に応じて|におうじて

1. 1Something is adjusted or varies to suit a changing factor (in accordance with, depending on, in proportion to).Ex. 1
2. 2Acting in response to a request, demand or invitation, including a single specific one (e.g. 彼の依頼に応じて資料を送った).Ex. 3

Common in business, administrative and explanatory contexts, such as fees, taxes, services and plans adjusted to fit conditions. In sense 1 the noun names a varying factor (人数, 収入, 年齢, 状況). In sense 2 it names a request or demand (依頼, 要望), which may be a single one. It is neutral to slightly formal. Unlike に基づいて, which names a basis, it stresses adapting to something.

• 1.
  に従ってN3「に従って」: when it means 'as something changes,' the latter item changes gradually along with the former, while 「に応じて」 focuses on adjusting in proportion to amount or degree. When it means 'in accordance with,' it implies obeying rules or instructions, unlike responding to an invitation. It can also attach to a verb in dictionary form.
• 2.
  に基づいてN2「に基づいて」: uses data, facts, or laws as a basis, with the latter item faithfully following that basis, and is rather formal; 「に応じて」 adjusts according to the amount or situation of the former item and also has a 'respond' meaning. When simply basing something on rules or materials, 「に応じて」 is not used.
• 3.
  次第だ / 次第でN2「次第だ／次第で」: emphasizes that the outcome depends entirely on the former item and is still undetermined, and can also take an interrogative clause; 「に応じて」 emphasizes that the latter item adjusts appropriately to the former. 「次第」 has no 'respond' meaning, so the two are generally not interchangeable.
• 4.
  によって / によるN3「によって」: when expressing variation, the latter item is often 「異なる」 or similar, focusing on pointing out differences; 「に応じて」 focuses on adjusting accordingly. 「によって」 also expresses cause, means, or the passive agent; 「に応じて」 additionally has a 'respond' meaning.
• 5.
  に伴ってN2「に伴って」: indicates that the latter item occurs alongside a change or event in the former, without emphasizing proportionality to the former and with no 'respond' meaning; it attaches to nouns and verbs and is rather formal. 「に応じて」 attaches only to nouns and is neutral in register.

に応じて means adjusting something to fit a varying factor or responding to a request. に従って means following rules or instructions, or marks a proportional change ('as X, Y'); に伴って marks a change that accompanies another change; に基づいて names a basis or source; 次第で stresses that an outcome hinges entirely on X; and によって broadly marks variation by case, as well as means or cause.