<p>Taproot outputs contain <em>x-only</em> (tweaked) public keys. Due to the lack of Y coordinates, the number of valid keys is halved.</p>
<p>The exact number of possible x-only keys is <em>2<sup>255</sup> - 216210193282829828426210433197484072800</em>.</p>

CC BY-SA 4.0
2022-12-10T21:58:32.460Z
The other half can still be made into valid SegWit v1 outputs (and therefore addresses), even though they would not be spendable, right?
Vojtěch Strnad
CC BY-SA 4.0
2022-12-10T22:09:43.557Z
That's right. The address format can encode X coordinates that don't have corresponding public keys, but any coins sent to such an output are irrevocably lost.
Pieter Wuille
CC BY-SA 4.0
2022-12-10T20:39:26.213Z
2022-12-10T20:39:26.213Z
Pieter Wuille
<p>Given that Taproot (SegWit v1) addresses are basically equivalent to a public key -- does that mean that there are a full 2<sup>256</sup> possibilities?  Or is the overall number of possible addresses reduced in some way?</p>

<address-generation><taproot><bech32-address>
How many unique Taproot addresses (eg pubkeys) are possible?
Jonathan Cross
# How many unique Taproot addresses (eg pubkeys) are possible?

(Asked by: username_0 on 2022-12-10)

Given that Taproot (SegWit v1) addresses are basically equivalent to a public key -- does that mean that there are a full 2256 possibilities? Or is the overall number of possible addresses reduced in some way?

**Tags:** address-generation, taproot, bech32-address


---

## 1 answers

### Answer by username_1 on 2022-12-10. Score: 1 | Accepted answer

Taproot outputs contain *x-only* (tweaked) public keys. Due to the lack of Y coordinates, the number of valid keys is halved.

The exact number of possible x-only keys is *2255 - 216210193282829828426210433197484072800*.

> **Comments:**
> **username_2**: The other half can still be made into valid SegWit v1 outputs (and therefore addresses), even though they would not be spendable, right?  
> **username_1**: That's right. The address format can encode X coordinates that don't have corresponding public keys, but any coins sent to such an output are irrevocably lost.  

---

