Cookie Policy
VERSION 1.3 · EFFECTIVE SEPTEMBER 10, 2026 · DRAFT PENDING COUNSEL REVIEW · QUANTGPT LLC, A FLORIDA LIMITED LIABILITY COMPANY
This policy explains the cookies and similar technologies used on quantgpt.co, its subdomains, and the QuantGPT terminal. It is part of our Privacy Policy.
// THE ONE-LINE VERSION
We set only the cookies needed to keep you logged in and to keep the site safe. We do not use advertising cookies, and we do not track you across other websites.
// WHAT A COOKIE IS
A cookie is a small text file a website stores in your browser. Strictly necessary cookies make a site work, for example by remembering that you are logged in. Other kinds can track browsing across sites for advertising. We use only the first kind.
// THE COOKIES WE SET
| Cookie | Set by | Purpose | Lifetime | Type |
|---|---|---|---|---|
session | QuantGPT terminal | Keeps you signed in to the terminal and ties your requests to your account. Signed so it cannot be forged. Marked Secure and HttpOnly. | Browser session, or up to 30 days if you stay signed in | Strictly necessary |
qg_gate | quantgpt.co | Remembers that you unlocked a password-protected area of the site. Contains a hash, not the password. | Up to 30 days | Strictly necessary |
__cf_bm and related | Cloudflare | Distinguishes real visitors from automated traffic in front of the terminal, so scrapers and brute-force attempts are challenged. | Up to 30 minutes | Strictly necessary (security) |
_rdt_uuid | Reddit, on quantgpt.co only | Advertising measurement: tells Reddit that a visit or a waitlist signup followed one of our Reddit ads, so we can see which ads work. Set only for visitors in the United States who have not turned on Global Privacy Control or Do Not Track; never on the terminal. | 90 days | Advertising (optional) |
__stripe_mid, __stripe_sid | Stripe, on checkout and billing pages | Fraud detection and session continuity for payment. Governed by Stripe's policy. | Session to 1 year | Strictly necessary (payment) |
One advertising pixel runs on the marketing site and nowhere else: the Reddit Pixel, described under Advertising Measurement below. No other advertising cookies, social media pixels, or cross-site tracking identifiers are set on our pages, and we do not allow other third parties to set them.
// LOCAL STORAGE
Some pages use your browser's local storage to remember interface preferences, for example a saved workspace layout or a dismissed notice. That data stays on your device, is not sent to us unless it is part of a workspace you save to your account, and can be cleared from your browser settings.
// ADVERTISING MEASUREMENT
When we advertise on Reddit, the Reddit Pixel on quantgpt.co records that a visit or a waitlist signup followed one of our ads. It sets the _rdt_uuid cookie and sends Reddit the page visited, the event (a page visit or a waitlist signup), and the technical details a browser sends with any request. It never runs inside the terminal, it never sees a study or an account, and it is not loaded at all for visitors outside the United States or for anyone whose browser sends the Global Privacy Control or Do Not Track signal. To opt out otherwise, turn on Global Privacy Control in your browser, or use Reddit's own advertising controls at reddit.com/personalization. Reddit's use of the data is governed by Reddit's privacy policy.
// ANALYTICS
On quantgpt.co we use Vercel Web Analytics, which is cookieless and reports aggregate page views without identifying individuals or tracking across sites. If we add analytics, we intend to use a cookieless, privacy-preserving service that reports aggregate page views without identifying individuals and without cross-site tracking, and we will update this policy before it goes live. [UPDATE WHEN PLAUSIBLE OR EQUIVALENT IS DEPLOYED.]
// CONSENT
Every cookie set by the terminal is strictly necessary to provide the service you asked for or to keep it secure, so no consent is needed for those and we do not show a cookie banner. The one optional cookie, Reddit's on the marketing site, is only set for United States visitors, where the law provides an opt-out rather than an opt-in; we honor the Global Privacy Control signal as that opt-out. If we ever introduce cookies that are not strictly necessary, we will ask for your consent first, and you will be able to refuse without losing access to the Service.
// HOW TO CONTROL COOKIES
You can delete or block cookies in your browser settings. If you block the session cookie you will not be able to stay signed in to the terminal, and if you block Stripe's cookies you may not be able to complete checkout. Blocking the Cloudflare cookie may cause you to see a security challenge more often.
// CONTACT
Questions about cookies: desk@quantgpt.co.