Type H vs Type O Plugs: Pin Design Differences & Compatibility

Type H is a 3-pin, grounded plug rated 16A at 220-240V, while Type O is a 3-pin, grounded plug rated 16A at 220-240V. The two differ mainly in pin design, which is what decides compatibility — whether a Type H plug fits a Type O socket, and vice versa. Compare this with type E vs type H plug.

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Type H power plug and wall socket
Type H
Type O power plug and wall socket
Type O
Standard SI 32 TIS 166-2549
Pin Configuration Three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length) Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)
Grounding Grounded Grounded
Pin Count 3 3
Amperage 16A 16A
Voltage Range 220-240V 220-240V

Key Differences Between Type H and Type O

Here's how Type H and Type O compare, point by point.

  • Grounding: Both Type H and Type O are grounded.
  • Pin Size and Shape: Type H: Three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length). Type O: Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin).
  • Application: Type H is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters. Type O is typically used for heavy-duty appliances such as hair dryers, kettles, and heaters.

Type H and Type O Compatibility

Type H in Type O Sockets: Generally no. A Type H plug (Three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length)) does not fit a Type O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter. Compare this with type C vs type H plug.

Type O in Type H Sockets: Generally no. A Type O plug (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) does not fit a Type H socket (Three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length)) without a travel adapter.

If you're planning a trip, tell us which country you're visiting and we can confirm whether you need a Type H or Type O travel adapter.

Does a Type H plug fit into a Type O socket?

Generally no. A Type H plug (Three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length)) does not fit a Type O socket (Three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin)) without a travel adapter.

Are Type H and Type O plugs the same?

No. Type H follows the SI 32 standard and Type O follows TIS 166-2549 — they differ in pin design. Next, check is type C compatible with type N.

Which countries use Type H and Type O plugs?

Type H plugs are used in 3 countries, including Gaza Strip, Israel, Palestine. Type O plugs are used in 1 countries, including Thailand.

How can you tell a Type H plug from a Type O plug?

A Type H plug has three pins in V-shape arrangement (round 4.5mm or flat pins, 19mm length), and is grounded. A Type O plug has three round pins in triangular pattern (4.8mm diameter power pins, 4mm grounding pin), and is grounded. The quickest tell is pin size and spacing — compare the two pin configurations above.