What is Polkadot, and what is it used for?

Polkadot is a blockchain network built so that many separate blockchains can run side by side, share one security system and pass tokens and messages to each other. Its coin, DOT, pays fees, gets staked to keep the network honest and gives holders a vote on how Polkadot changes. It was designed by Ethereum co-founder Gavin Wood and has been running since 2020.

Why build a network of blockchains at all?

A blockchain is a shared ledger that many independent computers keep in sync, so no single company can quietly change it. Its safety comes from those computers and from the money their owners put at stake, which is the core idea behind how cryptocurrency and blockchain work.

That design has two awkward sides, and Polkadot was built around both:

• Each chain is an island. Bitcoin cannot read Ethereum, and Ethereum cannot read Solana. Moving value between them takes an exchange or a bridge.
• Each new chain starts weak. A fresh blockchain has few computers guarding it and little money at stake, so it is cheaper to attack than an established one.

Polkadot's answer is to let new chains plug into one shared set of guards from their first day, and to give them a common language for talking to each other.

Gavin Wood described this design in a 2016 white paper, while he was best known as the co-founder of Ethereum and author of its technical specification. The Web3 Foundation backs the project, and Parity Technologies, a company Wood co-founded, wrote most of the original software.

How Polkadot is put together

Polkadot has three kinds of parts, and most confusion about it disappears once they have names:

• The relay chain. This is the core of the network. Its validators, the computers that check and confirm blocks, make sure everything attached to Polkadot follows the rules. The relay chain does not run apps itself.
• Parachains. These are separate blockchains attached to the relay chain, each built for one job: a trading venue, a game economy, an identity system. The name comes from "parallel chains", because they process their own transactions at the same time.
• Polkadot Hub. This is a chain run by the network itself, and it is where ordinary accounts live. DOT balances, staking, voting, stablecoins and smart contracts all sit there, so most people who "use Polkadot" are actually using the Hub.

What parachains are and how they get their place

A parachain is a full blockchain with its own rules and often its own token, but it does not hire its own guards. Its blocks go to the relay chain, where Polkadot's validators check them. This is called shared security: a parachain launched yesterday is protected by the same validators and the same staked DOT as the rest of the network. Polkadot's own materials now also call parachains "rollups".

Room on the relay chain is limited, so parachains pay for it. Until 2024, projects won long-term slots at auctions, often funded through crowdloans, where DOT holders locked their coins to support a project. Polkadot replaced that system with coretime: a chain buys processing time on the relay chain with DOT, either in 28-day blocks or one block at a time when it needs it. Auctions and crowdloans are gone.

Parachains talk to each other through a shared message format called XCM, short for cross-consensus messaging. Because the same validators check every parachain, a token sent from one to another does not depend on an outside middleman. Reaching chains outside Polkadot, such as Ethereum, is a different story: that still takes a bridge, with the trade-offs explained in how cross-chain bridges work and why they are risky.

What is Polkadot used for?

Polkadot is not one app, and DOT is not the only thing that moves on it. In practice the network is used for a handful of distinct things:

• Holding and sending stablecoins. USDT and USDC are issued directly on Polkadot Hub, so dollar tokens can move between accounts and parachains without a wrapped copy in between.
• Running apps as their own chains. A project that needs its own rules, such as custom fees or a game economy, can launch a parachain instead of competing for space on a crowded general-purpose chain. The parachain keeps its own rules and token, while Polkadot's validators check its blocks.
• Public funding. Polkadot keeps an on-chain treasury that pays for development and community projects, and DOT holders decide by referendum where that money goes.
• Smart contracts on the Hub. Polkadot Hub runs Ethereum-compatible contracts, so a developer can deploy code written in Solidity, Ethereum's main programming language, without rewriting it. These are the self-running programs described in how smart contracts work on a blockchain.

What the DOT coin does

DOT is the Polkadot network's own coin. It has four jobs:

• Paying fees. Every transaction on Polkadot pays a small fee, normally in DOT. Polkadot Hub also accepts fees in some other assets.
• Staking. Holders lock DOT behind validators to secure the network and receive new DOT in return. How that works is in the next section.
• Voting. Under Polkadot's on-chain governance, called OpenGov, any DOT holder can vote on referendums, from software upgrades to treasury spending. When an upgrade passes, the network switches to the new rules without splitting into two chains.
• Buying coretime. Parachains pay for their place on the relay chain in DOT.

The supply rules changed recently. Until March 2026, Polkadot created about 120 million new DOT a year with no ceiling. In September 2025 holders voted to cap the total at 2.1 billion DOT, and on 14 March 2026 yearly issuance fell to about 55 million DOT, with further cuts every two years. A little over 1.7 billion DOT existed by late summer 2026.

How Polkadot staking works

Staking on Polkadot is called nominated proof of stake. The name points to its two roles:

• Validators run the servers that produce and check blocks. Since summer 2026, each validator must lock at least 10,000 DOT of its own, and it can lose part of that stake, which is called being slashed, for misbehaving, for example by signing two conflicting blocks.
• Nominators are DOT holders who back validators they trust. They run nothing themselves: they pick validators, and their DOT adds weight to those validators.

Every validator is a node, a computer running the full network software around the clock. The difference between a node like that and the wallet app on your phone is laid out in what a node in crypto actually does.

The network works in eras of 24 hours. In each era it picks an active set of about 600 validators, ranked by the stake behind them, and pays out rewards for the work they did. Since the end of June 2026, that money reaches people in two ways:

• Nominators share the staking rewards. Everyone whose DOT backs a validator gets a part in proportion to their stake, and the validator no longer takes a commission from it.
• Validators are paid from a separate budget. That budget rewards them for the DOT they lock themselves.

