This page explains how to say "I love you with all my heart" in Spanish, in case you have said the simple te quiero or te amo too many times and want to be a bit more original.
How to say "I love you with all my heart" in Spanish
I love you with all my heart in Spanish is:
Te quiero con todo mi corazón.
Te amo con todo mi corazón.
Which one is better to use depends on where you are (country and region) and what the relationship is (lovers vs. friends or family – see details below).
What the individual words mean
Te means you (as object). Unlike English, you put it immediately before the verb in Spanish and no other words should be between the two.
Quiero (infinitive querer) means I love or I like. It does not always mean romantic love and you can use it not only when talking to your wife, husband, or lover, but also when talking to good friends or family.
Amo (infinitive amar) means I love in romantic sense. You normally don't use Te amo with your friends or family. There are big regional differences in the Spanish speaking world and the use or quiero vs. amo varies, but the safe way for someone who can't speak Spanish very well and is not aware of the specifics of the particular culture is to use quiero.
Con means with.
Todo means all or whole.
Mi means my.
Corazón means heart. This is a good word to remember if you will be talking about love regularly. You can also call your boyfriend or girlfriend mi corazón (my heart) or you can say Mi corazón está roto (My heart is broken) when it's over.
Here you can learn the other ways how to say I love you very much / so much / a lot in Spanish.
Here you can learn how to reply when some tells you one of them: I love you too in Spanish.