Study of 1st house:

The 1st house is indicative of the personality of a person and the 7th house is indicative of one's life partner. If the lord of 1st and the 7th house are sitting in each other's houses, it is a good significator of love marriage.

Specific yogas are present

If study of 1st and 7th houses indicates navpanchamyog and saptamyog, then it is beneficial towards love marriage as well.

Specific planets are strong in horoscope

The 5th house also indicates love. If Shukra (Venus) and Buddh( Mercury) are in the 5th house, if the lord of the 5th house is also in 7th house and vice versa, it again indicates fortunes and gains through love.

The above factors are used to makelove marriage prediction, in vedic astrology.

Presence of auspicious planets

If auspicious planets such as Chandra (Moon) and Budh (Mercury) are in the 7th house, they bring about an early marriage, in the age range of 18 to 20. When Guru (Jupiter) transits from the 1st, 3rd or 11th house and aspects the 7th house, it helps for the settlement of marriage. Chandra (Moon), Guru (Jupiter) and Shukra (Venus) in strong positions are generally good for marriage to occur at the correct time.

Presence of inauspicious planets

Makar and kumbhrasi can cause delay. The lord of these rashis are Shani (Saturn), who is known to delay things. Rahu and Ketu are also malefic planets that cause delay.Mangal (Mars) in the 7th house also creates a lag for marriage. Shani delays marriage to post the age of 30, and presence of Rahu can take the marriage age Prediction to over 30 also.

Kundali of partners are checked

The rashis of both partners in online janam kundali are checked for compatibility in thinking. Rashi's are grouped according to their tattwa or elements. For example, Agni (fire) and Jal (water)rashi are incompatible whereas Agni (fire) and Vayu (wind) are compatible. So, Leo being a agni sign would be incompatible with scorpio which is a water sign but more of a personality match with gemini which is a wind sign.

Gun milan

Gun Milan is done to check compatibility on all aspects and points are given accordingly, using Ashtakoot gun milan system. A score of 18 and above is considered good for marriage.

Houses, planets and yogasare checked

The relation of the 1st and 7th house are checked. Yogas being formed are looked into. The formation of MrityuShadashtak yoga indicates a lot of marriage issues, problems&enemity.It is a clear indicator of incompatibility whereas Navpanchami yoga indicates very good compatibility.. Position of mangal or Mars is checked in the horoscope to see if either of the partners are manglik. Mars placed in the 1st , 4th, 7th, 8th, and 12th house indicates manglik dosh. Such a person can marry only another manglik. They are of high stress temperament, and would not be compatible with other personality types. Strength of auspicious planets like Guru (Jupiter) and Shukra (Venus) are checked in both horoscopes.

Vedic astrology deals with the issue of compatibility in this way by taking a deep dive into the kundali – checking horoscope, rashi, nakshatra, charan and panchang.