dTax vs Koinly: Open Source vs Closed Source Crypto Tax Software
dTax vs Koinly: Open Source vs Closed Source Crypto Tax Software
dTax is an open-source crypto tax engine you can self-host, audit, and verify every calculation, while Koinly is a closed-source SaaS platform with broader exchange integrations and a more beginner-friendly interface. dTax offers a free tier for up to 50 transactions and Pro at $49 per tax year. Koinly starts free but charges $49 to $279 per tax year for tax report downloads.
Feature Comparison
| Feature | dTax | Koinly |
|---|---|---|
| Open Source | Yes (AGPL-3.0 core) | No |
| Self-Hosting | Yes | No |
| Free Tier | 50 transactions | Portfolio tracking only (no reports) |
| CSV Import | 23 exchange formats | 400+ exchange formats |
| API Sync | Coming soon | 170+ exchanges |
| Cost Basis Methods | FIFO, LIFO, HIFO, Specific ID | FIFO, LIFO, HIFO, ACB |
| Form 8949 | Yes (CSV, PDF, TXF) | Yes (CSV, PDF) |
| 1099-DA Reconciliation | Yes | No |
| DeFi Support | AI-powered classification | Manual tagging + some auto-detect |
| Countries | US (more planned) | 20+ countries |
| Wash Sale Detection | Yes (30-day window) | Yes |
| Tax Loss Harvesting Tool | Yes | Yes (paid tiers) |
| Portfolio Tracking | Basic | Advanced with charts |
| AI Features | Claude-powered classification + chat | None |
| CPA/Accountant Tools | Multi-client dashboard | Accountant portal |
Open Source vs. Closed Source: Why It Matters
The most fundamental difference between dTax and Koinly is transparency. dTax's tax engine is open source under the AGPL-3.0 license, which means:
Audit Every Calculation: You can inspect exactly how dTax computes your cost basis, applies lot selection, and generates Form 8949. If you disagree with a calculation, you can trace the logic line by line. With Koinly, the calculation engine is a black box. You see the output but cannot verify the algorithm.
This matters because crypto tax calculations involve nuanced edge cases: how are forks handled? What happens when you transfer between wallets? How are staking rewards valued at the time of receipt? With open source, the answer is always in the code. According to a 2024 survey by the Blockchain Association, 34% of crypto investors expressed concern about trusting proprietary tax software with their financial data.
Community-Verified Accuracy: dTax's open-source engine has been reviewed by developers and tax professionals who contribute test cases and bug reports. The tax engine currently passes 791 unit tests covering edge cases from wash sales to cross-wallet transfers to DeFi protocol interactions.
No Vendor Lock-In: If dTax's SaaS service were to shut down, you would still have the open-source engine and all your data. With Koinly, if the service closes, your transaction history and calculations become inaccessible.
Self-Hosting: dTax can be deployed on your own infrastructure using Docker. Your transaction data never leaves your server. For privacy-conscious users or CPAs handling client data, this is a significant advantage. Koinly has no self-hosting option, as all data is stored on their servers.
Pricing Comparison
dTax Pricing (Per Tax Year)
| Tier | Price | Transactions | Key Features |
|---|---|---|---|
| Free | $0 | Up to 50 | Full tax engine, Form 8949, wash sale detection |
| Pro | $49 | Unlimited | AI classification, all export formats, priority support |
| CPA | $199 | Unlimited (multi-client) | Client management dashboard, bulk processing |
Koinly Pricing (Per Tax Year)
| Tier | Price | Transactions | Key Features |
|---|---|---|---|
| Free | $0 | Unlimited (no reports) | Portfolio tracking only |
| Newbie | $49 | 100 | Tax reports, basic support |
| Hodler | $99 | 1,000 | Tax reports, portfolio insights |
| Trader | $179 | 3,000 | Tax reports, priority support |
| Oracle | $279 | 10,000+ | Custom limits, priority support |
Key Pricing Differences:
dTax Pro at $49 gives you unlimited transactions. To get unlimited transactions on Koinly, you need the Oracle tier at $279, making dTax 82% cheaper for high-volume traders. For casual investors with fewer than 50 transactions, dTax's free tier includes full tax reports, while Koinly's free tier only provides portfolio tracking without downloadable reports.
Koinly charges per tax year, and if you need to recalculate a prior year (common when you discover missing transactions), you must pay again for that year. dTax's open-source engine lets you recalculate any year at no additional cost.
Exchange Support and CSV Parsing
Koinly's biggest advantage is its breadth of integrations. With API connections to over 170 exchanges and CSV support for 400+ formats, Koinly covers virtually every exchange a user might encounter.
dTax currently supports 23 CSV parsers, covering the most popular exchanges including Coinbase, Kraken, Binance, Crypto.com, OKX, Bybit, Bitget, Gate.io, HTX, MEXC, Koinly export format, CoinTracker export format, and Cryptact format. API sync is on the development roadmap.
