Start with what the index actually counts
Arton Capital describes its Passport Index Mobility Score as a total built from visa-free, visa-on-arrival, eTA and qualifying fast eVisa access. Henley counts destinations accessible without a prior visa and bases its index on IATA data plus in-house research.
Those definitions overlap, but they are not a promise that every index treats every electronic permission, territory or edge case in the same way.
The destination universe matters
A ranking based on a different number of destinations can produce a different score even when the underlying travel relationships are broadly similar. Tie-breaking and treatment of territories can also affect the visible rank number.
That is why EntryAtlas keeps a source-labelled ranking snapshot separate from its own bundled Passport Power discovery dataset.
Use rank as a comparison lens, not a travel rule
A global position is useful for comparing broad mobility. It does not answer whether one traveller can enter one destination today, for one purpose, on one passport.
For a real journey, move from the ranking to the passport profile, destination guide and official source.