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How Bridging Works on Horizen

The Native Bridge​

Horizen supports two bridges: the native OP Stack bridge and the Stargate bridge. This page covers how the native bridge works — it is the canonical, most trust-minimized way to move ETH between Base and Horizen. For bridging ZEN, USDC, cbBTC, or other chains, see Bridge Assets via Stargate.

NetworkBridge URL
Mainnethttps://hub.horizen.io/
Testnethttps://hub-testnet.horizen.io/

The native bridge relies entirely on the OP Stack's optimistic rollup security model — the same model that secures Base itself. No third-party protocol is involved in the bridging path.

Deposit and Withdrawal Mechanics​

Moving assets in each direction behaves very differently. Understanding this before you bridge will prevent surprises.

Deposits: Base → Horizen​

Deposits are straightforward and fast. When you deposit from Base to Horizen:

  1. Your ETH (or supported asset) is locked in the bridge contract on Base
  2. An equivalent amount is minted on Horizen
  3. Funds arrive on Horizen within a few minutes

There is no challenge window for deposits. Once the transaction is confirmed on Base and the Horizen Sequencer processes it, your funds are available.

Bridge UI — set direction from Base to Horizen

Set direction: Base → Horizen

Bridge UI — enter deposit amount

Enter amount and confirm

Deposit success screen

Deposit confirmed

Withdrawals: Horizen → Base​

Withdrawals are a two-step process and take significantly longer due to the 7-day challenge window that is a core property of the optimistic rollup model.

Withdrawal flow diagram — two-step process with 7-day challenge window
7-Day Withdrawal Window

Withdrawals from Horizen to Base take a minimum of 7 days to complete. It is the security mechanism of the optimistic rollup model. Plan accordingly. Do not initiate a withdrawal if you need your funds on Base sooner than 7 days from now.

Two Transactions Required

A withdrawal requires two separate transactions:

  • Transaction 1: Initiate the withdrawal on Horizen (costs gas on Horizen)
  • Transaction 2: Claim the funds on Base after 7 days (costs gas on Base)

You must return to https://hub.horizen.io/ after the 7-day window to complete the claim. Funds are not automatically sent to your Base wallet.

Bridge UI — set direction from Horizen to Base

Step 1 — Initiate: set direction Horizen → Base, enter amount

Claim is ready screen after 7-day window

Step 2 — Claim: return after 7 days and submit the claim on Base

What the Bridge Supports​

The native bridge currently supports ETH between Base and Horizen.

note

Additional assets may be available through the bridge UI. Always verify the asset list directly at https://hub.horizen.io/ — this documentation reflects the state at the time of writing and the bridge may be updated independently.

Trust Model​

The native bridge inherits the full security of the OP Stack and Base:

  • Deposits are secured by Base's smart contracts and finality guarantees
  • Withdrawals are secured by the 7-day optimistic challenge window — any invalid state can be disputed during this period before funds are released
  • No third party is involved in the bridging path — there is no relayer, liquidity provider, or off-chain validator between you and the contracts

This makes the native bridge the most trust-minimized option available. The tradeoff is the 7-day withdrawal window.

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