American and British English spelling differences

British and American spellings around the world:

  British *analyse/crystallise* (*crystallize* in Oxford spelling)*/centre/defence/labour/programme* (except for *computer program*) dominant; English is an official or majority language

  American *analyze/crystallize* (less commonly *crystalize*)*/center* (except for some place names, e.g. *Centre County*)*/defense/labor* (except for some names, e.g. *Living Colour*)*/program* dominant; English is an official or majority language

  Canadian *analyze/crystallize/centre/defence/labour/program* dominant; English is one of two official languages along with French

  Australian *analyse/crystallise/centre/defence/labour* (except for *Labor Party*)*/program* dominant; English is an official or majority language

  English is not an official or majority language; British spelling is dominant

  English is not an official or majority language; American spelling is dominant

  English is not an official or majority language; inconsistent use of American and British spelling

Despite the various English dialects spoken from country to country and within different regions of the same country, there are only slight regional variations in English orthography, the two most notable variations being British and American spelling. Many of the differences between American and British or Commonwealth English date back to a time before spelling standards were developed. For instance, some spellings seen as "American" were once commonly used in the United Kingdom, and some spellings seen as "British" were once commonly used in the United States.

A "British standard" began to emerge following the 1755 publication of Samuel Johnson's A Dictionary of the English Language, and an "American standard" started following the work of Noah Webster and, in particular, his An American Dictionary of the English Language, first published in 1828. Webster's efforts at spelling reform were effective in his native country, resulting in certain well-known patterns of spelling differences between the American and British varieties of English.