What Is a Diacritic?

A diacritic is a mark attached to a letter that changes how it is pronounced, stressed or understood. Examples: the acute in é, the tilde in ñ, the umlaut in ü, the cedilla in ç, the circumflex in ô, the caron in š and the ring in å. The word comes from the Greek diakritikos, “able to distinguish”. Diacritics are used in many writing systems besides Latin, including Greek, Cyrillic, Arabic, Hebrew and Indic scripts.

Diacritics and meaning

Diacritics are not decoration in most languages that use them. In Spanish papa means “potato” and papá means “dad”; in French côte and côté are different words; in Vietnamese stacks of marks on one vowel give it a tone. In English, diacritics are rare and mostly in loanwords such as café, naïve and jalapeño, but they remain part of the spelling.

Precomposed and combining forms in Unicode

Unicode lets you encode an accented letter in two ways:

Both display the same and are defined as canonically equivalent, but their data differ: one is one character and the other is two. Software that needs to compare strings uses normalisation (NFC composes, NFD decomposes) so that the two forms match. This is why a search for “café” can fail on text typed in the other form if software does not normalise.

The Combining Diacritical Marks block (U+0300 to U+036F) holds the common combining accents. When one follows a letter, the rendering engine, using the font’s mark positioning tables, places it above, below or through the base letter, taking into account the ascender height and baseline to avoid collisions.

The fancy-text tricks that are really diacritics

Several generators on this site use combining marks, not special alphabets:

• Strikethrough adds U+0336 (COMBINING LONG STROKE OVERLAY) after each letter. See the strikethrough text generator.
• Underline uses U+0332 (COMBINING LOW LINE), and double underline uses U+0333.
• Zalgo or glitch text stacks many marks above and below each letter, like a “creepy” cloud: the glitch text generator.
• Tilde-strike, cross-above and arrow-below use other marks from the same block, as in the text decorator.

Because the base letters remain, text like this survives copy and paste and can be reversed. Our unstyle text tool strips the marks and returns the plain letters. The downside is rendering: the number of marks a font draws before it stops varies, some apps clip them to the line height, and screen readers can read each mark, which makes the text noisy, as covered in fancy text accessibility. Platforms sometimes limit consecutive combining marks to protect their layouts. Our how fancy text works guide gives the broader picture.

A glyph is not the same as a character here either: a letter plus several marks is several characters but may be shown as a single cluster, called a grapheme cluster, which is what a user perceives as one letter.

Diacritics in lettering and handwriting

In handwriting, a diacritic is a separate small stroke added after the word is complete, like the dot over an i or the cross of a t. Teachers recommend adding them last, in a single pass, so the flow of a word is not interrupted. In hand lettering, diacritics need space: accents on capitals such as É and Ö rise above the cap height, so line spacing must be generous or the marks collide with the line above. This is the cause of most “tight leading” problems in lettering for languages such as French, Vietnamese and Czech.

Common confusions

• A diacritic is not a letter. In some languages, though, ñ, ö or å count as separate letters in the alphabet and in sorting.
• An umlaut is not a diaeresis in meaning, although both look like two dots: the diaeresis (naïve) marks a separate syllable, while the umlaut (Müller) marks a changed vowel. In Unicode both are the same mark, U+0308.
• Combining marks are not styles. They add to letters; they do not replace them with a different alphabet.