Flight Ledger

Flight Ledger is a private ledger of your flying: every flight, what it cost, what United credited for it, and whether those numbers agree. While flight trackers help with your next departure, the Flight Ledger helps you understand the flying you've already done and how your MileagePlus account is performing. It runs client-side, entirely on your own machine.

Nothing to install, no account to create. The whole app runs inside your browser (SQLite compiled to WebAssembly), and your ledger stays there. No ledger contents are uploaded to a third-party server. You do have an option to turn on Google Drive sync for backups and multi-device access. One click loads a demo ledger if you'd rather look around before importing anything.

Try it now at app.flightledger.net →

Backstory

I built Flight Ledger to make sense of my own flying. I have been based near SFO and IAH, both United hubs, and fly frequently for work. My flight history was scattered across airline accounts, MileagePlus activity, and email receipts.

I wanted one private place to see where I had flown, what it cost, and whether United had credited it correctly, without signing up for another service, logging into multiple accounts, or digging through old receipts.

Quick start

1. Download your "My Activity" CSV from united.com (MileagePlus → My Activity).
2. Drop it on the Flights page. That one file builds your flight history and starts the Premier tracker: PQP and PQF against the thresholds United published for each year, drawn as the same arc gauges united.com uses, plus lifetime miles and Million Miler progress.
3. Add more when you feel like it. You can also import a Flighty or myFlightradar24 CSV to bring years of history on any airline, aircraft types and tail numbers included. The email receipts add the money side. The app tells the formats apart on its own.

Re-importing the same file changes nothing, so pull a fresh CSV whenever you like. And export a backup from Settings once you're set up.

Note that your ledger has no cloud copy by default. To back up your data in the cloud, you can turn on Google Drive sync.

Where Flight Ledger is different

Feed it your email receipts and it becomes an accounting tool. Drop .eml files or a whole Gmail label exported through Takeout. It recognizes 23 receipt formats, covering United, American, Delta, Southwest, Alaska, Lufthansa and others, plus bookings made through Amex, Chase, and Capital One travel portals. Then:

• A reissued ticket is priced as one economic unit across the flights that actually flew, so the value carried between tickets is not counted twice.
• Refunds and reimbursements tracking. Separate business and out-of-pocket costs.
• Cost per mile (CPM) in gross, personal, and per-route flavors.
• Cash flow gets its own view.
• Whatever doesn't line up lands in a reconcile queue: flights United never credited, duplicates, foreign-currency tickets counted at 1:1, clocks that disagree with the distance.

Also in the box

Statistics, mostly: a zoomable route map drawn from bundled data, the total miles you've flown, a sortable table of every route you fly, fleet statistics down to individual airframes enriched from the FAA registry, travel mix, fare-class economics, and a printable annual report. Estimates wear a ≈ symbol, and a value you typed by hand is not overwritten by an import. The reasoning behind each rule lives in the docs.

Your data

Your ledger stays local by default. In the browser build it lives in your browser's own storage (OPFS); "clear site data" deletes it, so export backups. Self-hosted, each account is one SQLite file under data/, and the server binds to 127.0.0.1 only.

One exception is Google Drive sync. If you turn it on, it copies the backup from your browser to a private folder of your own Drive when you press sync. The public site also counts page views and a few feature events by name only (such as demo loads), but never sees ledger contents. Details in the privacy policy.

Self-hosting and development

npm install
npm run dev

Open http://localhost:3000. To explore with sample data first, press "Load demo data" on the empty dashboard and erase it later from Settings → Erase all data. Requires Node 22.13 or newer, the first release where node:sqlite runs without a flag.

npm run build:browser exports the entire app as static files (out/) that run with no server at all; serve them from any static host. For a project path, rebuild with -- --base /path. For the official flightledger.net deployment, copy .env.example to .env; a deployment on any other origin needs its own Google OAuth client ID for Drive sync.

Commands

Stack

Next.js 15 (App Router), TypeScript, Tailwind CSS v4, Recharts, d3-geo, and Node's built-in node:sqlite (no ORM, no native modules). Fonts, airports, and map data are bundled, with no third-party runtime data services.

Documentation

Status

Flight Ledger is in daily use. All the data imports are manual by design: you feed it files, and nothing happens without you. The app does not connect to your Gmail or poll airlines on a schedule.

License

MIT. Redistributed third-party material keeps its own terms: the Barlow and IBM Plex Mono fonts (SIL OFL 1.1) and eighteen test fixtures from two MIT-licensed corpora, inventoried in THIRD_PARTY_NOTICES.md with full license texts under licenses/. The bundled datasets are public domain or public data: OurAirports, Natural Earth, the FAA aircraft registry, and the BIS city-pair table, which credits the FlyerTalk thread it was compiled from in its header.

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Not affiliated with or endorsed by United Airlines. "United", "MileagePlus" and "Premier" are their trademarks, used here only to describe what this tool reads.