What AIS is, and what it is not
Worth thirty seconds before any of the vendor claims make sense, because several of the differences between these platforms are consequences of how the underlying system works rather than of engineering effort.
AIS, the Automatic Identification System, is a VHF transponder standard. Ships above a certain size are required to carry it under SOLAS rules, and it broadcasts identity, position, course, speed and some voyage detail on a short cycle. It was built for collision avoidance between vessels in sight of one another, not for a global surveillance network, and much of the shape of this market follows from that original purpose.
Because it is VHF, a shore receiver hears roughly forty nautical miles. Terrestrial networks therefore give excellent coverage near populated coasts and nothing at all in mid-ocean, which is why MarineTraffic’s community-hosted antenna network is dense around Europe and thin in the South Atlantic. Satellite reception fills the gap and brings its own problem: a satellite passing overhead hears every transponder in an enormous footprint at once, and in busy waters those messages collide and are lost.
Two things follow. First, coverage is really revisit rate, and it varies by sea area in ways a global figure hides completely. Second, AIS is self-reported. A transponder broadcasts what it is told to broadcast, and it can be switched off, or configured to report an identity that is not the vessel’s own. Everything a platform tells you about dark activity, identity laundering or spoofing is inference layered on an absence, and that inference is the product you are buying.
Three names, one company
Anyone shortlisting ship tracking software runs into the same three names within an afternoon: Kpler, MarineTraffic and FleetMon. It is worth knowing before the first call that they are the same company.
Kpler announced the acquisition of both on 15 February 2023, and it did not stop there: Spire Maritime followed in 2025. The MarineTraffic deal closed on 7 March 2023 and FleetMon on 13 March 2023. FleetMon had already been acquired by MarineTraffic before that, so the transaction folded a chain of two into one group. Both targets were founded in 2007, MarineTraffic in Athens and FleetMon in Rostock, and between them they held a large share of the public-facing ship tracking market.
Kpler's stated reasoning, from chief executive François Cazor at the time, was that "we believe the time has come to marry commodity and maritime intelligence into one single platform". That is an accurate description of the strategy and it explains the product boundaries you will meet today: Kpler's centre of gravity is what the ship is carrying and what that means for a commodity market, and the ship tracking is the substrate underneath it.
For a buyer the practical consequence is narrow but real. A shortlist of Kpler, MarineTraffic and FleetMon is not three vendors competing for your business. It is one vendor with three front doors, and the negotiating leverage you think you have across them does not exist.
What each one is actually for
All of these platforms ingest AIS, the transponder system ships use to broadcast identity, position, course and speed. Reception is either terrestrial, from coastal antennas, or satellite, which is how coverage extends past the roughly forty nautical miles a shore station reaches. Every platform here blends both. The differentiation is almost never the positions themselves; it is the layer built on top.
Kpler sells trade and commodity intelligence. The question it answers is not "where is this ship" but "how much crude is on the water heading to northwest Europe this month, and how has that changed". Its customers are energy traders, commodity analysts and sanctions compliance teams, and the cargo-level inference is the product.
MarineTraffic sells the map, and it is the name the general public knows. It grew a terrestrial network by recruiting the community to host receivers, which is why its shore coverage is dense in populated coastal regions and why it became the default answer to "what is that ship outside my window".
Lloyd's List Intelligence sells risk and identity. Its Seasearcher platform is built around ownership, counterparty risk, sanctions screening, trade-based money laundering detection and ultimate beneficial owner discovery, with AIS SeaOrbis offering the positional data through an API. The buyer is trade finance, insurance, legal and government rather than a trader watching a spread.
FleetMon was the enterprise-leaning AIS feed of the three, supplying data to industrial customers further down the supply chain. Since the merge, former FleetMon AIS partners have been migrated onto MarineTraffic processes.
Put plainly: if you need to know what is on the ship, look at Kpler. If you need to know who is behind it and whether dealing with them is legal, look at Lloyd's List. If you need to see where it is, MarineTraffic has always been enough.
The two ends of the same group, on coverage, pricing model and who each is sold to.
Why the coverage numbers do not compare
Every vendor publishes a headline. Read them side by side and the temptation is to rank them. Resist it, because they are not measuring the same thing.
Kpler states it operates "the world's largest combined terrestrial and satellite AIS network", with 661,000+ vessels tracked, 1.2 billion+ AIS messages processed per day, and 9,000+ total stations combining terrestrial receivers, satellite coverage and roaming AIS, of which it says 920+ new terrestrial stations were installed during 2025.
