Historical Page Comparison
Free, no signup. Compare one bounded Common Crawl capture with the current public page. Coverage is sampled evidence—not proof of every version that existed.
Checks run from our server; we fetch the URL you enter and don't keep the results. The exact URL is sent in a POST body to this site, then used for bounded Common Crawl index/WARC lookup and a safe current-page fetch. Results may be cached; raw archived HTML is not returned. Anonymous run-level outcome counters may be used for aggregate research; URLs, domains, IPs, and identifiers are never included, and no statistic is released below 100 runs.
Site passport Local context for this saved site
Local data
Saved targets, named lists, and recent check summaries remain only in this browser.
Observed page signals
Bounded text changes
How to use it
- Enter one exact public HTTP(S) page URL.
- Optionally choose a before date to prefer an older capture.
- Run the comparison and verify the capture timestamp and crawl index.
- Review changed signals and excerpts. A difference is a review prompt, not an automatic SEO defect.
Example result
A bounded comparison can show a capture timestamp and crawl index alongside a changed title, canonical, or structured-data type. It reports only the selected capture and current raw HTML; a missing capture or a difference is evidence to review, not a complete version history or an automatic SEO defect.
How it works
The service selects one date-relevant Common Crawl index record, reads one bounded WARC byte range, and fetches the current public page through the guarded endpoint. It extracts comparable raw-HTML facts and capped text excerpts; it does not replay archived JavaScript or subresources.
What it checks
The result compares the title, description, H1, word count, canonical URLHow search engines pick one canonical URL among duplicates and consolidate signals onto it., robots directivesThe robots meta tag is an HTML element in a page's head — <meta name="robots" content="noindex"> — that tells search engines how to index and serve that page. It's crawl-then-obey: a page blocked in robots.txt is never fetched, so the tag is never seen., and JSON-LDJSON-LD (JavaScript Object Notation for Linked Data) is a script-based structured data format, typically paired with the schema.org vocabulary to describe page content for search engines and AI systems. Google recommends it over Microdata and RDFa because it's the easiest format to implement and maintain at scale — but all three work, and structured data isn't a ranking signal. types. Similarity and excerpts use normalized extracted text from bounded raw HTML; they are not a rendered-page replay.
Common Crawl attribution and limitations
Historical capture data comes from Common Crawl; this site is not affiliated with it. Common Crawl samples the web, so captures can be absent, incomplete, truncated, or represented by revisit records without a payload. The tool queries only a few date-relevant crawl indexes and never promises lifetime coverage.
The comparison shows derived observations and small bounded excerpts—not a license to republish a third party’s archived page. Review the Common Crawl Terms of Use and any rights or terms that apply to the originating page before commercial reuse.
Frequently asked questions
What does the tool compare?
It compares one exact URL’s selected Common Crawl capture with the current public page: title, H1, meta description, canonical, robots directives, word count, structured-data types, bounded text similarity, and capped added/removed excerpts. Capture and current HTTP statuses are shown separately as source observations, not as a status-history comparison.
Does a missing capture mean the page never existed?
No. Common Crawl samples the web and does not capture every URL on every crawl. Missing, incomplete, revisit-only, and truncated records are reported as coverage limits rather than converted into a pass or failure.
Can I view or download the complete archived page?
No. The service retrieves one exact WARC byte range and returns only derived facts and bounded text excerpts. It does not provide a full-page archive viewer, execute archived JavaScript, or load archived subresources.
Can I use the result commercially?
This tool reports derived observations and does not grant rights in third-party archived content. Review Common Crawl’s current terms and the originating site’s rights before relying on archived material in a commercial product.
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ツールについて
Common Crawlの制限付きキャプチャ1件と現在のページを比較し、メタデータ、canonical、robotsディレクティブ、構造化データ型、語数、抽出テキストの変更を確認します。取得元HTTPステータスは別の観測値として扱います。
無料・登録不要。公開HTTP(S)ページの正確なURLを1つ入力し、必要なら以前の日付を選んで古いキャプチャを優先します。比較を実行してキャプチャ日時とクロールインデックスを確認し、差分は自動的なSEO欠陥ではなくレビューの手掛かりとして扱います。
機能
- 選択したキャプチャと現在ページの比較
- タイトル、説明、canonical、robotsの差分
- 構造化データ型と抽出語数の比較
- 変更箇所と取得状態を確認できるレポート
仕組み
選択したCommon Crawlキャプチャと現在のページを制限付きで取得し、HTTPステータス、タイトル、説明、canonical、robots、見出し、構造化データ型、語数、抽出テキストを同じ形式へ正規化します。隣接する値を比較し、変更、欠落、取得失敗を分けて表示します。
制限事項
- Common Crawlのキャプチャはすべての版や資産を保持するとは限らず、比較は取得できたHTMLに限られます。差分だけで原因、意図、SEO上の欠陥を証明することはできません。
- JavaScript、サブリソース、認証ページは完全に再現されない場合があります。現在ページと過去キャプチャの取得時点も異なるため、観測できない期間を推測しません。
よくある質問
どのページを比較できますか？
公開HTTP(S) URLを1つ指定できます。アクセス制限、認証、キャプチャ欠落があるページは比較できない場合があります。
差分は自動的なSEO欠陥ですか？
いいえ。差分は調査の手掛かりです。意図した変更か、現在のcanonical・robots・コンテンツと整合するかを確認してください。
Common Crawlのキャプチャにない変更を検出できますか？
いいえ。保存された1件のキャプチャと現在の取得結果から観測できる違いだけを表示します。