stringent vs rigorous

stringent and rigorous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
stringent	No	Yes	No	No
rigorous	No	Yes	No	No

As adjectives, stringent and rigorous are synonyms defined as:

stringent and rigorous: demanding strict attention to rules and procedures

Other synonyms of stringent include tight.

stringent (adjective)	rigorous (adjective)
demanding strict attention to rules and procedures	demanding strict attention to rules and procedures
	rigidly accurate; allowing no deviation from a standard