The easiest way to connect to Polkadot, Kusama, and Substrate-based chains.

What is Substrate Connect?

A fast, secure, and decentralized way to interact with Polkadot, Kusama, and their parachains right in the browser, Substrate Connect helps you build better end-user experiences for Web3 apps.

Substrate Technology

Light Client Based

Light clients allow you to interact with a blockchain in a less resource-intensive way than running a full node. Because they can quickly sync with a blockchain and run locally in browsers and on mobile and IoT devices, light clients are set to power the future of decentralized applications.

Effortless Connectivity

Running a full node requires a lot of knowledge, effort, and resources, and connecting to remote third-party nodes can be insecure and unreliable. Substrate Connect is the most convenient way to securely and trustlessly connect your app to any Substrate-based chain.

More on light clients

The Browser Extension

The Substrate Connect Browser Extension is using Substrate Connect and Smoldot light client node modules and upon browser initiation updates and synchronizes in the well known substrate chain specs (Polkadot, Kusama, Rococo, Westend), keeping them to the latest state inside the extension, for faster chain sync. When a dApp (e.g. PolkadotJS/apps) that integrates Substrate Connect starts in a browser's tab, it then receives the latest specs from the Extension instead of wrap-synching from the last imported inside the dApp; At the same time, the dApp will appear inside the Extension as "connected" - meaning that it is using the Extension's bootnodes and specs; You can download and Firefox extensions below or find more information on the Github repo.

Developer Docs

Supported Networks



Scalable sharded chain and the first protocol that provides a secure environment for cross-chain composability.



A network built as a risk-taking, fast-moving ‘canary in the coal mine’ for its cousin Polkadot.




Testing environment for Polkadot and Kusama deployments and processes.




Testnet designed for parachains and related technologies: Cumulus and HRMP.