Herakles vs Heracles

Herakles and Heracles both are nouns.

Word	Noun	Adjective	Verb	Adverb
Herakles	Yes	No	No	No
Heracles	Yes	No	No	No

As nouns, Herakles and Heracles are synonyms defined as:

Herakles and Heracles: (classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality

Other synonyms of Herakles include Alcides, Hercules.

Herakles (noun)	Heracles (noun)
(classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality	(classical mythology) a hero noted for his strength; performed 12 immense labors to gain immortality