---
title: Stacks Blockchain Networks
description: Stacks Blockchain Networks
sidebar_position: 3
---

### Stacks Blockchain Networks

- [x] **Krypton** is a Stacks 2 testnet with a fixed, two-minute block time, called `regtest`. Regtest is generally unstable for regular use, and is reset often. See the [regtest documentation](understand-stacks/testnet) for more information on using regtest.

- [x] **Testnet** (old Xenon) is the Stacks 2 public testnet, which runs PoX against the Bitcoin testnet. It is the full implementation of the Stacks 2 blockchain, and should be considered a stable testnet for developing Clarity smart contracts. See the [testnet documentation](understand-stacks/testnet) for more information on the public testnet.

- [x] **Mainnet** is the fully functional Stacks 2 blockchain, see the [Stacks overview](understand-stacks/) for information on running a Stacks node, mining, stacking, and writing Clarity smart contracts.
