Kanji dictionaries are usually not sorted by reading. These are the dictionaries you will be using for looking up unknown or obscure kanji, not for looking up w

Kanji dictionaries are usually not sorted by reading. These are the dictionaries you will be using for looking up unknown or obscure kanji, not for looking up words (which may be composed of multiple kanji - or no kanji at all!). Since it is assumed that if you don't know the kanji, you also don't its reading, sorting this kind of dictionary by reading doesn't make sense. Besides, unlike in Chinese, most Japanese kanji have multiple (often many) different readings, sorting by reading just doesn't make sense. But besides Kanji dictionaries, most Japanese dictionaries (and other lists of words or name) are started by Gojūon (五十音), the standard sound order. If it is a specific word or name you're after, it generally has a distinct reading and it can by sorted by that reading.