A local worksheet for a bitcoin CSV. Not a launch, and not a claim about search rank.
Not tax advice · reviewed 25 October 2026
A bitcoin-only worksheet on your machine
BasisFix reads River Account Activity, River Bitcoin Activity, an older River shape, Coinbase, Kraken, Cash App, a Strike monthly statement, three Swan CSV shapes, a Gemini ledger saved as CSV, and a generic map. It matches lots for one tax year. The work happens in the browser. The download is a review with a tax pro. There is no account. A few typed rows, with no file, can be compared on the cost-basis calculator.
What is actually different
- The file stays put. Koinly, CoinTracker, CoinLedger, ZenLedger, TokenTax, and Bitcoin.Tax all take an import into an account on their side. BasisFix does not.
- The scope is narrow. There is no DeFi decoder, no NFT schedule, and no exchange API. Swan, Strike, and Gemini files are read only when the header matches the shapes on their guides, and several columns are assumptions. River’s own Cost Basis column is still not read. Those are limits, and the guides say so.
- Launching at $29. One tax year, one-time, not a subscription. The preview is free. A license key unlocks the export. This build has no payment provider. The dev key unlocks a file on your machine and processes nothing.
What is not different
A free look at the gain, with the download locked until a license key, is how Koinly, CoinLedger, and CoinTracker already sell the report. CoinTracker’s paid plans auto-renew. Koinly’s published price is per tax year, starting at $49 for 100 transactions, and it is not described as a renewal. BasisFix is launching at $29 for one tax year, under that $49 entry tier, and it still has no API sync and no 1099-DA reconciliation. Past a hundred transactions the other products are selling a different amount of software.
Clams is the other Bitcoin-only tool that keeps books on the machine. Their Standard page advertises a free tier with email sign-in. Their enterprise page also says running it yourself is $199 per person per year. Both lines were public on 25 October 2026. Clams covers on-chain, Lightning, and multisig accounting. It is not this one-year browser worksheet.
Search rank was not measured. The longer comparison is in the repo’s competitor notes, not on this page.
A reasonable job for the worksheet
- Export the CSV yourself from River, Coinbase, Kraken, Cash App, Strike, Swan, or Gemini.
- Open the reconciler, pick the year, and pick FIFO, HIFO, or specific identification.
- Read the warnings. Interest is on the income summary, not on Form 8949. A missing cost stays out of the total.
- If you need a worked example with no upload of your own, the demo report is the fictional 2024 classic sample.
Questions
Does the CSV leave the browser?
no. Parsing and lot matching run locally. The page does not upload the file, and it does not sign in to an exchange.
Is a free preview unusual?
No. Koinly, CoinLedger, and CoinTracker already show a preview and charge for the download. The difference here is that the preview is computed on your machine, and that this build has no checkout.
Is $29 a discount on Koinly?
Koinly, CoinLedger, ZenLedger, and TokenTax each list a $49 entry tier for about 100 transactions. BasisFix is launching at $29 per tax year, one-time, not a subscription. The preview is free and a license key unlocks the export. There is no checkout in this build. The $29 price still has no API sync and no 1099-DA reconciliation.