It is not uncommon to encounter the terms ‘plaintext’ and ‘plain text’ used interchangeably, especially on the web. But which of the two is correct in the context of one’s everyday work – and especially on this website?

The term ‘plain text’, with a space in-between, refers to just that: a piece of content containing only text. That means no images, although some programmes exist that preview images for you, and no formatting, although some programmes exist that format your text for you on the fly. More appropriately, a file whose contents are stored as just a collection of text – alphabets, numbers and punctuation – is a plain text file.

The word ‘plaintext’ is a technical term most commonly used in cryptography and cryptanalysis to mean any content that is not obfuscated using a code or secret key. That is to say, text that is directly understandable, either to humans or through machines, without the aid of a key or other tool needed to ‘decode’ or ‘decrypt’ that content.

While in some case – such as the domain of this website – one has little choice but to use the word ‘plaintext’, it is generally recommended to use the term ‘plain text’ when referring to any piece of content written in the form of text and saved in straightforward, open and fundamental file formats which do not alter the text in any way, including across devices and/or servers.

Long story short, unless you are a cryptographer, prefer ‘plain text’ for your everyday work – and prefer plain text files as your first choice for working.