Polkadot Web¶

Introduction¶

Polkadot Web is the browser-based Host that loads Polkadot Products from any browser tab — no install required. Served at dot.li, it is the third sibling alongside the Polkadot App and Polkadot Desktop. Its job is the same as theirs: load a Polkadot Product inside a sandbox, mediate everything it touches (signing, chain access, storage, outbound requests) through the Host API.

What makes Web different from Desktop is not the model — it is the delivery. Web runs in a regular browser instead of an installed application, which changes:

• The trust surface: The browser is the runtime.
• The visiting flow: A Product is loaded by navigating to it in a browser tab, not from an installed address bar.
• The upgrade path: Products and the Host itself update on page load, not via an OS installer.

The Product surface a developer targets, including .dot name addressing, the TrUAPI surface, and the per-Product sub-account model, is the same in either Host.

Architecture¶

At a high level, three properties matter to a Product developer building for Web:

• Browser-tab runtime: Polkadot Web is a regular browser page at dot.li. Products are loaded inside it, not as standalone tabs.
• Same sandbox contract as Desktop: A Product running on Web sees the same per-Product account model, the same TrUAPI surface, and the same permission system as a Product running on Desktop. Code that works in Desktop will work on Web, with surface differences called out per-page in this subsection.
• Pairs with the Polkadot App for signing: Like Desktop, Polkadot Web does not hold the user's signing key. A browser session pairs with the user's paired App, and every signed action goes through the App for per-transaction approval.

Visiting and Shield States¶

Two concepts are specific enough to Web to deserve their own pages:

• Visiting a Product: How a .dot name is resolved and a Product is loaded into a browser tab, and how this differs from Desktop's address-bar flow.
• Shield States: The security-indicator UI that surfaces the trust posture of the loaded Product, including bundle verification and Host state.

Host API on Web¶

The TrUAPI surface a Product calls on Web is materially the same as on Desktop. There are a small number of capabilities where the underlying behavior differs because of the browser context (storage, outbound requests, media access), and those are documented at Host API.

On-Chain polkadot.com¶

A Polkadot Product can also serve as the meta-surface that points to other Products: a discovery layer running as a Product itself. The canonical instance of this is On-Chain polkadot.com, which is the on-chain-published presence backing the polkadot.com site.

Upload Journeys¶

Where to Go Next¶