Lloyd's List Intelligence states 550,000+ vessels tracked, 750 million+ daily AIS positions, 3,000+ trusted data sources, 100% coverage of the active commercial fleet, and 80+ analysts verifying and enriching the data.
The gap between 661,000 and 550,000 vessels is not a coverage deficit. The larger figure counts everything with a transponder, which includes pleasure craft, tugs, fishing vessels and port service boats. Lloyd's List's claim is bounded differently and more usefully for its buyer: complete coverage of the active commercial fleet, which is the population that matters if you are underwriting or sanctioning.
Likewise 1.2 billion messages a day against 750 million positions a day. A message is not a position. One vessel sitting at anchor broadcasting every few seconds generates enormous message volume and almost no information.
The figure worth asking for in a sales conversation is neither of these. Ask about revisit rate in the specific sea areas you care about, and ask what happens in the places where reception is hardest: high latitudes, mid-ocean, and anywhere a vessel has switched its transponder off. The last one is where these platforms genuinely differ, because inferring a dark vessel's track is analysis rather than reception, and the analysis is the thing you are paying for.
Pricing, and the disappearing entry point
This market has moved decisively towards enterprise contracts in the last three years, and that is the change most likely to affect a small team.
Kpler is enterprise only. There is no free tier and no self-serve API signup; third-party comparisons put entry around $2,500 a month, which should be read as an indication rather than a quote, because the real number comes from a sales conversation shaped by your data volumes and licensing terms.
MarineTraffic historically sold credits, which made it the obvious place for a developer to prototype. It has moved away from that towards enterprise subscriptions, with pricing behind a sales contact. A free tier still exists for the consumer-facing map, and the REST API retains per-call pricing that keeps moderate usage viable without a contract, but the trajectory is clear.
Lloyd's List Intelligence publishes no pricing, which is unsurprising for a platform sold to trade finance and insurance.
The result is that a two-person team wanting AIS positions for a product has fewer honest options than in 2022. The remaining paths are the smaller API-first providers, or per-call MarineTraffic usage before you outgrow it. Neither is a criticism of the majors; the analytics layer is expensive to build and they are pricing for the customers who need it. It does mean that "which platform is best" is the wrong first question. The first question is whether you need an analytics platform or an AIS feed, because they are different purchases and only one of them is sold to small teams.
How to choose without wasting a quarter on evaluations
Four questions settle most of it.
Do you need cargo, or only position? Cargo-level inference is the single most expensive thing in this market and the main reason to be talking to Kpler at all. If you need to know where a fleet is and when it will arrive, you are buying something much cheaper than you have been quoted.
Is the output a decision about a counterparty? If somebody will be approved, insured, financed or refused on the basis of what the platform says, you want the vendor whose product is identity and risk rather than the one whose product is flows. Sanctions exposure and beneficial ownership are research disciplines with analysts behind them, not fields on an AIS message.
Who consumes it? A trading desk wants a terminal. A compliance team wants an auditable record with sources attached. A product engineer wants an API and will find a beautiful interface irrelevant. These three buyers are well served by different vendors, and the mismatch is the usual reason an expensive contract goes unused.
What happens when the transponder goes dark? Ask every vendor this and compare the answers carefully. It separates the platforms that report AIS from the platforms that reason about it, and it is the question whose answer you will care about most in the one situation that actually matters.
What to put in the evaluation
If you are running a formal comparison, these are the clauses and tests that separate the vendors once the demos are over.
Licensing of derived data. The most consequential term in an AIS contract and the one most often missed. Can you store positions, for how long, and can you show a derived figure to your own customers? A platform that permits internal analysis but forbids redistribution is unusable underneath a product, and you will discover that at renewal rather than at signature.
Historical depth and replay. Ask how far back the archive goes and whether you can replay a period rather than only query it. Compliance and dispute work is retrospective by nature, and an archive that begins when your contract did is worth much less than it sounds.
The API, tested with your own volumes. Rate limits, whether history costs the same as live, and whether bulk extraction is permitted at all. Per-call pricing that looks cheap in a demo behaves very differently against a backfill.
A blind test on vessels you already know. Take twenty vessels whose movements you can verify independently, include several that have called at a sanctioned port or gone dark, and run them through each platform without telling the vendor which ones they are. This is the only part of an evaluation that reliably distinguishes these platforms, and it takes an afternoon.
Who answers when the data is wrong. Ownership records and risk flags carry consequences and they are sometimes wrong. Ask what the correction process is and how quickly it runs. The vendors with analysts have an answer; the vendors reselling a feed do not.
