholders.
- Agencies and In-House SEO Teams: Run consistent audits across multiple sites or sections, prioritize work for developers and content teams, and use shareable reports to prove impact to clients and internal stakeholders.
Think something might be wrong with your website?
Semrush Oneを試すUpgrade to Semrush One to turn that hunch into clear answers and specific fixes:
Comprehensive SEO Checks
Run 140+ technical and on-page checks to find issues that can limit search visibility.
AI Search Health Monitoring
Spot issues that can reduce your visibility in LLMs and AI-driven results.
Site-Wide Reporting
Track site scans, rankings, and AI visibility so you can monitor changes over time.
Clear Priorities and Next Steps
Get clear explanations, fix-first priorities, and practical recommendations.
What Issues Will Our SEO Audit Check For?
メタタグとスニペット
欠落している、または不適切に書かれたタイトルやディスクリプションは検索エンジンを混乱させ、クリック率を低下させます。短すぎる、長すぎる、またはインデックス化がブロックされているタグにフラグを付けます。コンテンツの深度とキーワードの使用
内容が薄いページや重複コンテンツは順位が上がりにくい。監査でテキスト量の少ないページを特定し、拡充または統合を検討できます。見出しとページ構造
順序の乱れたH1〜H3タグ、最適化されていない見出し構造、複雑なURLは、クロールを困難にします。見出しの欠落、URLの問題、カノニカルの問題を指摘します。テクニカルSEO
サーバーの応答が遅いこと、HTTPS の混在、サイズが大きすぎる HTML ファイルは可視性を損ないます。レポートは、修正が必要なステータスコードのエラーやその他のサーバーの問題を一覧します。ページ速度とコアウェブバイタル
Large images, render-blocking scripts, and heavy resources slow your site. We surface the performance issues so you can optimize for faster load times and better user experience.モバイルユーザビリティ
Text that's too small, tap targets that are too close, and content that's wider than the screen push visitors away. The audit highlights mobile issues so you can meet Google's mobile-friendly standards.インデックス登録とクロールアクセス
Robots.txt のブロック、noindex タグ、孤立ページは、検索エンジンがコンテンツを見つけられなくします。取り除けるよう、あらゆる障害を一覧にします。被リンクと信頼性シグナル
弱い、またはスパムが多いリンクプロフィールは権威性を低下させます。監査では被リンク比較、nofollowの分布に関する問題、ソーシャルシェアの可視性を示し、オフページSEOを強化できるようにします。
Why Choose Semrush’s SEO Checker?
You should choose Semrush’s SEO checker over other SEO checkers because it combines a more in-depth audit with practical, plain-language recommendations you can act on right away.
The audit reviews on-page, off-page, technical, social, and page performance factors in one scan and provides actionable recommendations for how to fix any issues identified in the report.
This website analysis tool also uses Semrush’s extensive keyword and backlink databases for precise insights, and explains every issue in plain language so both beginners and pros can act with confidence.
You can run up to three checks a day for free, or upgrade to Semrush’s Site Audit to access deeper scans, more SEO checks, and even more critical insights.
What Can You Achieve with Semrush’s Site Audit?
You can achieve better search visibility, steady organic traffic growth, and improvements in real business outcomes like sign ups, leads, and sales with Semrush’s Site Audit.
Regular audits help you move from one-off checks to ongoing improvements that actually show up in your KPIs.
With Site Audit, you can:
- Ensure your most important pages are discoverable and visible for the searches that drive customers
- Remove technical issues that slow pages down and hurt sign ups, conversions, and checkouts
- Make your content easier for search engines and AI platforms to understand so it can rank for more relevant queries
- Turn issues into a clear, prioritized backlog for dev and content teams so fixes get implemented faster
- Show proof that your SEO work is improving website health, visibility, and business outcomes over time
よくあるご質問
Is the SEO Checker Free to Use?
What’s the Difference Between the Free SEO Checker and Semrush’s Site Audit?
How Often Should I Run an SEO Audit on My Website?
Will Running a Website Audit Affect My Rankings?
Can Semrush’s SEO Checker Help with AI Search Visibility?
Not sure how to turn SEO checks into real progress?
サイト診断を試すUpgrade to Site Audit to turn your findings into a focused improvement plan you can actually use:
Prioritized Tasks and Worklists
Get a ranked list of tasks so you always know what to tackle next.
Issues Grouped for Easy Assignment
See issues grouped by type so you can quickly assign work to dev or content teams.
Trend Reports and Progress Tracking
Track site health and issue counts over time to see how fixes change your results.
Recurring Audits to Stay on Track
Run scheduled crawls to catch new issues early and maintain previous improvements.