Cipher or cypher?
cipher is a noun meaning “A method of transforming a text in order to conceal its meaning”; cypher is a noun meaning “Alternative spelling of cipher”. Wiktionary gives them as spellings of the same word. In written English (wordfreq, 2021 data) cipher is about 2.1 times as common as cypher.
What is the difference between cipher and cypher?
| cipher | cypher | |
|---|---|---|
| Part of speech | noun, verb | noun, verb |
| Meaning | A method of transforming a text in order to conceal its meaning A cryptographic system using an algorithm that converts letters or sequences of bits into ciphertext To write in code or cipher | UKAlternative spelling of cipher |
| Example | a painter's cipher | none recorded |
| Forms | ciphers | cyphers |
| Pronunciation | /ˈsaɪfə/ /ˈsaɪfɚ/ | not recorded |
| In writing | 1.3 times per million words | about once in every 2 million words |
Sources: cipher and cypher in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of cipher and cypher
cipher
- 1
datedA numeric character
- 2
datedTo calculate
I never learned much more than how to read and cipher
- 3
A method of transforming a text in order to conceal its meaning
The message was written in a simple cipher. Anyone could figure it out
- 4
To write in code or cipher
- 5
A cryptographic system using an algorithm that converts letters or sequences of bits into ciphertext
a public-key cipher
- 6
Of an organ pipe: to sound independent of the organ
- 7
Ciphertext; a message concealed via a cipher
The message is clearly a cipher, but I can't figure it out
- 8
A fault in an organ valve which causes a pipe to sound continuously without the key having been pressed
cypher
- 1
UKAlternative spelling of cipher
- 2
UKAlternative spelling of cipher
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, cipher or cypher?
cipher appears 1.3 times per million words; cypher about once in every 2 million words.
cipher 1.3 times per million wordscypher about once in every 2 million words
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How many people search cipher vs cypher?
“cipher vs cypher” is searched about 390 times a month on Google and 20 on Bing in the United States. Google counts close variants of a query together (“cypher vs cipher”, “cipher or cypher”).
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026.