The Known Keys

Anywhere Key

Power Description:  When this key is inserted into any door with a keyhole, the door becomes a portal to any other door in the world that the user can clearly visualize. 
Key Rediscovery:   Bode found the Anywhere Key in Kinsey's bracelet while in ghost form and concentrating on locating it.
Key History (modern):   Rendell bore the bracelet housing the Anywhere Key key during his high school days.  He later gave the Kinsey telling her "Believing in yourself is the key to being a complete person.  If you've got the key it can unlock any door and take you wherever you want to go."
First Appearance:   

• Locke & Key: Welcome to Lovecraft #1 (as Kinsey's bracelet)
• Locke & Key: Welcome to Lovecraft #6 (as key)

   

Echo Key

Power Description:  Allows the user to send things into empty places, whether its a voice or a physical object like a mirror or scissors. 
First Used:     Locke & Key: Welcome to Lovecraft #1 (though the key is not seen)
 
 
 
 
 
 
 

Gender Key

Power Description:  Allows a person to become the opposite of their current gender when this key is used with the Gender Changing Door.
Gender Key's Door:  The Gender Door is a half-sized door located in Kinsey's bedroom closet. 
Gender Key Possession:    The Lady in the Well has the key in her pouch.
First Appearance:  

• Locke & Key: Welcome to Lovecraft #2 (unseen but inside The Lady in the Well's leather neck pouch)
• Locke & Key: Welcome to Lovecraft #6 (as key)

 

Ghost Key 

   Power Description:  Allows the user to become a ghost when used in conjunction with the Ghost Door.  Upon passing through the doorway, a living creature's body will fall dead backwards onto the floor of Keyhouse (not forward through the door to the exterior of the house), but their spiritual essence will take on a ghostly form.  To return to life, the ghost must pass through the Ghost Door again in order to wake up in their body again.  If, however, the Ghost Door (with Ghost Key) is closed while the user is a ghost, they become a ghost permanently.
Upon becoming a ghost, the user gains other benefits not directly imparted by the key or door, but imparted by the nature of a ghostly essence.

• User is invisible and can't be heard.
• If water passes through the ghost, the water immediately becomes cold.
• Ability to 'flash' (teleport) to a specific person, location, or object if the ghost thinks about it, even if the ghost doesn't know where the target is located.
• If someone thinks of the ghostly user, the ghost may be flashed (teleported) to their location.

Ghost Key's Door:  The Ghost Door is an exterior facing door located on the East side (or East elevation) of Keyhouse.
Key Rediscovery:   Bode found the key on top of the Ghost Door's door frame.  
First Appearance:   Locke & Key: Welcome to Lovecraft #1 
First Used:   Locke & Key: Welcome to Lovecraft #1 
 
 

Giant Key

Power Description:  Increases the user's size to giant proportions. 
 
 
 
 
 
 
 

 

Head Key

Power Description:  Allows the user to open their head (as if the top of the cranium were a lid) so that items/objects can be inserted or removed from the users mind after inserting the key into a magically appearing keyhole in the back of their neck. 
Key Rediscovery:   Bode found the key  in the cement pond near Keyhouse's well-house when fishing with his magnetic fishing rod.
First Appearance:    Locke & Key: Welcome to Lovecraft #6
 
 
  
 
 

Mending Key

Power Description:  Used to fix broken objects.

 
 
 
 
 
 
 

Omega Key

Power Description:  Unknown, but it opens the Black Door
Omega Key's Door:  The Black Door

First Indirect Appearance: 

• Locke & Key: Welcome to Lovecraft #1 (unseen but in Rendell's red urn)     

 
 
 
 
 
 
 

Shadow Key

Power Description:  Brings shadows to life.
 
 
 
 
 
 
 
 
 

Undefined Keys

Hourglass Key

Power Description:  Unknown, but presumably it controls or alters time when used in conjunction with the grandfather clock it sits upon.
 
 
 
 
 
 
 
 
  
 

Age Key 

Power Description:   The Lady in the Well asks of Bode "Want to be a grow-up?  There's one (door) that will turn you into an old person when you walk through it."  Whether the user can choose any other age is currently unknown.
First Mentioned:   Locke & Key: Welcome to Lovecraft #2 
 
 

Theoretical Keys, Locks, or Doors

Tyler's Fishing Lure    

Reasoning:   Rendell gave it to him with a very oddly phrased message about its importance.   Tyler wears it on his baseball cap.   Rendell also gave the Anywhere Key to Kinsey so perhaps all the Locke children have secretly been given a key.