The various English dictionaries use different and sometimes conflicting IPA transcriptions for English. For example, the transcription /i/ may be used for the vowel of sit, of seat, or at the end of city. A dictionary may not even be consistent between one edition and the next. This table correlates these dictionaries with the conventions of the WP:IPA for English key that is used on Wikipedia.
Most dictionaries transcribe a specific dialect or accent, such as the Received Pronunciation (RP) of the Oxford English Dictionary, or a narrow range of dialects. Wikipedia's WP:IPA for English key, on the other hand, is intended to cover both RP and General American. As such, Wikipedia transcribes /r/ where it is found in rhotic dialects, but also the vowel distinctions found in non-rhotic dialects, without separating distinct UK and US pronunciations. Specific dialects may also be transcribed—local pronunciations of place names are often useful, for example—but they are normally written in addition to a more universal pronunciation.
When entering IPA in an article, please use the {{IPA}} template so that it is formatted properly on all web browsers. /Slashes/ and [brackets] should be included inside the IPA template, so that they display in the same font as the IPA itself. Also, please use proper stress: ˈ and length: ː marks (available at the bottom of your edit window) rather than the non-IPA shortcuts of apostrophe ' and colon :.
For a list of those languages other than English which have agreed-upon transcriptions in Wikipedia, see {{IPAhelp}}. For a comparison of the non-IPA transcriptions found in many US dictionaries, see Pronunciation respelling for English.
Consonants
Consonants vary little between dictionaries. The ones which do are those which start rich, /r ~ ɹ ~ ɻ ~ (r) ~ (ɹ)/; which, /ʍ ~ hw ~ (h)w ~ w/; and new, /njuː ~ nuː/. Wikipedia editors have decided to go with /ˈrɪtʃ/, /ˈhwɪtʃ/, /njuː/ for these words.