Cookie Policy
VERSION 1.4 · EFFECTIVE SEPTEMBER 22, 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
The terminal sets only the cookies needed to keep you logged in and to keep it safe. The marketing site, quantgpt.co, adds one advertising pixel, Reddit's, and only for visitors in the United States whose browser sends neither Global Privacy Control nor Do Not Track.
// 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. The terminal uses only the first kind; the one exception on the marketing site is described under Advertising Measurement below.
// 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: lets Reddit tell that a visit or a waitlist signup followed one of our Reddit ads, so we can see which ads work. Set by Reddit's script only for visitors in the United States who have not turned on Global Privacy Control or Do Not Track; never on the terminal. Reddit's script may set related _rdt_ cookies under the same conditions. | 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. A Whop attribution pixel is also included in the marketing site's code but is dormant (it has no business id, so it loads nothing and sets nothing); we will list what it sets here before we activate it. 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. The marketing site also keeps these keys:
| Key | Where | Purpose | Lifetime |
|---|---|---|---|
qg_src | Local storage, quantgpt.co | First-touch attribution: the short partner or campaign code from a /go/ link, added to the terminal sign-in link so a signup records where it came from. A Reddit campaign code (starting rd-) is kept only under the Reddit conditions below. | Until you clear it |
qg_rdt_cid | Local storage, quantgpt.co | Advertising measurement: the Reddit click id (rdt_cid) Reddit adds to an ad's link, added to the terminal sign-in link so that a sign-up or purchase can be reported to Reddit (see below). Kept only for United States visitors without Global Privacy Control or Do Not Track; otherwise discarded and cleared. | Until you clear it |
qg_cc | Session storage, quantgpt.co | The two-letter country our server looked up for this visit, so the region check for the Reddit Pixel runs once per tab. No IP address is kept. | Until the tab closes |
// 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 loads only on quantgpt.co, never inside the terminal, and only for visitors our server places in the United States whose browser sends neither the Global Privacy Control nor the Do Not Track signal; for everyone else it is never loaded. When it loads, it sets the _rdt_uuid cookie and sends Reddit a page visit on each page and a "Lead" event when you join the waitlist (not your email), together with the technical details a browser sends with any request, such as your IP address, user agent, and the page address.
Under the same conditions our site stores the Reddit click id as qg_rdt_cid (above) and passes it to the terminal sign-in link. If you then create an account or start a paid plan, our server reports that sign-up or purchase to Reddit's Conversions API with the click id, a SHA-256 hash of your email address, a hash of your account id, the IP address and user agent of the sign-up request, and for a purchase the plan price. Accounts that did not arrive from a Reddit ad are never reported. The Privacy Policy, Section 8, has the full detail.
To opt out, turn on Global Privacy Control (or Do Not Track) in your browser: the pixel will not load and the click id will not be stored or forwarded. You can also clear the cookie and local storage for quantgpt.co, email desk@quantgpt.co, or use Reddit's own advertising controls at reddit.com/settings/privacy. 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 change analytics providers, we will use a cookieless service of the same kind and update this policy before it goes live.
// 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, and the Reddit click id kept in local storage are only set for United States visitors, where the law provides an opt-out rather than an opt-in; we honor the Global Privacy Control and Do Not Track signals 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.