Local only — no network access

1099-DA difference ledger

Load two exports, map the columns, and get a line-by-line attribution of the difference. Nothing is uploaded: this page is built so that every outbound request is blocked by the browser itself.

Step 1 · Data

Load the two documents

CSV exports. Nothing is sent anywhere — the files are read by this page and never leave it.

Software export Koinly / CoinTracker / CoinLedger gains or transactions CSV
1099-DA / broker statement Form 1099-DA export, or one row per disposal
Sample = 8 software rows vs 7 broker rows with eight planted difference types.
Verification

How to prove this page never called home

1. The header blocks itCSP default-src 'none' means the browser refuses every outbound request — scripts, fonts, beacons, fetch. Not a promise: an enforced policy.
2. Watch it yourselfDevTools → Network → clear → load two files → run. The count stays at zero.
3. DisconnectSave this page, turn off Wi-Fi, open it from disk. Same ledger, same numbers.

This build is the pilot version: the full ledger is available without a license key. The licensed self-serve build adds saved profiles and a signed audit trail, not access to your data — because there is no access to have.