All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Chatting between men and women on the internet is a means to much mischief and corruption. Therefore, such chats are not permissible. However, if the woman intends to propose herself for marriage in some trustworthy sites, and if those who are running them are trustworthy, honest and sincere, and shes proposes herself with a good moral standard and shyness, and if the chat is according to the need, then there is no harm, because it is permissible in the Sharee’ah for a woman to propose herself for marriage to the men who seek to get married.
If a man feels that he wants to get engaged with a woman, it is permissible for him to look at her in the presence of one of her Mahram (non-marriageable relative) or with whom the forbidden seclusion is negated. Then if he has a desire to marry her, he can ask her hand from her Wali (guardian).
We draw your attention, though, dear sister, that you should consider a person who is nearly of the same age like yourself, because great differences in age, may lead to disagreements and divorce in many cases.
But it is permissible for a young person to marry an older person as the Prophet married Khadeejah who was older than him, and married ‘Aa’ishah who was younger than him.
For more benefit, please refer to Fatwa 390778.
Allah knows best.