CoinJoin Compared: WabiSabi vs Whirlpool vs JoinMarket

CoinJoin Implementations Overview

CoinJoin is a privacy technique where multiple Bitcoin users combine their transactions into a single joint transaction, making it difficult for chain analysts to determine which inputs funded which outputs. The concept was first proposed by Gregory Maxwell in 2013 and has since been implemented in three major forms: WabiSabi (Wasabi Wallet), Whirlpool (Samourai Wallet), and JoinMarket. Each takes a fundamentally different approach to coordination, fee structure, and anonymity set construction.

The landscape shifted dramatically in April 2024 when DOJ enforcement actions against Samourai Wallet's founders triggered a chain reaction across the Bitcoin privacy ecosystem. Understanding the current state of each implementation requires examining both their technical merits and their operational status.

For broader context on how CoinJoin fits into the Bitcoin privacy landscape alongside techniques like silent payments, PayJoin, and onion routing, see our research on Bitcoin privacy techniques.

WabiSabi: Wasabi Wallet

WabiSabi replaced Wasabi Wallet's original ZeroLink protocol in 2022, introducing keyed-verification anonymous credentials, homomorphic value commitments, and zero-knowledge proofs to enable variable-amount CoinJoins. Unlike Whirlpool's fixed denominations, WabiSabi allows participants to register inputs and outputs of arbitrary amounts while proving to the coordinator that the values balance without revealing which inputs correspond to which outputs.

The protocol executes in five phases: input registration, connection confirmation, output registration, signing, and broadcasting. Each input registers under a unique Tor identity ("Alice"), and outputs register under separate identities ("Bob"). This prevents the coordinator from linking a participant's inputs to their outputs.

A critical event occurred on April 30, 2024, when zkSNACKs (Wasabi's parent company) announced it would shut down its CoinJoin coordination service effective June 1, 2024, citing regulatory uncertainty following the Samourai arrests. However, Wasabi's architecture was designed for coordinator diversity. Version 2.6.0 ("Prometheus"), released in May 2025, eliminated dependency on centralized infrastructure entirely. Users can now connect to third-party coordinators such as OpenCoordinator and SwissCoordinator.

Since version 2.2.0.0, the Wasabi client only participates in rounds where it pays zero coordinator fees (mining fees only). Third-party coordinators may charge their own fees. Rounds typically include 50 to 150 participants with a minimum input count of 21, though a 2024 analysis found that effective per-denomination k-anonymity sets within individual rounds range from 5 to 14.

Whirlpool: Samourai Wallet and Ashigaru

Whirlpool used a Chaumian blind signature scheme with fixed-denomination pools. The original Samourai implementation offered four pool sizes: 0.001 BTC, 0.01 BTC, 0.05 BTC, and 0.5 BTC. Each round mixed exactly five participants, producing five equal-sized outputs. Crucially, remixing was unlimited and free: once a user paid the initial pool fee, their UTXOs could cycle through additional rounds at no extra cost, compounding the anonymity set with each remix.

On April 24, 2024, the DOJ arrested Samourai founders Keonne Rodriguez and William Lonergan Hill. They were charged with conspiracy to commit money laundering and conspiracy to operate an unlicensed money services business. The government alleged Samourai facilitated over $2 billion in transactions, including more than $237 million in criminal proceeds. Both founders pleaded guilty in July 2025 to the money transmitting charge. Rodriguez received a five-year sentence; Hill received four years. Both were fined $250,000 and forfeited $6.3 million.

A significant privacy flaw emerged post-arrest: users who did not run their own Dojo server had their extended public keys (xpubs) sent to Samourai's servers. Law enforcement analysis of seized servers revealed that Samourai retained enough information to trace mobile users' Whirlpool transactions. Users without Dojo should assume their previous mixes are compromised.

Ashigaru, an anonymous fork released in June 2025, has revived Whirlpool as a Tor-only wallet with no clearnet presence. It offers two pool sizes (0.025 BTC and 0.25 BTC) with the same 5% pool fee and free remixing. Sparrow Wallet, which previously integrated Whirlpool, removed the feature after the arrests.

