What is the key for guitar without a capo?

The key for guitar without a capo is the open key or standard tuning. The standard tuning for a six-string guitar is EADGBE (low to high strings). This means that the thickest string is tuned to E, the next string is tuned to A, the third string is tuned to D, the fourth string is tuned to G, the fifth string is tuned to B, and the thinnest string is tuned to high E.