What is left outside the group
Consolidation has not left the market empty, but it has gone further than the 2023 deals. VesselFinder remains a general-purpose tracking platform in the MarineTraffic mould. Spire Maritime, which owned its own satellite constellation and was the obvious independent source of satellite AIS, is no longer independent either: Kpler completed the acquisition of Spire Global's maritime business on 25 April 2025 for $241 million. That business was itself exactEarth, which Spire had acquired in 2021. So a fourth name that a buyer would reasonably shortlist as an alternative now sits inside the same group, and the satellite constellation Kpler describes as proprietary is the one that came with it.
A tier of smaller API-first providers has grown into the space the majors vacated when they moved upmarket, and for a team that needs positions rather than intelligence they are usually the right answer.
The structural point for a buyer is that the independent options are concentrated at the two ends: raw feeds below, and Lloyd's List Intelligence at the top with a genuinely different product. The middle, where a mid-sized company wants good tracking with some analysis and a price it can approve without a procurement cycle, is the part consolidation thinned out.
Questions people ask
- Is MarineTraffic owned by Kpler?
- Yes. Kpler announced the acquisition of MarineTraffic and FleetMon on 15 February 2023. The MarineTraffic deal closed on 7 March 2023 and FleetMon on 13 March 2023. All three operate under Kpler.
- What is the difference between Kpler and MarineTraffic?
- They sit at different layers of the same group. MarineTraffic answers where a vessel is, with the widest public recognition and a community-grown terrestrial network. Kpler answers what the vessel is carrying and what that means for a commodity market, and is sold to traders, analysts and sanctions teams on enterprise terms.
- Which AIS platform has the best coverage?
- The published figures are not comparable. Kpler states 661,000+ vessels and 1.2 billion+ messages a day; Lloyd’s List Intelligence states 550,000+ vessels, 750 million+ daily positions and 100% of the active commercial fleet. The larger vessel count includes non-commercial craft, and messages are not positions. Ask instead about revisit rate in your sea areas.
- Is there a free AIS vessel tracking option?
- MarineTraffic keeps a free consumer-facing map, and its REST API retains per-call pricing usable without an enterprise contract. Kpler has no free tier and no self-serve API. For programmatic access at low volume, the smaller API-first providers are now the realistic entry point.
- What does Lloyd’s List Intelligence do that the others do not?
- It is built around identity and risk rather than movement: counterparty risk, sanctions screening, trade-based money laundering detection and ultimate beneficial owner discovery, through Seasearcher, with AIS SeaOrbis providing positional data by API. It states 80+ analysts verify and enrich the data, which is the part that cannot be derived from a transponder feed.
- Can these platforms track a vessel that has switched off its AIS?
- Not directly, because there is nothing to receive. What the stronger platforms do is infer: flagging the gap, modelling a likely track and correlating with other signals. That inference is analysis rather than reception, it varies enormously between vendors, and it is the right question to test any of them on.
Sources
Every price, limit and date above was checked against these pages on the day shown. Where a figure has since moved, the vendor’s own page is the authority and this one is a snapshot.
- 1Kpler completes acquisition of Spire Maritime, strengthening maritime intelligence capabilities · KplerConfirms completion on 25 April 2025. The $241 million value, the exactEarth lineage and the UK Competition and Markets Authority review are from Spire Global’s own SEC filing and contemporaneous trade coverage.Checked
- 2Kpler Acquires MarineTraffic and FleetMon for maritime sector expansion · KplerThe vendor announcement, dated 15 February 2023, and the source of the François Cazor quotation about marrying commodity and maritime intelligence.Checked
- 3Ship Tracking, Real-Time Vessel Tracking · KplerSource of the published coverage claims: 661k+ vessels, 1.2bn+ AIS messages per day, 9,000+ total stations and 920+ new terrestrial stations installed in 2025.Checked
- 4Lloyd’s List Intelligence · Lloyd’s List IntelligenceSource of 550k+ vessels tracked, 750m+ daily AIS positions, 3000+ data sources, 100% coverage of the active commercial fleet and 80+ analysts, and of the Seasearcher and AIS SeaOrbis product descriptions.Checked
- 5FleetMon and MarineTraffic Merge: process for former FleetMon AIS partners · MarineTrafficConfirms the operational merge of FleetMon into MarineTraffic and the migration of former FleetMon AIS partners.Checked
- 6Kpler Acquires MarineTraffic and FleetMon · gCaptainTrade press coverage used to corroborate the closing dates of 7 March and 13 March 2023 and the founding years and locations of both companies.Checked