How to Block Kalshi and Polymarket on Windows: What a Domain Block Can and Cannot Do

GuardianBlock for Windows will be available soon.This guide explains the intended public-launch workflow for an adult who has already decided that a prediction-market website is personally off-limits. The distinction matters: a Custom Block will be a rule for an eligible domain you choose. GuardianBlock will not globally classify Kalshi, Polymarket, or every prediction market through that personal choice.

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A personal no-go decision does not have to settle the legal label for everyone else. It only has to define the website boundary you want help holding.

Start with the website surface you actually use

A domain block starts with a website address, not a company name. For Kalshi's ordinary web surface, that means identifying the official kalshi.com domain you use. Do not turn that one address into a promise about an entire account, app, intermediary, or every way a service could be reached.

Polymarket makes the distinction especially visible. Its current official website-versus-app guide describes the international website at polymarket.com and the U.S. app as separate products with unconnected accounts. If the international website is your no-go surface, polymarket.com is the domain decision. A rule for that website does not cover a phone app simply because the same brand name appears on both.

Use the official website URL or registrable domain for the web product you personally use. Avoid guessing at extra addresses. The objective is to declare your own clear boundary, not to build a public map of a platform's infrastructure or possible routes around a rule.

The intended Custom Blocks workflow

At public launch, the intended Custom Blocks flow will make adding a personal no-go website direct and understandable:

• Open Custom Blocks and paste the official website URL or eligible domain you have chosen.
• Review the normalized preview before confirming. By default, the registrable domain and its subdomains are included, so the scope is visible rather than implied.
• Use the exact-host advanced option only when you intentionally want one hostname instead of the registrable domain and its subdomains. Blocking one path or page inside a site is not part of the MVP.
• Confirm the addition. At launch, adding or strengthening protection will not require keyholder approval.
• Tell your keyholder what boundary you chose and what kind of support you want if you later ask to weaken it.

The preview is important. “This website and its subdomains” is a different decision from “this exact hostname.” Neither means “everything operated by this company.” The useful question is not whether the rule sounds broad; it is whether the preview matches the website boundary you meant to set.

The intended Custom Blocks model will not be browsing surveillance. The declared domain and whether the block is active will be part of the accountability decision. Your browsing history, searches, and keystrokes will not be turned into a feed for the keyholder.

Make weakening deliberate

At launch, the intended asymmetry will be simple: you will be able to add a Custom Block yourself, but pausing or removing it will be a keyholder-approved change. The keyholder will sign in to their own account and explicitly approve or deny the request. They will not get a reusable unlock password, and they will not remotely operate or remove software from your computer.

That pause-or-removal decision should not be confused with turning all protection off. The launch product will keep whole-protection deactivation in its own supported request, approval, cooling-off, signed-authorization, and local-uninstall sequence. A reviewed recovery path will also cover an unavailable or abusive keyholder, account loss, and related safety cases. The point is accountability with an exit path—not permanent control by another person.

Before you add the rule, agree on a useful response to a future removal request. A keyholder can ask what changed, remind you why you set the boundary, and help you wait out an impulsive moment. They are not a clinician or a remote administrator, and approval is not a substitute for a real conversation.

What a domain block can—and cannot—cover

At public launch, GuardianBlock is intended for an eligible enrolled personal, unmanaged Windows 11 Home or Pro x64 PC. The public-launch browser scope is Chrome, Edge, and Firefox, with browser-specific private-browsing differences and other limitations; read the current browser support page before relying on the boundary.

• The launch feature will be website-domain friction. It will not close the platform account, cancel open positions, withdraw funds, or control deposits and payments.
• It will not cover phones or native apps, other computers or devices, unsupported or portable browsers, embedded browsing surfaces, or software outside the named browser scope.
• It will apply to the eligible domain scope you confirm. It will not silently extend to unlisted domains or every route by which a service might be reached.
• It will be a personal boundary, not a legal finding that every contract on a platform is gambling or a product rule placing the entire brand in GuardianBlock's compiled list.
• It is intended to add voluntary friction and accountability. It will not be treatment, legal advice, or financial advice, and it will not guarantee an outcome against trading, gambling, relapse, or harm.

Those limits are not fine print. They determine whether this tool matches the problem you are trying to solve. Read GuardianBlock's full limitations for the supported exit, recovery, local-administrator, browser, and device boundaries.

Use more than one layer when the problem crosses layers

A domain rule and a platform control do different jobs. Kalshi's current help materials describe several account-level tools. Its Responsible Trading Hub introduces the settings, while the linked pages explain a trading break, a personalized funding cap, and voluntary self-exclusion. Read each tool's duration, open-position rules, and stated scope before choosing it. The existence of those tools does not prove an outcome, but it does mean a website block need not carry the whole job by itself.

Account decisions are another layer. Polymarket's international help material says account deletion requires positions to be closed and funds withdrawn first, and that on-chain transaction history remains. That is exactly why blocking a website and closing an account should not be described as the same action.

Depending on your situation, a fuller plan may combine the strongest suitable platform control, the website boundary, a bank or payment control you choose, and support from someone you trust. If gambling or trading is causing financial or mental-health harm, seek qualified local help; software is not crisis support or treatment.

Set the boundary you actually mean

If your question is whether a Windows website-domain rule can add friction between you and a site you have chosen to avoid, the intended answer is yes—within the domain, device, and browser limits above. If your question is whether one domain rule closes every product, app, account, payment route, and device associated with a brand, the answer is no.

For the surrounding debate, read our separate explainers on Kalshi's contested legal classification, the young-adult prediction-market protection gap, and choosing when trading becomes a personal no-go. This guide stays narrower: choose the official web surface, review exactly what the domain rule will match, and use other layers for the things a website rule cannot do.