MetaAOEAoE IV and AoE II counters
Your opponent makes a unit, you read its line: the safest answer is in green, the others follow. The same counters MetaAOE shows in game, against your opponent's civ.
Age of Empires IV
AoE IV counters: standard units
The units every civ (or nearly) can make.
Archers
Horsemen
Men-at-arms
Mangonels
LongbowmenHorsemenMen-at-armsMangonels
SpearmenArchersMen-at-arms
Handcannoneers- HorsemenSpearmen
Knights - KnightsSpearmen
Crossbowmen
Camel riders 
LancersSpearmenCrossbowmenCamel riders- Men-at-armsCrossbowmenHandcannoneersKnights
- CrossbowmenHorsemenArchersMangonels
- HandcannoneersHorsemenKnightsMangonels
Gunpowder infantry (Streltsy, Janissaries)HorsemenKnightsMangonels
Zhuge NuHorsemenKnightsMangonels
GrenadiersHorsemenKnights
Horse archersArchersCrossbowmenHorsemen
MangudaiArchersCrossbowmenHorsemen- Camel ridersSpearmenArchersMen-at-arms
Camel archersArchersMen-at-armsCrossbowmen
War elephantsSpearmenCrossbowmenHandcannoneers
Tower elephantsCrossbowmenSpearmenHandcannoneers- MangonelsHorsemenKnights
SpringaldsHorsemenKnights
CulverinsHorsemenKnights
BombardsHorsemenKnightsCulverins
TrebuchetsHorsemenKnights
RamsMen-at-armsSpearmenKnights
Siege towersMen-at-armsSpearmenKnights
MonksHorsemenKnights
TradersHorsemenKnights
AoE IV counters: civ unique units
A unit only one civ has: what beats it.
KeshiksSpearmenCrossbowmenCamel riders
CataphractsCrossbowmenHandcannoneersSpearmen
Varangian guardsCrossbowmenHandcannoneersKnights
LimitaneiArchersMen-at-armsHandcannoneers
LandsknechteArchersHorsemenKnights
Royal knightsSpearmenCrossbowmenCamel riders
ArbalétriersHorsemenKnightsMangonels
JanissariesHorsemenKnightsMangonels
SipahiSpearmenCrossbowmenCamel riders
Great bombardsHorsemenKnights
GhulamsCrossbowmenArchersKnights
Desert raidersSpearmenArchersCamel riders
Camel lancersSpearmenCrossbowmenMen-at-arms
SamuraiCrossbowmenHandcannoneersKnights
Mounted samuraiSpearmenCrossbowmenCamel riders
Onna-mushaArchersCrossbowmenHorsemen
Yumi ashigaruHorsemenMen-at-armsMangonels
OzutsuHorsemenKnightsMangonels
DonsoArchersMen-at-armsHandcannoneers
Musofadi warriorsArchersHorsemenMen-at-arms
SofaSpearmenCrossbowmenCamel riders
Javelin throwersHorsemenMen-at-armsMangonels
Fire lancersSpearmenArchersMen-at-arms
Palace guardsCrossbowmenHandcannoneersKnights
Nest of beesHorsemenKnights
Ghazi raidersSpearmenArchersCamel riders
Black ridersSpearmenCamel ridersKnights
Hospitaller knightsSpearmenCrossbowmenCamel riders
SerjeantsCrossbowmenHandcannoneersKnights
Genoese crossbowmenHorsemenMen-at-armsMangonels
Iron pagodasSpearmenCrossbowmenCamel riders
YeomenHorsemenMen-at-armsMangonels
HobelarsSpearmenKnights
DemilancersSpearmenCrossbowmenCamel riders
RiddariSpearmenCrossbowmenCamel riders
Huihui paoHorsemenKnights
These counters in game, against their civ
In game, MetaAOE reads your opponent's civ and keeps its counters one key away: Alt+C, the best answer shows in green, over the game. Free, on Overwolf.
Age of Empires II
AoE II counters: standard units
The units every civ (or nearly) can make.
Archers
Skirmishers
Mangonels
Knights
Scouts
Spearmen / Pikemen
Long swordsmen- KnightsSpearmen / Pikemen
Camels
Monks 
Men-at-armsArchers
Hand cannoneers- SkirmishersKnightsMen-at-arms
Light cavalry 
Cavalry archersSkirmishersLight cavalryCamels
Battle elephantsMonksSpearmen / Pikemen- MonksLight cavalry
Eagle warriorsScouts - Eagle warriorsLong swordsmenKnightsHand cannoneers
- MangonelsKnightsLight cavalry
RamsMen-at-armsLong swordsmenKnights- Hand cannoneersSkirmishersKnightsMangonels
- Light cavalrySpearmen / PikemenCamelsKnights
- CamelsSpearmen / PikemenLong swordsmenArchers
- Spearmen / PikemenArchersLong swordsmenHand cannoneers
- Long swordsmenArchersHand cannoneersCavalry archers
ScorpionsKnightsLight cavalryMangonels
Bombard cannonsLight cavalryKnights
TrebuchetsLight cavalryKnights
AoE II counters: civ unique units
A unit only one civ has: what beats it.
ConquistadorsCamelsSpearmen / PikemenSkirmishers
War wagonsSpearmen / PikemenCamelsLong swordsmen
Woad raidersArchersHand cannoneersKnights
CataphractsCamelsMonksKnights
Teutonic knightsArchersCavalry archersHand cannoneers
HuskarlsKnightsLong swordsmenHand cannoneers
SamuraiArchersKnightsHand cannoneers
Jaguar warriorsArchersKnightsHand cannoneers
Plumed archersSkirmishersKnightsMangonels
LongbowmenSkirmishersMangonelsKnights
Chu Ko NuMangonelsSkirmishersKnights
Genoese crossbowmenSkirmishersMangonelsKnights
Elephant archersSkirmishersSpearmen / PikemenMonks
MamelukesArchersLong swordsmenHand cannoneers
JanissariesSkirmishersKnightsMangonels
KeshiksSpearmen / PikemenCamelsLong swordsmen
LeitisSpearmen / PikemenCamelsMonks
BoyarsCamelsSpearmen / PikemenMonks
TarkansSpearmen / PikemenCamelsLong swordsmen
Magyar huszarsSpearmen / PikemenCamelsMonks
KamayuksArchersHand cannoneersLong swordsmen
Organ gunsKnightsLight cavalryMangonels
SlingersKnightsLight cavalryArchers
Throwing axemenArchersKnightsHand cannoneers
Rattan archersLong swordsmenMangonelsHand cannoneers
GhulamsKnightsCamelsHand cannoneers
BerserksArchersKnightsHand cannoneers
Counters civ by civ (AoE IV)
The units each civ plays most in its popular builds, and how to beat them.
Abbasid Dynasty
Ayyubids
Byzantines
Chinese
Delhi Sultanate
English
French
Golden Horde
House of Lancaster
Holy Roman Empire
Japanese
Jeanne d’Arc
Jin Dynasty
Knights Templar
Macedonian Dynasty
Malians
Mongols
Order of the Dragon
Ottomans
Rus
Sengoku Daimyo
Tughlaq Dynasty
Zhu Xi’s Legacy