Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
It is permitted to use a razor to shave armpit hair.
With regard to your question, The Standing Committee for Islamic Research and Ifta’ states:
Muslims enjoy the highest standard of personal hygiene of all the people in the world.
In Islam, cleanliness and purification are not only requirements for the performance of worship, or when embracing Islam, but are essential parts of a Muslim’s faith.
Allah says in the Qur’an: “Truly, Allah loves those who turn unto Him in repentance and loves those who purify themselves (by taking a bath and cleaning and washing thoroughly their private parts, bodies, for their prayers etc.)” (Al Baqarah 2:222)
It is permitted to use a razor to shave armpit hair, because the object is to remove the hair, whether by plucking, shaving or some other method.
Plucking is better if one can manage it, because the Prophet (peace and blessings upon him) said: “The fitrah (natural disposition) consists of five things: circumcision, trimming the mustache, cutting the nails, plucking the armpit hair and shaving the pubic hairs.” (Al-Bukhari and Muslim)
Almighty Allah knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.
Source: www.islamqa.info