Airtight
A single downloadable HTML file that tracks a cryptocurrency portfolio's profit and loss entirely inside your browser, with no account, server, or cloud sync involved.
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Description
Most portfolio trackers ask you to connect exchange accounts or paste in API keys so a company's servers can watch your holdings for you — which means a third party now has a live view of your crypto wealth. Airtight takes the opposite approach: it's a single HTML file, like a self-contained mini-app, that you download once and open in your browser. There's no company account, no server processing your trades, and no internet connection required after you've downloaded it — closer to keeping your finances in a personal spreadsheet than logging into a cloud dashboard, except with real portfolio math built in.
Under the hood, Airtight runs entirely client-side: transactions are entered manually, or imported from CSV/Excel exports (paid version) from over 70 exchanges and wallets, and profit/loss is computed using FIFO (first-in-first-out) cost-basis accounting, with live prices pulled from an optional CoinGecko API call — the only network request the tool makes, and it's configurable. Data can be encrypted with a password using AES-GCM before being stored locally. The free version caps manual entries at 50 transactions and has no CSV import; the $30 one-time premium version removes the transaction cap and adds bulk CSV/Excel import. It's sold, not open source, and distributed through the sell.app marketplace rather than a traditional SaaS website.
💬 Our review
The short version: if you want to track crypto profit and loss without handing your exchange data to another cloud service, Airtight's single-file, browser-only approach genuinely delivers on that privacy promise, but it's a young, one-person product with real limits.
Against established portfolio trackers like CoinTracker or Kubera (both cloud-based, subscription-priced, built to sync automatically via exchange APIs) and the open-source Wealthfolio (also privacy-first and local-first, but free and fully auditable since its code is public), Airtight's pitch is narrower: no account, no server, works offline, for a one-time $30 rather than a recurring subscription. That's good value if the feature set matches your needs, but the free tier's 50-transaction cap will push active traders into the paid unlock quickly, CSV import — the main convenience feature — is paywalled, and because the product isn't open source, 'nothing leaves your browser' has to be taken on trust rather than verified by reading the code, unlike Wealthfolio. For someone with a modest, mostly-manual portfolio who values privacy over automation, it's a fair one-time purchase; for active multi-exchange traders, the lack of live API sync and the import paywall are real friction.
💰 Pricing
📊 Global score
🤖 AI-enriched data
Free: manual entry capped at 50 transactions, live pricing, FIFO P&L, charts, AES-GCM encryption. Premium: $30 one-time (a $20 launch price was observed at research time), unlocks unlimited transactions and CSV/Excel import from 70+ exchanges. Paid via crypto (BTC, ETH, SOL, USDT, USDC).
Pros
Runs fully offline as a single HTML file, no account or server
One-time $30 purchase instead of a recurring subscription
AES-GCM password encryption for locally stored data
FIFO cost-basis P&L calculations and live pricing built in
Cons
Not open source, so the 'nothing leaves your browser' privacy claim can't be independently verified
Free tier capped at 50 manually-entered transactions, no CSV import
Sold through a third-party marketplace (sell.app) rather than the developer's own site
No live exchange API sync — CSV import (paid) or manual entry only