Cookies

This site sets one cookie, and a second one only if you sign in — which almost nobody does, because there is no way to sign up. Both are there to make the site work, both hold a random string rather than anything about you, and the first is gone within a day.

The cookies

• __Host-cv_sid — strictly necessary. A random 24-character string, generated on your first request. It does two jobs, both of them about telling one visitor from another: the file you download is the one you uploaded and nobody else can fetch it by guessing, and the daily fair-use limits are counted one browser at a time instead of one internet connection at a time — so somebody else on the same WiFi cannot use up your conversions. It is not an identity and it is not linked to one — for almost everyone there is no account on this site to link it to.
  It is HttpOnly, so no script on the page can read it; Secure, so it only ever travels over HTTPS; and SameSite=Lax, so another site cannot make your browser send it. It lasts 24 hours and is not renewed in the background.
• __Host-cv_auth — strictly necessary, and only if you sign in. A small number of private accounts exist for people the site owner handed credentials to. There is no way to sign up for one, so if you have not been given an account you will never receive this cookie at all. If you do sign in, it holds a random string that says which sign-in session you are — the server keeps only a one-way hash of it, never the value in your browser.
  It is HttpOnly, Secure and SameSite=Lax for the same reasons as above. It lasts 30 days, or until the account it belongs to expires — whichever comes first — and signing out deletes it on both ends immediately.

Not a cookie, but it is in your browser

• convert-theme — whether you picked light or dark. It lives in your browser's local storage, is never attached to a request and never reaches the server, which is exactly why the setting is per-device rather than following you around.

Cloudflare's cookies

The site sits behind Cloudflare, which carries the traffic and screens out automated abuse. That screening can set its own cookies — typically a short-lived bot-management cookie, and a clearance cookie if a check was actually shown to you. They belong to Cloudflare rather than to this site, they are security measures rather than advertising, and there is no version of this site that can turn them off while still being reachable. Cloudflare documents them on their own site.

Getting rid of them

Any browser will let you clear cookies and site data for a single site, and everything above disappears with it. Nothing is stored anywhere else in your browser, so there is no second place to check.

You can also block cookies for this site entirely — the pages will still load and you can still read everything. Conversions are what stop working: without __Host-cv_sid the server cannot tell that an upload is yours, so it refuses to hand the result back. That refusal is the cookie doing its job, not a bug.

If this page changes

It gets rewritten here and the date below changes. If a cookie is ever added, it will be listed here before it ships.

Last updated 27 August 2026. See also the privacy policy.