JoinMarket: Decentralized Maker-Taker Model

JoinMarket takes a fundamentally different approach: no central coordinator. Instead, it uses a maker-taker market where makers offer their bitcoin as CoinJoin liquidity and earn fees, while takers initiate CoinJoin transactions and pay makers for participating. An orderbook lists all active maker offers, and takers select counterparties based on fee rates and fidelity bond scores.

Fidelity bonds, introduced in version 0.9.0, allow makers to time-lock bitcoin as a costly-to-fake identity credential. Larger amounts locked for longer periods receive higher trust scores, increasing resistance to Sybil attacks where an adversary floods the orderbook with malicious maker offers.

The original joinmarket-clientserver repository was archived on April 27, 2026, after its final release (v0.9.12, April 2025). Development has migrated to joinmarket-ng, a modern reimplementation maintaining full wire protocol compatibility while adding features like simultaneous maker and taker roles, BIP157 compact block filter support, and an async Python stack. JAM, the JoinMarket web interface, reached version 0.4.1 in August 2025.

JoinMarket's fees are market-driven: makers set their own rates, typically around 0.001% for high-liquidity offers. A default CoinJoin involves 5 to 7 participants. However, a 2025 analysis by Peter Todd argued that JoinMarket's maker-taker model has a fundamental privacy weakness for takers: fee payments and net contribution calculations can reveal which inputs and outputs belong to takers versus makers. This issue was known within the community but its practical significance remains debated.

JoinMarket requires running a full Bitcoin Core node, making it the most technically demanding option. For a comparison of node implementations, see our Bitcoin node software comparison.

Anonymity Set Comparison

Anonymity set size is the core metric for CoinJoin effectiveness: it represents how many possible owners a given output could belong to after mixing. Larger sets make chain analysis harder, but raw participant counts can be misleading.

WabiSabi's variable-amount design reduces toxic change (the unmixed leftover that can link your pre-mix and post-mix UTXOs), but the effective anonymity set within any single round is lower than the raw participant count suggests. Whirlpool's fixed denominations guarantee a clean anonymity set of 5 per round with no change outputs, but require isolating the leftover "doxxic change" in a separate wallet. JoinMarket's per-transaction privacy depends heavily on the number of makers selected and whether the taker's role can be distinguished through fee analysis.

Legal Landscape Post-2024

The April 2024 enforcement actions reshaped the operational environment for Bitcoin privacy tools. Beyond the Samourai arrests, several other developments defined the regulatory landscape:

• zkSNACKs shut down its Wasabi coordinator on June 1, 2024, citing regulatory uncertainty, and barred US citizens from using Wasabi Wallet
• ACINQ removed Phoenix Wallet from US app stores on May 3, 2024, citing concerns about whether self-custodial Lightning wallets could be classified as money services businesses
• OFAC sanctions on Tornado Cash were lifted on March 21, 2025, after the Fifth Circuit ruled that immutable smart contracts are not "property" under IEEPA
• Roman Storm (Tornado Cash developer) was convicted on the unlicensed money transmitting charge in August 2025, with the jury deadlocking on money laundering and sanctions charges; retrial is proposed for October 2026
• The DOJ issued guidance stating it "is not a digital assets regulator," though existing prosecutions have continued

The Samourai case established that operating a CoinJoin coordination service can result in criminal prosecution under money transmitting statutes, regardless of whether the operator ever takes custody of user funds. This has driven a shift toward decentralized coordination (Wasabi third-party coordinators, JoinMarket's peer-to-peer model) and anonymous operation (Ashigaru's Tor-only approach). Users should consult legal counsel regarding the use of privacy tools in their jurisdiction.

How to Choose a CoinJoin Implementation

If usability matters most: Wasabi Wallet offers the most polished experience. CoinJoins run automatically in the background with bundled Tor and no full node requirement. The third-party coordinator ecosystem continues to grow after zkSNACKs' shutdown. This is the most accessible option for users who want privacy without deep technical involvement.

If you prioritize clean anonymity sets with no toxic change: Whirlpool (via Ashigaru) provides fixed-denomination mixing with free unlimited remixes. The tradeoff is operational risk: Ashigaru is maintained by anonymous developers, and the Whirlpool protocol's history includes a demonstrated xpub privacy failure for mobile users.