Payouts are not automatic: anyone can trigger them, and rewards nobody claims within 84 eras are lost.

A newcomer has three ways in:

• A nomination pool. You can join one with 1 DOT. The pool picks validators for its members and shares out the rewards.
• Direct nomination. You pick validators yourself, but you need more DOT than the minimum active stake. That minimum is not fixed: it equals the stake of the smallest nominator who still makes the cut, and wallets show the current figure.
• Staking through an exchange. The exchange stakes on your behalf. It is the simplest route, but the exchange holds your coins and sets its own terms and fees.

Getting out has become much faster. Since July 2026, a nominator who stops staking waits about two days for the DOT to unlock, down from 28 days, and nominators can no longer be slashed. Validators still can. A new nomination takes one to two eras, so up to about 48 hours, before it starts earning.

One limit is worth keeping in mind: staking rewards are paid in DOT. The extra coins grow your DOT balance, but they do not protect its value in dollars if the price of DOT falls.

How Polkadot compares with Ethereum

Both networks run smart contracts and both use proof of stake, so the comparison comes up quickly. The real difference is in how each one grows:

• One chain or many. Ethereum is one main chain that all apps share, and it handles growth by pushing traffic to layer-2 networks such as Base, Arbitrum and Optimism. Polkadot was designed from the start as many chains, each checked by the relay chain's own validators.
• Where apps live. On Ethereum, apps are smart contracts on the main chain or on a layer 2. On Polkadot, an app lives either as a contract on Polkadot Hub, which accepts code written for Ethereum, or as a whole parachain with its own rules.
• How the rules change. Ethereum upgrades through developer proposals and coordinated software releases, agreed off-chain. On Polkadot, DOT holders vote on-chain, and an approved upgrade is written into the chain itself, so the network does not need a hard fork to adopt it.
• What it takes to stake. Running an Ethereum validator takes 32 ETH. A Polkadot validator needs 10,000 DOT of its own, while a Polkadot nominator can join a pool with 1 DOT. Ethereum also has pools for smaller amounts.
• How much can exist. ETH has no fixed supply cap. DOT has been capped at 2.1 billion since the September 2025 vote.

Neither design is simply better: Ethereum keeps everything in one place where apps can call each other directly, while Polkadot gives each project its own chain at the cost of more moving parts. For the Ethereum side in the same detail, the mechanics are laid out in how the Ethereum network works and processes ETH payments.

Choosing a Polkadot wallet

A Polkadot wallet holds the keys to your Polkadot account, while the DOT itself is recorded on Polkadot Hub. A standard Polkadot address starts with the digit 1, which makes it easy to tell apart from an Ethereum address starting with 0x.

The main options differ in who holds the keys:

• Wallets built for Polkadot. Nova Wallet and SubWallet work on a phone, and Talisman works as a browser extension. All three keep your keys on your device and let you stake and vote, not just send DOT.
• A hardware wallet. A Ledger device keeps the keys offline and signs transactions through one of those wallets, which suits larger amounts.
• Polkadot Vault. This app turns a spare phone kept permanently offline into a signing device, a free alternative to buying hardware.
• An exchange account. This is the easiest place to start, but the exchange holds the keys, and staking and voting happen on its terms.

Two habits save trouble with any of them:

• Install only from the official listing. Fake copies of wallet websites exist, including a documented phishing copy of Nova's web wallet. Get the app from your phone's app store, where the iOS version is listed as "Nova Polkadot Wallet", or through the link on the wallet's own website, and never type your recovery phrase into a web page.
• Leave 0.01 DOT behind. Every Polkadot account must hold at least 0.01 DOT. An account that drops below that minimum is closed, and the dust left in it is lost.

If you are choosing one wallet for several coins rather than for DOT alone, compare the options by situation in the best crypto wallet for your needs.

The short version

Polkadot is a network of blockchains: the relay chain provides shared security, parachains do specialised jobs, and Polkadot Hub is where accounts, stablecoins, staking and votes live. DOT pays fees, secures the network through staking and gives its holders a say in how Polkadot changes. If you plan to hold DOT, the practical choices are a wallet that keeps your keys and, if you want rewards, a nomination pool or direct nomination.

Questions people ask next

When did Polkadot actually launch?

The first Polkadot block was produced on 26 May 2020, and the network switched to proof of stake that June. DOT transfers were turned on by a holder vote on 18 August 2020. The first parachains went live on 18 December 2021, which completed the original launch plan.

Is Asset Hub the same thing as Polkadot Hub?

Yes. Asset Hub is the system chain that Polkadot now presents as Polkadot Hub. In November 2025, balances, staking and governance moved there from the relay chain, and existing accounts and stakes were carried over automatically, with no action needed from holders.

What is Kusama, and how is it related to Polkadot?

Kusama is Polkadot's sister network, launched in 2019 with its own coin, KSM. It runs nearly the same software and is meant to receive new features first, and its governance and staking cycles are faster: an era there lasts 6 hours instead of 24. Developers use it to test ideas with real value at stake before they reach Polkadot.

Do I need DOT to use apps on Polkadot?

Not always for fees: Polkadot Hub accepts transaction fees in some assets other than DOT, so a wallet that supports this can pay in a stablecoin you already hold there. Staking, voting and buying coretime, however, all require DOT. Keeping a small DOT balance also covers the 0.01 DOT minimum an account needs to stay open.