How to Track a Flight in Real Time
FR24 · FlightAware · ADS-B Exchange · RadarBox · Sources: FAA · ICAO · tool vendors
Modern commercial aircraft broadcast their position about once per second over ADS-B on 1090 MHz. A global network of ground-based receivers (often hobbyist-operated) and satellite receivers (Aireon) picks up those signals and feeds them to public trackers. The big four for consumer use are Flightradar24 (FR24), FlightAware, ADS-B Exchange, and RadarBox. They differ in coverage, filtering (which aircraft are hidden), schedule integration, and pricing. ADS-B is excellent for "where is the plane right now" but cannot show pilot intent, runway assignment, or many ground operations. This guide explains the tools and what they can and can't tell you.
How flight tracking works
Every commercial aircraft equipped per the global ADS-B Out mandates transmits a 1090 MHz broadcast containing the aircraft's GNSS-derived position, altitude, velocity, callsign, and ICAO 24-bit address. Anyone with a $20 USB dongle and a small antenna can receive these signals; thousands of hobbyists do, and they feed data to the public trackers in real time.
The mandates in force as of 2026:
- →FAA — ADS-B Out required for most controlled airspace since 1 January 2020
- →EASA — Phased 2017–2020 for IFR aircraft over 5,700 kg MTOW
- →Australia (CASA) — Since 2017 above FL290
- →Other jurisdictions — various national rules aligned with ICAO Annex 10 Vol IV
For deeper background, see our ADS-B explained guide.
The four major trackers
The market leader. Roughly 35,000+ ground receivers globally — the largest feeder network in the industry, with the strongest coverage in Europe. Polished consumer interface; deep integration with airline schedules. Filters certain government and sensitive aircraft at jurisdictional request.
Strongest in North America; integrates directly with FAA data feeds in addition to ADS-B. Around 30,000 ground receivers. Excellent for accurate ETAs on US domestic routes, gate assignments, and inflight progress. Filters at FAA / customer request.
The "unfiltered" tracker. Approximately 5,000–7,000 active feeders — smaller network, but the principle is that every aircraft broadcasting ADS-B is shown. This includes military, government, and sensitive flights that FR24 and FlightAware filter. Popular with researchers, journalists, and OSINT users.
Competes with FR24 on consumer features; similar interface and aircraft database. Smaller feeder network. Targets aviation enthusiasts and offers airline / dispatch tier products.
Quick comparison
| Feature | FR24 | FlightAware | ADS-B Ex. | RadarBox |
|---|---|---|---|---|
| Ground receivers | ~35k+ | ~30k | ~5–7k | smaller |
| Filtering of sensitive flights | Yes | Yes | No | Yes |
| Best regional coverage | Europe | North America | Global enthusiast | Mixed |
| Schedule / ETA integration | Deep | Deepest (FAA feed) | Minimal | Moderate |
| Historical playback | Paid | Paid | Paid | Paid |
| Free tier exists | Yes | Yes | Limited | Yes |
How to look up a specific flight
- Use the flight number (e.g.,
BA178,UA902) on FR24 or FlightAware — both index by carrier+number. - Or the aircraft registration (e.g.,
N12345,G-XWBA) — useful when the flight number changes between legs. - Or the ICAO 24-bit hex address (e.g.,
A12345) — the most stable identifier; doesn't change. - For a specific route or airport, search the airport ICAO/IATA code (e.g.,
EGLL/LHR) and view arrivals / departures.
On mobile, official apps from FR24 and FlightAware support push alerts: "tell me when my flight lands" or "alert when departure is announced."
What ADS-B can show
- ✓Current latitude / longitude / altitude (1–2 second update on a good ground link, slower on satellite)
- ✓Ground speed, heading, vertical rate
- ✓Callsign and aircraft type / operator (derived from registration databases)
- ✓Squawk code (emergency, hijack, comms fail special codes flag visually)
- ✓Track history during the flight (depending on tier)
- ✓NIC / NACp integrity flags — these surface when an aircraft's GNSS is degraded, which is how ADS-B telemetry is used to detect GPS interference patterns at scale
What ADS-B can't show
- ✗Pilot intent — what runway the flight is targeting, which approach, where it will hold
- ✗ATC clearance text — what controllers told the crew
- ✗Why a flight is doing what it's doing — diversion reason, hold reason, level change reason
- ✗Cabin / cargo state — passenger count, freight, fuel onboard
- ✗Aircraft below 1,200 ft AGL in many areas — ground stations don't always pick up low-altitude traffic; receivers are line-of-sight
- ✗Non-equipped aircraft — some light GA, gliders, hot-air balloons, certain military
- ✗Sensitive flights filtered by commercial trackers (varies by tracker)
Privacy and filtered aircraft
ADS-B is unencrypted and unauthenticated by design — the original goal was open surveillance. That creates a privacy tension for owners who don't want their movements public. Several mitigations exist:
- →FAA Privacy ICAO Address (PIA) — eligible US-registered aircraft can swap to a temporary ICAO 24-bit address that doesn't match the public registry
- →LADD (Limiting Aircraft Data Displayed) — FAA program asking commercial data providers to filter specific tail numbers
- →Operator filters — FR24 / FlightAware honor government and customer requests to filter
- →ADS-B Exchange deliberately does not honor these filters — its position is that public-broadcast data is public
For airline travelers, none of this matters in practice — scheduled commercial flights are always visible. The filters affect business jets, government aircraft, and some military.
Beyond the consumer trackers
- →OpenSky Network — research-oriented, open API, bulk historical data for non-commercial use. Used by academics studying air-traffic patterns.
- →Aireon — space-based ADS-B reception via Iridium NEXT. Provides oceanic coverage. Used by ANSPs (NAV Canada, NATS) for surveillance over oceans.
- →Self-hosted receivers — a Raspberry Pi with a $20 SDR dongle plus dump1090 software lets you see live traffic in your area and contribute back to community networks.
Practical tips for passengers
- →Set a flight alert the day before — get push notifications on departure delay and landing
- →Track the inbound aircraft — your flight's delay is usually a downstream effect of the prior leg
- →If your flight diverts, you'll see it on the map within seconds — and you can identify the alternate before any in-cabin announcement
- →If you don't see your flight at all, check whether the carrier files under a different operating code (codeshares are common) and try the operating-airline number
Sources
- FAA — ADS-B Out final rule (14 CFR 91.225, 91.227); LADD and PIA program documentation
- EASA — ADS-B Out implementation rules
- ICAO Annex 10 Vol IV — Surveillance Radar and Collision Avoidance Systems
- RTCA DO-260B — ADS-B 1090ES technical standard
- Flightradar24, FlightAware, ADS-B Exchange, RadarBox — vendor documentation
- OpenSky Network — research data documentation
- Aireon — space-based ADS-B operational data