If you primarily use major exchanges, dTax's parser coverage is likely sufficient. If you trade on obscure regional exchanges, Koinly's broader support is an advantage. That said, dTax can import Koinly's universal export format, so you can use Koinly to aggregate data from unsupported exchanges and then import into dTax for tax calculation.
DeFi and On-Chain Transaction Support
DeFi tax calculation is where both platforms face challenges, and where dTax takes a different approach.
Koinly: Supports wallet connections for major blockchains (Ethereum, BSC, Polygon, Solana, etc.) and attempts to auto-classify DeFi transactions. However, complex DeFi interactions (liquidity pool entries/exits, yield farming, bridging) often require manual review and tagging.
dTax: Uses AI-powered transaction classification with Claude Sonnet for DeFi transactions. The AI analyzes transaction patterns, protocol interactions, and token movements to automatically classify complex DeFi activities. dTax also integrates blockchain indexers for Ethereum (including Polygon, Arbitrum, Optimism, and Base via Etherscan) and Solana via Solscan.
After Congress repealed the DeFi broker reporting rule on April 10, 2025, DeFi transactions do not appear on 1099-DA forms. This makes automated classification tools particularly valuable, since all DeFi tax reporting falls on the taxpayer.
IRS Compliance and Tax Reports
Both dTax and Koinly generate IRS-compliant Form 8949 reports. However, there are differences in compliance features:
dTax advantages:
- 1099-DA reconciliation engine that matches broker-reported data against your calculated figures
- Covered vs. noncovered security classification per IRS Notice 2024-56
- Pre-audit sandbox that lets you review your entire tax position before filing
- TXF export format (V042) for direct TurboTax import, in addition to CSV and PDF
- Form 8949 Box A-F categorization with proper adjustment codes
Koinly advantages:
- Tax reports for 20+ countries (Australia, UK, Canada, Germany, etc.)
- Country-specific forms (e.g., ATO format for Australia, SA108 for UK)
- Automatic currency conversion for international users
For US-based taxpayers, dTax's compliance features are more comprehensive. For international users, Koinly's multi-country support is a clear advantage.
Data Privacy and Security
Data privacy is a growing concern in crypto tax reporting. You are uploading your complete financial history, including every transaction, wallet address, and portfolio balance.
dTax: Offers self-hosting, meaning your data can remain entirely on your own infrastructure. Even when using the hosted SaaS version, dTax's open-source codebase lets you audit exactly what data is collected and how it is processed.
Koinly: All data is stored on Koinly's cloud infrastructure. Koinly's privacy policy states they may share anonymized data with analytics partners. There is no self-hosting option.
According to the 2025 Chainalysis Crypto Crime Report, stolen personal financial data from centralized platforms increased 40% year-over-year. Self-hosting eliminates this attack vector entirely.
When to Choose dTax
dTax is the better choice if you:
- Value transparency and want to verify exactly how your taxes are calculated
- Are a developer or technical user comfortable with open-source tools
- Prioritize privacy and want to self-host your tax data
- Are a CPA or tax professional who needs multi-client management at a fixed price
- Are a high-volume US trader and want unlimited transactions at $49 instead of $279
- Need 1099-DA reconciliation to match broker-reported data against your calculations
- Use DeFi heavily and want AI-powered transaction classification
When to Choose Koinly
Koinly is the better choice if you:
- Are a beginner who wants a polished, user-friendly interface with minimal setup
- Trade on many exchanges and need API sync with 170+ platforms
- File taxes outside the US and need country-specific tax reports
- Want portfolio tracking with advanced charts and analytics alongside tax reporting
- Use many obscure exchanges where CSV parser support matters
- Prefer a fully managed service without any self-hosting or technical setup
Migrating from Koinly to dTax
Switching from Koinly to dTax is straightforward:
- Export your transaction history from Koinly in their universal CSV format
- Import the Koinly CSV into dTax (dTax includes a dedicated Koinly format parser)
- Review the imported transactions for accuracy
- Select your cost basis method and generate your tax report
Your historical cost basis will be preserved through the import, so you do not need to re-enter years of transaction data manually.
FAQ
Can I switch from Koinly to dTax mid-year?
Yes. Export your complete transaction history from Koinly in CSV format and import it into dTax. dTax's Koinly-format parser will correctly interpret the data. However, you should use the same cost basis method (FIFO or Specific ID) that you used on prior-year returns to maintain consistency. Switching methods mid-year can create complications if the IRS reviews your returns.
Does dTax support as many countries as Koinly?
Currently, dTax focuses on US tax compliance (Form 8949, Schedule D, TXF for TurboTax). Koinly supports 20+ countries with country-specific tax reports. If you file taxes outside the US, Koinly is currently the better option. dTax has international tax support on its roadmap.
Is open-source crypto tax software trustworthy?
Open-source software is inherently more trustworthy than closed-source alternatives because anyone can inspect the code. dTax's tax engine passes 791 unit tests, and every calculation can be independently verified. The AGPL-3.0 license ensures the source code remains publicly available. Major financial institutions and governments worldwide rely on open-source software (Linux, PostgreSQL, OpenSSL) for critical operations. Transparency is a feature, not a limitation.