> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stable.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Ethereum comparison

> Stable is fully EVM-compatible. What stays the same, what changes, and what to watch out for when porting from Ethereum.

Stable is fully EVM-compatible, so most Ethereum tools, libraries, and contract patterns work without modification. The sections below walk through what stays the same and what changes when you move from Ethereum to Stable.

## What stays the same

Stable maintains full compatibility with the Ethereum development ecosystem:

| **Area**          | **Compatibility**                                                                                                                                                                                  |
| :---------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Languages         | Solidity, Vyper                                                                                                                                                                                    |
| Tooling           | Hardhat, Foundry                                                                                                                                                                                   |
| Libraries         | ethers.js, web3.js                                                                                                                                                                                 |
| Contract patterns | All standard EVM conventions (ERC-20, ERC-721, ERC-1155, proxies, etc.)                                                                                                                            |
| RPC interface     | Most `eth_*` methods supported (`eth_call`, `eth_sendRawTransaction`, `eth_getBalance`, `eth_getLogs`, `eth_estimateGas`, etc.). For the full list, see [JSON-RPC API](/en/reference/json-rpc-api) |

Existing smart contracts, deployment scripts, and frontend integrations target Stable by changing the RPC endpoint and chain ID.

## What is different

Four behaviors differ from Ethereum.

### 1. Single-slot finality

Ethereum requires multiple block confirmations before a transaction is considered final. Stable provides single-slot finality: a transaction is final once included in a block.

For developers, this means:

* Once a transaction appears in a confirmed block, its state changes are final and irreversible.
* Applications can safely rely on block inclusion as confirmation of settlement.

Even with deterministic finality, applications handling financially sensitive flows should:

* Verify transaction success via RPC or emitted events before proceeding with dependent actions (e.g., unlocks, redemptions).
* Implement retry and reconciliation logic for automation and batch operations to handle transient submission or RPC errors.

### 2. Gas token: USDT0

On Stable, transaction fees are paid in USDT0, not a volatile native token. This provides USDT-denominated, predictable low gas costs.

* Users need USDT0 in their wallet to submit transactions.
* The `value` field in transactions still works for sending USDT0, similar to how ETH is sent on Ethereum.
* See [USDT as gas](/en/explanation/usdt-as-gas-token) for details.

### 3. No priority tips

Stable uses a single-component gas model. There is no tip-based transaction ordering.

* `maxPriorityFeePerGas` is ignored (always 0).
* Transaction ordering is not influenced by fee bidding.
* Wallets should hide or disable the priority tip input field.
* See [Gas pricing](/en/explanation/gas-pricing) for details.

### 4. USDT0 dual-role behavior

USDT0 functions as both the native gas token and an ERC-20 token. This introduces behavioral differences around balance semantics, allowance safety, and certain opcode assumptions. For the full details, see [USDT0 behavior on Stable](/en/explanation/usdt0-behavior).

## Quick comparison

| **Parameter**                         | **Stable**         | **Ethereum**              |
| :------------------------------------ | :----------------- | :------------------------ |
| Gas token                             | USDT0              | ETH                       |
| Finality                              | Single-slot        | Multi-block confirmations |
| Block time                            | \~0.7 seconds      | \~12 seconds              |
| Priority tip (`maxPriorityFeePerGas`) | Ignored (always 0) | Used for ordering         |
| EIP-1559 transaction format           | Supported          | Supported                 |
| EVM compatibility                     | Full               | N/A                       |

## Next recommended

<CardGroup cols={2}>
  <Card title="USDT as gas" icon="fuel" href="/en/explanation/usdt-as-gas-token">
    Understand the asset model that replaces ETH for gas.
  </Card>

  <Card title="Gas pricing" icon="calculator" href="/en/explanation/gas-pricing">
    Review the single-component fee model in detail.
  </Card>

  <Card title="USDT0 behavior on Stable" icon="alert-circle" href="/en/explanation/usdt0-behavior">
    Audit contracts for dual-role asset semantics, allowance safety, and `EXTCODEHASH` behavior.
  </Card>
</CardGroup>