Tools /  Cookie & Storage Inspector

Cookie & Storage Inspector

クッキー検査
検証済TESTED
Cookies クッキー
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Only cookies readable by JavaScript appear here. HttpOnly cookies (logins, sessions) are hidden from scripts by design, so an empty list doesn’t mean no cookies exist.

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localStorage ローカルストレージ
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Persists until the site or you clear it. The Remove button deletes the entry for real; these are your own entries on your own device, so no confirmation is asked.

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sessionStorage セッションストレージ
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Lives only as long as this tab. Close the tab and it’s gone on its own; Remove deletes an entry immediately.

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You’re seeing first-party storage only: what this site keeps in your browser. It’s a short list because chekkutooru stores almost nothing; ad-heavy sites can carry dozens of third-party entries. Everything here is read locally and never sent anywhere.

How it works

仕組み

Open the drawer and see what this site keeps in your browser: every JavaScript-readable cookie plus each localStorage and sessionStorage entry, with its size in bytes and a preview of its value. You can delete any storage entry on the spot, since it all sits on your device and belongs to you. The list here is deliberately short, because chekkutooru stores almost nothing; visit an ad-heavy news site with the same developer-tools view and you’ll find dozens. Since storage is per-site and per-browser, only your own machine can show you this inventory.

Why does the cookie list look empty or shorter than expected?

Cookies flagged HttpOnly are hidden from JavaScript on purpose: they carry logins and session IDs, and keeping scripts away from them blunts cookie-theft attacks. Browser developer tools can show them, but no script on the page can. So an empty list here means no script-readable cookies, not necessarily no cookies.

What’s the difference between first-party and third-party storage?

First-party storage belongs to the site in your address bar; third-party cookies are set by other domains embedded in the page (ad networks, analytics, social widgets) and historically let them recognise you across the web. Safari and Firefox block third-party cookies by default and Chrome now isolates them per site, which is why the practice is fading.

localStorage versus sessionStorage: when does each get used?

Both hold simple key-value strings with roughly a 5 MB budget per site. localStorage persists until the site or you delete it, which makes it good for theme choices and drafts. sessionStorage evaporates when the tab closes, so it suits one-visit state like a form in progress. Neither is sent to the server automatically, unlike cookies.

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