testnet.md

title	Testnet
title-aliases	Testnet3 Testnet4
topic-categories	Developer Tools
primary_sources	title BIP94
optech_mentions	title url High block production rate on testnet leading to degradation of service /en/newsletters/2018/07/03/#testnet-high-block-production-rate title url Discussion of resetting testent /en/newsletters/2018/09/04/#discussion-of-resetting-testnet title url CVE-2018-17144 duplicate inputs bug exploited on testnet /en/newsletters/2018/10/02/#cve-2018-17144-duplicate-inputs-bug-exploited-on-testnet title url Open source release of esplora, a block explorer supporting testnet /en/newsletters/2018/12/11/#modern-block-explorer-open-sourced title url Feedback requested on signet, an alternative to testnet /en/newsletters/2019/03/12/#feedback-requested-on-signet title url C-Lightning #3268 changes the default network from Bitcoin testnet to Bitcoin mainnet /en/newsletters/2019/12/04/#c-lightning-3268 title url BOLTs #682 updates `init` message to prevent mainnet nodes from connecting to testnet nodes /en/newsletters/2020/02/26/#bolts-682 title url Question: will there by a testnet4? /en/newsletters/2020/08/26/#will-there-be-a-testnet4-or-do-we-not-need-a-testnet-reset-once-we-have-signet title url C-Lightning #3763 adds a new RPC used to open a channel to every public testnet LN node /en/newsletters/2020/09/16/#c-lightning-3763 title url Bitcoin PR review club on signet with questions and answers about testnet /en/newsletters/2020/10/14/#bitcoin-core-pr-review-club title url Instructions for creating taproot transactions on testnet /en/newsletters/2021/10/20/#testing-taproot title url Software incorrectly implementing compact block filtering failed on testnet /en/newsletters/2021/11/10/#additional-compact-block-filter-verification title url Bitcoin Core #23882 updates documentation about testnet3 to mention the BIP30 problem /en/newsletters/2022/01/12/#bitcoin-core-23882 title url Bitcoin Core #18554 prevents the same wallet from being used on mainnet and testnet /en/newsletters/2022/05/04/#bitcoin-core-18554 title url BOLTs #968 adds default TCP ports for nodes using Bitcoin testnet and signet /en/newsletters/2022/06/01/#bolts-968 title url Question about why both testnet and signet use the `tb1` bech32 address prefix? /en/newsletters/2023/01/25/#why-doesn-t-signet-use-a-unique-bech32-prefix title url Service bit for Utreexo set for testing on testnet and signet /en/newsletters/2023/03/15/#service-bit-for-utreexo title url Bitcoin Core #28354 begins rejecting non-standard transactions by default on testnet /en/newsletters/2023/09/06/#bitcoin-core-28354 title url Core Lightning 24.02 includes the fix for a transaction parsing bug on testnet /en/newsletters/2024/02/28/#core-lightning-24-02 title url Discussion about resetting and modifying testnet /en/newsletters/2024/04/10/#discussion-about-resetting-and-modifying-testnet title url CoreDev.tech Berlin event with discussion about testnet4 /en/newsletters/2024/05/01/#coredev-tech-berlin-event title url BIP and experimental implementation of testnet4 /en/newsletters/2024/06/07/#bip-and-experimental-implementation-of-testnet4 title url Bitcoin Core PR Review Club about testnet4 /en/newsletters/2024/07/12/#bitcoin-core-pr-review-club title url Bitcoin Core #29775 adds a `testnet4` configuration option /en/newsletters/2024/08/09/#bitcoin-core-29775 title url BIPs #1601 adds BIP94 specifying testnet4 /en/newsletters/2024/08/09/#bips-1601 title url New time warp attack discovered during analysis of testnet4's attempted time warp fix /en/newsletters/2024/08/16/#new-time-warp-vulnerability-in-testnet4 title url New CPUNet testnet announced with a modified PoW algorithm designed for CPU-only mining /en/newsletters/2024/08/23/#cpunet-testnet-announced title url Rust Bitcoin #2945 introduces support for testnet4 /en/newsletters/2024/10/11/#rust-bitcoin-2945 title url Discussion about retiring testnet3 and hard forking testnet4 to remove difficulty reset rule /en/newsletters/2025/03/28/#discussion-of-testnets-3-and-4 title url LND #9620 adds testnet4 support /en/newsletters/2025/04/04/#lnd-9620 title url Draft BIP to replace testnet4 with testnet5 /en/newsletters/2026/06/12/#draft-bip-for-testnet5 title url BIPs #2196 adds BIP95, a draft specification for testnet5 /en/newsletters/2026/07/03/#bips-2196
see_also	title link Signet topic signet
excerpt	**Testnet** is a testing network included with Bitcoin Core and supported by many other Bitcoin applications. **Testnet3** is the longest-running incarnation of testnet as of 2024, with **testnet4** currently being a recently started replacement.

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