If hearts are the symbol for love, what would you say best fits as the symbol of hate?

The swastika is a fairly obvious symbol of hate, same with a white pointed hood.

They aren't normally used in a generic fashion though.

Maybe a red lightsaber?

The Nazis appropriated it from other cultures. Being a fairly simple symbol, it shows up in religions around the world. "Nazis" are not the first thing most Indians think of when they see a swastika.

I agree that in western culture it's pretty synonymous with a host of vile connotations, and it's been successfully appropriated - like red baseball caps. But it's not fair to the swastika, and it certainly isn't a universal meaning for the symbol, whereas the heart has no other meaning for most people in the world; that is, of there's any symbolism assigned to a heart by a person, it's probably "love."

I can't suggest a similar, universal symbol for hatred, although as someone else suggested, a clenched fist is probably a good candidate. 👊🏽
- a clenched fist is probably a good candidate. 👊🏽
  
  Looks like a fist-bump lol

✝️ definitely this

symbol of a torture device. checks out.

The liver. It produces bile.

A boot stamping on a human face — forever.

It's obviously a fucking swastika. It's not even a question. The swastika has been used as a symbol of hate since the late 1930's.

Not universally, though. There are parts of the world where the swastika has had positive nazi-free associations for centuries. I occasionally drive home past this temple which is decorated with swastikas. One of the oldest churches in the city has swastikas in its stained glass windows. And one of the staff members where I work is named Swastika because it's an old family name in her country of origin and her parents only heard about WWII as something that happened far away.
- I think OP was playing the role of "a westerner with absolutely no knowledge of history or religion" when they made the comment.

Tesla symbol

Also, red MAGA hats. Often seen together these days.

or piss. We love to piss on things we hate. Been doing it for centuries.

I think the whole heart thing comes from where you feel it and hate absolutely occupies the heart too. Same way we associate sadness with heartbreak.

Robert Sternberg saw three main elements in hatred:

a negation of intimacy, by creating distance when closeness had become threatening;

an infusion of passion, such as fear or anger;

a decision to devalue a previously valued object.

The front-facing fist 👊: Threatening, intense, replicable (most people have hands)

The down-facing knife 🔪: sharp, cold, calculated

There are also very specific symbols of hatred, like the swastika and the Nazi salute, white-hooded robes and burning crosses, the flag of the Daesh, the Z of the RAF for the West et al., but all of those are tied to certain ideologies and cultures and might not make any sense outside of relevant situations.

🖕🏻or ❌?

😡 probably?

🔫

🧨⚡💣💥☠️💩
- 🤡🖕🖕🖕🖕🖕
  
  🙄

Back in the day in the kids' comics I remember at least one occasion where the spade card suit was used for that purpose. (Britain, 1980s/1990s)

A character's speech bubble contained "I h♠te homework" or something similar. Might have been spinach instead of homework. Or school. Anything an irreverent protagonist might not like.

The artist was clearly using this as a counterpart to the more often seen "lo♥e", but as an adult thinking about it now, I have to wonder if the artist had forgotten about the potential racial connotation of using it, or if they hadn't but didn't think it was particularly important.

Either way, ♠ could be used as a symbol of hate if the context permits it. Maybe best avoided if you're looking for a generic one though.

In MSPA it refers to an emotion where you hate someone so much it makes you horny for them... for what it's worth.
I ♥️ my dog.

I ♠️ my dog.
- I ♣️ my dog.