Worked out · Valheim 1.0.17

Best swords and greatswords

All Valheim swords and greatswords ranked by damage at max level, damage per stamina over a full combo and the secondary attack, and the best one you can make in each biome.

Strongest sword
Frostfire GreatswordGreatsword
334damage
Most damage per stamina
Frostfire Sword3-hit combo
23.8per stamina
Hardest secondary attack
Frostfire Greatsword× 3 for 40 stamina
1,002damage
First you can make
Bronze Sword53 damage at max level
Black Forest

Best sword in each biome

Of the swords you can make by then, the one that kills the biome's hostile creatures in the fewest hits, their weaknesses and resistances applied (every weapon by biome).

Biome	Best sword	Hits	Creatures
Black Forest	Bronze SwordSlash	40	5
Swamp	Iron SwordSlash	43	9
Mountains	Silver SwordSlash + Spirit	33	4
Plains	Silver SwordSlash + Spirit	64	5
Mistlands	KromSlash	48	6
Ashlands	Scourging SlayerSlash + Lightning	60	9
Deep North	Thunderblood GreatswordSlash + Lightning	68	9

All 21 ranked

Sword	From	Damage	Per stamina	Secondary	Stamina	Block
Frostfire Greatsword216 Slash21 Fire97 Frost	Deep North	334	22.3	1,002×3	20	76
Thunderblood Greatsword250 Slash60 Lightning	Deep North	310	20.7	930×3	20	76
Frostfire Sword168 Slash21 Fire97 Frost	Deep North	286	23.8	858×3	16	66
Thunderblood Sword210 Slash60 Lightning	Deep North	270	22.5	810×3	16	66
Nord Greatsword240 Slash	Deep North	240	16	720×3	20	76
Nord Sword200 Slash	Deep North	200	16.7	600×3	16	66
Scourging Slayer188 Slash10 Lightning	Ashlands	198	13.2	594×3	20	64
Primal Slayer188 Slash10 Poison	Ashlands	198	13.2	594×3	20	64
Slayer188 Slash	Ashlands	188	12.5	564×3	20	64
Brutal Slayer188 Slash	Ashlands	188	12.5	564×3	20	64
Dyrnwyn163 Slash10 Fire	Ashlands	173	14.4	519×3	16	57
Krom168 Slash	Mistlands	168	11.2	504×3	20	52
Nidhögg the Thundering153 Slash10 Lightning	Ashlands	163	13.6	489×3	16	57
Nidhögg the Primal153 Slash10 Poison	Ashlands	163	13.6	489×3	16	57
Nidhögg153 Slash	Ashlands	153	12.8	459×3	16	57
Nidhögg the Bleeding153 Slash	Ashlands	153	12.8	459×3	16	57
Mistwalker75 Slash58 Frost15 Spirit	Mistlands	148	12.3	444×3	16	48
Silver Sword93 Slash45 Spirit	Mountains	138	15.3	414×3	12	30
Black Metal Sword113 Slash	Plains	113	10.8	339×3	14	39
Iron Sword73 Slash	Swamp	73	9.7	219×3	10	21
Bronze Sword53 Slash	Black Forest	53	8.8	159×3	8	12

Formula

Damage at max level = base + per level × (max level − 1), each damage type apart; chop and pickaxe left out of the rating (almost every creature ignores them).

Full combo = (combo hits − 1) × hit + hit × the last swing's multiplier; per stamina = combo damage ÷ (stamina × combo hits). Secondary attack = hit × its multiplier.

Stamina and eitr per attack are at skill 0; skill 100 takes a third off (× 0.67) for every weapon alike, so the order doesn't change.

ItemData.GetDamage, Attack.DoMeleeAttack / FireProjectileBurst, Attack.GetAttackStamina, HitData.ApplyResistance in the code of Valheim 1.0.17.

Assumptions

Skill 50 in the weapon's skill, weapons at their max normal level, no stars on the creatures (a star doubles health, two stars triple it).
Every hit lands and only the primary attack is used; no backstab, no stagger bonus, no armor set or mead bonuses.
Area hits (staffs, sledges, atgeirs) are counted against one creature at a time.
Bows and crossbows fire the best arrow or bolt for the target you can make by then, at full draw.