Blood is kept at a minimum; there isn't that much. In a few episodes, there are larger amounts, as a character bleeds out and such.
In an early Episode we see Charming defending his newborn baby, and he gets slashed by a sword which leaves a blood trail along his chest. He is also stabbed again, but they focus on his face rather than the wound itself. This wound is not fatal.
Stealthy, the dwarf, dies by an arrow. Several characters die. There are some characters that are impaled where a sword or spear is seen going straight through, including through armor. There are very many episodes where hearts are removed from a persons chest using magic. Sometimes the person remains alive, and is controlled by the one holding their heart, and sometimes their hearts are crushed resulting in their death. Some of these situations are tragic, and could be upsetting to younger viewers. For example, a mother kills her daughter's fiance, a queen kills a poor man during his wedding, a woman kills her father, a woman kills her former lover.
There are many unintentional deaths that can be quite tragic or disturbing. For example: A woman is tricked into killing her own mother by placing her heart back into her body when it has been cursed. A man desires to be free from his corrupt parents, and taking a potion from Rumpelstiltskin without knowing what it will do, he tries to trick his parents into drinking it, but they switch it with a vial given to a very kind young couple, and the potion turns them into puppets, and the man responsible discovers this right before their young son comes home to find them this way. A man is also tricked into dying by trying to resurrect his father and not being aware that he will have to die as a result. There are scenes where the ware-wolf is unaware that he/she is the ware-wolf, and kills people that he/she loves. There is also a scene where someone tries to help someone else by giving them magical powers, but it results in the person with the new powers killing their own mother. Not all scenes are shown, but the description is fairly clear, and could creep out younger viewers or could be nightmare inducing.
There are two birth scenes where you do not see anything, but the mother is screaming in pain. May frighten small children.
Scene in a cavern where two men attack a man who is more than their match.
During one of the episodes, a wolf attacks a group of men. The attack is off-camera, however the bloody aftermath of the attack is seen from a distance detailing bloody bodies and in one case a severed hand and several legs. There is A LOT of blood in this scene. Before we see this Red pulls a bucket of blood red water out of a well. Also during this episode a wolf eats a man alive. You can't see anything you can just hear growls and muffled screams. The wolf turns into a human and looks at the bloody aftermath of what had just happened. There is some flesh and a couple of bones in the distance for about a millisecond.
In another episode, A man is decapitated and his head is held by his hair. His body falls to the floor but his head is still moving. A lacerated wound around his neck is shown but not graphically bloody.
In episode 6, there is a dragon who burns the knights to death. There is one knight scene who looses his legs from the dragon, but is not killed. Mostly no blood, just skeletons and burns are seen.
In season 2 episode 7, a woman is impaled on a spike. You can clearly see the spike straight through her stomach, and there is a small amount of blood shown dripping from the wound. The woman dies. Also in this episode, you see a bloody body strewn along a road. It is revealed the man was murdered with an axe.
In season 2 episode 20, the aftermath of a massacre of an entire small village is seen. The bodies are piled on top of each other, and bodies of children are noticeable. They are not very bloody, however it can be upsetting.
In season 4 a woman falls off a cliff, there is a quick shot of her dead body down on the rocks.
The show does not feature scenes that focus in on gore and often violence is off screen, which keeps it at a more family friendly level. However, there are many characters, including main characters, who die.
Some scenes that are not bloody but could still be disturbing include scenes with "Wreaths" that suck people's soul out. Later, souls can be returned to the person, however. There are scenes of shadows being ripped away from people, or attempts to do so, which seems to result in a death. This is mostly done by Peter Pan and his shadow, which could be a little scary for younger children. However, it appears that once Pan is defeated, some of the shadows are returned to the person and they come back to life.
In season 4, Cruella's story can be quite intense. She gets the ability to control any animal and uses the ability to kill her mother. Someone comes in her room and she is seen sewing. He asks where the dogs are. She lifts the coat up to show it's made of their fur and says "they're with mother now."