Most Koinly reviews are written by affiliates trying to sell you a subscription. This one is written by a CPA firm that cleans up Koinly reports for a living, so we see exactly where it shines and where it quietly produces wrong numbers. Here is the honest version.
Short take: Koinly is one of the best crypto tax tools for active, multi-chain traders, and it is genuinely accurate when its data is complete. The catch is that “when its data is complete” does a lot of work in that sentence.
Disclaimer: This is an independent review for informational purposes. We are not affiliated with Koinly. Always consult a qualified CPA regarding your specific situation.
Quick Verdict
Koinly earns its reputation for active crypto investors who trade across several exchanges and chains. The capital gains engine is solid, the coverage is broad, and the cost basis options are flexible. Where it struggles is the same place every crypto tax tool struggles: DeFi classification and any coin it cannot trace back to a purchase. If your activity is simple, Koinly is more than enough. If it is complex, Koinly gets you most of the way and a human finishes the job.
What Koinly Does Well
Broad Exchange and Chain Coverage
Koinly connects to a very wide range of exchanges, wallets, and blockchains. For someone with activity spread across many platforms, this breadth is the main reason to choose it.
Flexible Cost Basis Methods
Koinly supports multiple cost basis methods, which matters for matching your accountant’s approach and for legally optimizing gains. Not every tool offers this flexibility at lower tiers.
Clean Capital Gains Math
Once the data is complete and correctly labeled, the actual gain and loss calculations are reliable. The engine is not the problem. The inputs are.
Where Koinly Struggles
This is the part affiliate reviews skip.
DeFi Classification
Koinly imports DeFi activity but routinely mislabels it. Liquidity pool entries get tagged as trades, staking rewards as deposits, and wrapped-token swaps as disposals. Each wrong label changes your tax, and only a human catches them.
Missing Source Data Produces Phantom Gains
When Koinly cannot trace a coin to a purchase, it assumes a $0 cost basis and treats the entire sale as profit. A single unconnected wallet can inflate your gains by thousands of dollars.
The Per-Wallet Transition
The 2025 per-wallet rule changed how basis is tracked, and accounts built under the old universal method can show surprising figures this year.
Who Koinly Is Right For
- Simple portfolio (a few buys and sells on one or two exchanges): Koinly alone is plenty.
- Active, multi-chain trader: Koinly is a strong fit, with a review pass before filing.
- Heavy DeFi or very high volume: Koinly as the data layer, a crypto CPA for reconciliation and sign-off.
A client trading across five exchanges and three chains came to us sure his Koinly report was wrong: it showed roughly $80,000 in gains. The engine was fine. The problem was a closed exchange he never connected and several mislabeled DeFi transactions. After we connected the missing source, matched transfers, and corrected the labels, his real gain was about $24,000. Koinly was accurate the whole time. It just needed the right inputs.
The Bottom Line
Koinly is an excellent crypto tax tool and a deserving market leader for active traders. It is accurate, broad, and flexible. But it is software, and software cannot interview you about that weird 2021 transaction or decide how to treat an ambiguous DeFi event. For simple situations, run it yourself with a careful review. For complex ones, use Koinly as the foundation and bring in a crypto CPA to reconcile and defend the final numbers.
If your Koinly report looks off, or you just want a professional to confirm it before you file, that is exactly what we do.
Key Takeaways
- Koinly is accurate when its data is complete and correctly labeled
- Strengths: broad coverage, flexible cost basis methods, reliable gains math
- Weaknesses: DeFi labeling, wrapped/bridged tokens, $0 basis from missing sources
- Confirm per-wallet settings for 2025 and later
- Simple portfolios: Koinly alone. Complex ones: Koinly plus a CPA