によると details

Examples

according to; based on — names the source a piece of information comes from, usually paired with a hearsay or appearance tail

占うらないによると、今日きょうはラッキーカラーが赤あからしいよ。

uranai ni yoru to, kyou wa rakkii karaa ga aka rashii yo.

According to the horoscope, today's lucky color is apparently red. casual

天気予報てんきよほうによると、明日あしたは晴はれるそうだ。

tenkiyohou ni yoru to, ashita wa hareru sou da.

According to the weather forecast, it will be sunny tomorrow. neutral

発表はっぴょうによれば、今年度こんねんどの売うり上あげは前年比ぜんねんひ十じゅっパーセント増ぞうとのことです。

happyou ni yoreba, konnendo no uriage wa zennenhi juppaasento zou to no koto desu.

According to the announcement, this year's sales are reportedly up ten percent year-on-year. formal

Almost always resolves in a hearsay or appearance tail (そうだ、とのことだ、
らしい) — bare Nによると with nothing following sounds unfinished.

そうだ
Both mark secondhand information, but によると explicitly names the SOURCE the claim traces back to (天気予報によると), while そうだ alone can relay hearsay with no source ever named — によると is source-first, そうだ is content-first.

によって
Both are built on the verb 因[よ]る, but によって marks an agent, means, or cause acting ON something (作家によって書かれた), while によると/によれば frames the clause as reported information, usually with そうだ/とのことだ — it never marks a passive agent.

そうだ
The two stack into the standard reportage frame, Nによると・Xそうだ, with によると naming the source and そうだ carrying the relayed claim plus its own tense and polarity.