Pre-publish Comparison
Free, no signup. Compare a draft HTML export with the current live HTML you supply before approving a release.
Supply both HTML documents
1 MiB maximum per document. Oversized input is rejected in full; it is never silently shortened. Use HTML only—do not paste credentials, access tokens, personal data, or confidential source comments.
Runs entirely in your browser — nothing you paste is uploaded or stored. The tool does not fetch URLs, call AI, use credentials, persist input, or include source HTML in exports. 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.
Sample report
Fabricated draft and live HTML
Regression: the draft removes one live hreflang declaration.
Changed: the title and heading outline differ.
Not evaluated: AI-crawler posture is not observable from the supplied HTML.
How to use it
- Export or view the complete HTML for the draft and current live page.
- Paste both documents or choose two local
.htmlfiles. Inputs over 1 MiB are rejected. - Compare the normalized signal rows. Investigate regressions first, then confirm whether each changed row is intentional.
- Download CSV or JSON rows for a release checklist. The exports omit the supplied source HTML.
Site passport Local context for this saved site
Local data
Saved targets, named lists, and recent check summaries remain only in this browser.
| Signal | Draft | Live | Result |
|---|
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How it works
The parser scopes title, description, canonical, robots, hreflang, and JSON-LD evidence to the document head. Commented tags, script strings, and body-level decoys are ignored. HTML entities are decoded, JSON-LD object keys are normalized structurally, and heading levels plus text are compared as an ordered outline.
Limits
The result covers only the two supplied documents. It does not fetch a live URL, render JavaScript, inspect HTTP headers, read robots.txt, verify hreflang reciprocity, validate schema eligibility, or determine whether a release should proceed. Malformed or unavailable evidence remains not evaluated.
Frequently asked questions
Does this fetch either page?
No. Supply each HTML document by pasting it or choosing a local .html file. Both documents and the comparison stay in this browser; neither page nor its contents are fetched or uploaded. A bounded anonymous usage ping may be sent after a run, but it contains no supplied HTML, URL, domain, IP, or identifier.
What happens when a signal cannot be evaluated?
The row stays not evaluated. A missing or malformed head, malformed JSON-LD, and crawler posture that HTML cannot establish are not treated as matches.
What counts as a regression?
The conservative regression label is reserved for removed observed evidence, removed hreflang declarations, a shorter heading outline or lost H1, and newly restrictive robots or crawler directives. Other differences are labeled changed for human review.
Why is AI-crawler posture not evaluated?
A pasted HTML document does not prove the site robots.txt policy or edge behavior for AI crawlers. The row is retained to make that evidence boundary explicit.
What does an export contain?
Exports contain only the normalized comparison rows and their states. They never include either pasted HTML document.
Feature requests for Prepublish Comparison
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ツールについて
タイトル、説明、canonical、robots、hreflang、見出し構造、構造化データを、下書きHTMLと提示した現在のHTMLでローカル比較します。
公開前に、供給したHTMLの比較結果と保守的な回帰シグナルを確認し、意図した変更をリリース文脈でレビューします。
機能
- ドキュメントヘッドの主要SEOシグナル比較
- 見出しアウトラインと構造化データの比較
- match、changed、regression、not evaluatedの状態
- 正規化した行だけをCSV/JSONでエクスポート
仕組み
パーサーはtitle、description、canonical、robots、hreflang、JSON-LDをhead内に限定し、コメントやscript文字列、bodyの偽タグを無視します。HTMLエンティティをデコードし、JSON-LDのキーを構造的に正規化して、見出しレベルと本文を順序付きアウトラインで比較します。
制限事項
- 2つの入力文書だけを比較し、ライブURL、JavaScript、HTTPヘッダー、robots.txt、hreflang相互性、スキーマ適格性は確認しません。欠損または壊れた証拠は未評価のままで、回帰はランキング、トラフィック、リリース影響の予測ではありません。
よくある質問
このツールはどちらのページも取得しますか?
いいえ。HTMLを貼り付けるかローカルファイルを選び、文書と比較結果をブラウザー内に保持します。ページや内容は取得・アップロードしません。
回帰とは何ですか?
観測された証拠の削除、hreflang宣言の削除、見出しの短縮やH1消失、新たに制限的になったrobotsまたはクローラーディレクティブです。その他の差は人のレビュー用にchangedと表示します。
シグナルを評価できない場合はどうなりますか?
その行はnot evaluatedのままです。欠損または不正なhead、壊れたJSON-LD、HTMLだけでは分からないクローラー方針を一致や合格として扱いません。