Search Engine Journal

Like plural/ singular word forms, hyphenated terms also often pose a difficult SEO issues for us to solve - which version to use and optimize for: two-word, one-word or hyphenated one?

That question would be much easier to answer if Google demonstrated any definitive behavior when treating hyphenated terms; instead when using a hyphen in a search term, you will most likely see the mixture of hyphenated, single-word and two-word spelling variations. Thus I attempted to single out any types of patterns and ask you to also share your experience.

While the usage of a hyphen in compound words vary, grammatical rules that dictate the usage of the hyphen include:

• Differentiation between one-word, two-word or hyphenated variants is most often dictated by convention rather than fixed rules;
• Some prefixes (co-, pre-, mid-, de-, non-, anti-, etc.) are often hyphenated in British English and are often spelled as one word in American English;
• Compound verbs are usually hyphenated.

A few consistent search patterns I managed to sort out:

• hyphenated words are (generally) closer to two-word variant (Google just ignores the hyphen);
• hyphen doesn’t effect search results if one of the variant is grammatically correct (e.g. when hyphen means it’s a verb, search for hyphenated variant won’t return more verbal variants than for non-hyphenated ones);
• hyphenated words return all three variants: one-word, two-word and hyphenated ones;
• search results hyphenated words do not use bolding for stemming results (compare: [air-condition] and [air condition] and [aircondition]);
• two-word variants (or more correct per Google’s opinion) are more likely to be proceeded and followed by related terms suggested by Google;
• two-word and hyphenated variants tend to return more results even if one-word variant is considered to be proper use;
• top result is usually the same for all three variants.

Other points to note:

• Google trends tool treats all the three variants differently, so you can use it to differentiate between popular terms: [pre-school vs preschool vs pre school]

A few sample searches I analyzed: