---
title: "BIP39 Word #51: alien — Seed Phrase Mnemonic Word"
url: "https://bip39-phrase.com/bip39-word/alien/"
language: "en"
updated: "2026-10-19T00:00:00+00:00"
---

Word #51 00000110010 

# alien — BIP39 word #51

"**alien**" is word #51 of the 2048 words in the official BIP39 English wordlist, between [alert](/bip39-word/alert/) and [all](/bip39-word/all/). In a seed phrase it stands for the 11-bit value `00000110010`, decimal index 50\. 

/ˈeɪliən/  · _noun:_ a creature from another planet, or a person from another country 

[Russian](/ru/ "The BIP39 wordlist with Russian translations"): пришелец 

## Binary Representation

Three 1-bits and eight 0-bits; 165 of the 2048 indexes have exactly three 1-bits.

One wrong bit turns it into (leftmost bit first):

[main](/bip39-word/main/)[edge](/bip39-word/edge/)[chaos](/bip39-word/chaos/)[bind](/bip39-word/bind/)[atom](/bip39-word/atom/)[across](/bip39-word/across/)[affair](/bip39-word/affair/)[also](/bip39-word/also/)[almost](/bip39-word/almost/)[alcohol](/bip39-word/alcohol/)[all](/bip39-word/all/) 

Position

Hex Index

0x032

4-Letter Prefix

alie

## About "alien" in BIP39

- "alien" has 5 letters, but the first three, **"ali"**, already identify it, because **"al"** also begins 14 other words, among them [alarm](/bip39-word/alarm/), [album](/bip39-word/album/), [alcohol](/bip39-word/alcohol/) and [alert](/bip39-word/alert/). Three letters are enough for only 604 of the 2048 words.
- **"alie"** is unique only within the English list: it also begins aliento in the [Spanish list](/spanish/) and alienar in the [Portuguese list](/portuguese/), so a four-letter backup should say which list it uses.
- "alien" appears in one of the 24 official English [test vectors](https://github.com/trezor/python-mnemonic/blob/master/vectors.json) of BIP39: vector #21 (word 8 of 24). Every official vector passes the [checksum checker](/bip39-checksum-checker/), and [How BIP39 works](/how-bip39-works/) shows how the entropy turns into such words.

Official test vector #21

[all](/bip39-word/all/) [hour](/bip39-word/hour/) [make](/bip39-word/make/) [first](/bip39-word/first/) [leader](/bip39-word/leader/) [extend](/bip39-word/extend/) [hole](/bip39-word/hole/) alien [behind](/bip39-word/behind/) [guard](/bip39-word/guard/) [gospel](/bip39-word/gospel/) [lava](/bip39-word/lava/) [path](/bip39-word/path/) [output](/bip39-word/output/) [census](/bip39-word/census/) [museum](/bip39-word/museum/) [junior](/bip39-word/junior/) [mass](/bip39-word/mass/) [reopen](/bip39-word/reopen/) [famous](/bip39-word/famous/) [sing](/bip39-word/sing/) [advance](/bip39-word/advance/) [salt](/bip39-word/salt/) [reform](/bip39-word/reform/) 

## Word #51 in the Other 9 BIP39 Wordlists

[Czech](/czech/) batoh 

[French](/french/) adulte 

[Italian](/italian/) alce 

[Japanese](/japanese/) あんこ 

[Korean](/korean/) 같이 

[Portuguese](/portuguese/) aditivo 

[Spanish](/spanish/) agudo 

[Traditional Chinese](/chinese-traditional/) 面 

[Simplified Chinese](/chinese-simplified/) 面 

## More BIP39 Words Starting with "A"

[ #47 alarm ](/bip39-word/alarm/)[ #48 album ](/bip39-word/album/)[ #49 alcohol ](/bip39-word/alcohol/)[ #50 alert ](/bip39-word/alert/)[ #52 all ](/bip39-word/all/)[ #53 alley ](/bip39-word/alley/)[ #54 allow ](/bip39-word/allow/)[ #55 almost ](/bip39-word/almost/) 

[View all words starting with "A" ](/bip39-words/a/) 

## Seed phrase, key and recovery guides

- [Private Key Export: MetaMask, Trust Wallet, Ledger, Electrum](/convert-seed-phrase-to-private-key-guide/)
- [How to Create a Seed Phrase: Step-by-Step Guide and Examples](/create-a-seed-phrase/)
- [BIP 44 – Multi-Account Hierarchy for Deterministic Wallets](/bip-44-multi-account-hierarchy-for-deterministic-wallets/)

[ Full BIP39 Wordlist ](/)