<p>The <a href="https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#user-content-Serialization_format" rel="nofollow noreferrer">xprv format</a> contains some metadata about the key it contains.</p>
<p>Part of that metadata is what level from the root it is (an xprv can be derived from another xprv, incrementing the level by one). Another piece of metadata is what the (32 bit) fingerprint of the parent it is derived from, if any.</p>
<p>Root xprvs (those directly derived from a seed) have level 0, and parent fingerprint 00000000. When converting to base58 format, those 5 bytes for level + fingerprint translate to a fixed string.</p>

CC BY-SA 4.0
2023-06-21T06:03:46.333Z
Thank you, that makes sense now! Particularly the part about the default parent fingerprint value being 00000000 for every master key pair... thx
bitguy54
CC BY-SA 4.0
2023-06-20T23:35:44.500Z
2023-06-20T23:48:10.407Z
2023-06-20T23:48:10.407Z
Pieter Wuille
<p>the prefix <code>xprv9s21ZrQH143K...</code>? no matter which seed phrase I start from.
whereas normal private keys will vary totally.</p>
<p>What does the &quot;...9s21ZrQH143K...&quot; mean?
Further, this sequence will sometimes be followed by a 3 or a 4, but often times it's a 2 before continuing the rest of the string.</p>
<p>I searched all over the web and couldn't find an answer.</p>

<bip32-hd-wallets><deterministic-wallets>
Why do bip32 (HD Wallet) xprv key strings all start with
bitguy54
# Why do bip32 (HD Wallet) xprv key strings all start with

(Asked by: username_0 on 2023-06-20)

the prefix `xprv9s21ZrQH143K...`? no matter which seed phrase I start from.
whereas normal private keys will vary totally.

What does the "...9s21ZrQH143K..." mean?
Further, this sequence will sometimes be followed by a 3 or a 4, but often times it's a 2 before continuing the rest of the string.

I searched all over the web and couldn't find an answer.

**Tags:** bip32-hd-wallets, deterministic-wallets


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## 1 answers

### Answer by username_1 on 2023-06-20. Score: 1 | Accepted answer

The [xprv format](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#user-content-Serialization_format) contains some metadata about the key it contains.

Part of that metadata is what level from the root it is (an xprv can be derived from another xprv, incrementing the level by one). Another piece of metadata is what the (32 bit) fingerprint of the parent it is derived from, if any.

Root xprvs (those directly derived from a seed) have level 0, and parent fingerprint 00000000. When converting to base58 format, those 5 bytes for level + fingerprint translate to a fixed string.

> **Comments:**
> **username_0**: Thank you, that makes sense now! Particularly the part about the default parent fingerprint value being 00000000 for every master key pair... thx  

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