Superscript One

A small raised 1: footnote number one, or "to the power of one". A common place to meet it is at the end of a sentence, after a name or after a price: "Free shipping on all orders¹". It points to note 1, printed at the foot of the page, the end of the chapter, or in the small print of an advert. In many English styles the marker sits right after the comma or full stop with no space before it, and the next note gets 2, then 3.

In maths ¹ is an exponent. x¹ means x raised to the first power, which is x itself, so writers normally leave it out; it turns up when a pattern is being shown (x¹, x², x³) or in units such as m·s⁻¹. In chemistry and physics a raised number in front of an element symbol is the mass number: ¹H is the common isotope of hydrogen, ¹⁴C is carbon-14, the isotope used for dating.

Outside print and science, superscript digits do two small jobs. Typed with the fraction slash they make a tidy one-line fraction, ¹⁄₂ or ¹⁄₃. And together with superscript letters they produce the ᵗⁱⁿʸ-looking text some people put in usernames, bios and captions; there the 1 means nothing beyond looking small.

Is ¹ the same as a 1 formatted as superscript?

No. ¹ is a separate character; formatting only raises an ordinary 1. When a word processor makes a 1 superscript, the text still contains a plain 1 with a style attached. Paste it into a chat, a filename, an email subject or a social-media post, places that keep only plain text, and the style falls away, leaving a full-size 1. ¹ carries its own raised shape, so it stays raised wherever the font has it. That is why people use it in plain-text places and why the Word footnote tool, which inserts formatted numbers and links them to notes, is not the same thing as typing ¹ by hand.

The flip side: Unicode records ¹ as a compatibility form of 1, so software that applies compatibility matching treats the two as equal and other software does not. A name that differs only by a raised digit is therefore not a safe way to tell two things apart.