If decentralization is non-negotiable: JoinMarket (via joinmarket-ng) is the only implementation with no central coordinator at all. The maker-taker market functions peer-to-peer. The cost is technical complexity: a full Bitcoin node is mandatory, and achieving strong privacy requires understanding UTXO management and running multiple sequential CoinJoins.

For users interested in Bitcoin privacy beyond CoinJoin, newer approaches like silent payments and PayJoin offer complementary on-chain privacy without requiring a mixing service. The Lightning Network provides a different privacy model entirely through off-chain transactions and onion-routed payments.

Frequently Asked Questions

Is CoinJoin legal?

CoinJoin itself is a transaction format, not inherently illegal. However, the Samourai Wallet prosecution demonstrated that operating a CoinJoin coordination service can be prosecuted under US money transmitting statutes. The legal risk varies by jurisdiction and by whether you are a user, operator, or developer. The DOJ has stated it is "not a digital assets regulator," but existing enforcement actions continue. Users should consult legal counsel before using privacy tools, particularly in the United States.

What happened to Samourai Wallet and Whirlpool?

On April 24, 2024, the DOJ arrested Samourai Wallet founders Keonne Rodriguez and William Lonergan Hill, charging them with conspiracy to commit money laundering and operating an unlicensed money transmitting business. Both pleaded guilty in July 2025 and received sentences of five and four years respectively. The original Whirlpool service was shut down. Ashigaru, an anonymous fork, revived Whirlpool in June 2025 as a Tor-only wallet.

Which CoinJoin implementation has the largest anonymity set?

Wasabi Wallet (WabiSabi) has the highest raw participant count per round, averaging around 60 participants with a minimum of 21 inputs. However, effective per-denomination k-anonymity within a single round ranges from 5 to 14. Whirlpool guarantees a clean anonymity set of 5 per round with no change outputs, compounding through free remixes. JoinMarket typically involves 5 to 7 participants per transaction. In practice, the effective privacy of any implementation depends on remix frequency, coin control discipline, and post-mix spending behavior.

Does CoinJoin require a full Bitcoin node?

Only JoinMarket requires running a full Bitcoin node (Bitcoin Core). Wasabi Wallet uses compact block filters (BIP158) to verify transactions without a full node, though connecting one improves privacy. Whirlpool (Ashigaru) does not require a full node but strongly recommends running Dojo for xpub privacy. See our node software comparison for setup options.

How much does CoinJoin cost?

Costs vary significantly. Wasabi Wallet (since v2.2) enforces zero coordinator fees, so users pay only mining fees. Whirlpool charges a one-time fee of 5% of the pool denomination (for example, 0.00125 BTC for the 0.025 BTC pool), with all remixes free. JoinMarket's fees are market-driven, typically around 0.001% paid to makers, plus mining fees for the larger collaborative transaction. Mining fees are proportionally higher for all CoinJoin implementations because multi-party transactions are larger in virtual bytes.

Can CoinJoin transactions be traced?

CoinJoin makes tracing significantly harder but not impossible. Chain analysis firms use heuristics such as amount correlation, timing analysis, and post-mix clustering to reduce anonymity sets. The Samourai case revealed that users without their own Dojo server had xpubs exposed to Samourai's servers, enabling demixing. Peter Todd's 2025 analysis argued that JoinMarket takers can often be identified through fee analysis. Effective CoinJoin privacy requires proper coin control, avoiding address reuse, and understanding how post-mix spending can undo the privacy gains.

What are alternatives to CoinJoin for Bitcoin privacy?

Several complementary and alternative approaches exist. PayJoin disguises a payment as a regular two-party transaction, breaking the common-input ownership heuristic without a mixing service. Silent payments allow recipients to publish a static address that generates unique on-chain addresses for each sender, preventing address reuse. The Lightning Network moves transactions off-chain entirely, using onion routing to obscure payment paths. For a comprehensive comparison, see our guide on Bitcoin privacy tools.

This tool is for informational purposes only and does not constitute financial or legal advice. CoinJoin implementations carry varying levels of legal and technical risk depending on your jurisdiction. Data is based on publicly available information as of May 2026. Always verify current software versions, coordinator availability, and legal status before use.