Is mapping from simplified to traditional characters injective (one-to-one function)?

Question

There is a plethora of online simplified to traditional characters converter like this one: https://www.chinese-tools.com/tools/converter-simptrad.html

Is it safe to use them? Won't it cause any mistakes in "translation"? My question boiles down to:

Is the mapping between traditional and simplified characters a one-to-one function? That is, does every simplified character only one traditional character equivalent?

If not, could you list the most prominent examples?

Answer 1

One simplified character may mapping to multiple traditional ones:

• 皇后 -> 皇后，後天 -> 后天
• 頭髮 -> 头发，發財 -> 发财

As reversed, one traditional character may mapping to multiple simplified ones too:

• 乾燥 -> 干燥，乾隆 -> 乾隆
• 瞭望 -> 瞭望，瞭解 -> 了解

This wikipedia article had discussed such thing for further reading: https://en.wikipedia.org/wiki/Ambiguities_in_Chinese_character_simplification

Answer 2

from traditional to simplified, it’s one-to-one.

however, from simplified to traditional, it’s a one-to-multiple

Is it safe to use them?

absolutely no

Won't it cause any mistakes in "translation"?

there’re enough mistakes that is, unsolvable without human recognition.

recently, i quoted the following example in another thread:

in traditional chinese, the terms “郁郁”, “鬰郁”, and “鬱鬱” are three distinguish words. unfortunately, there is only one term for them, in simplified chinese: “郁郁”.

such a sin

other common traps are (list items are in traditional chinese, not mixed):

• “乾”, “幹”, “干”
• “臺”, “檯”, “台”
• ”繫“, “係”, “系”
• “後”, “后”
• “發”, “髮”;
• “蕭”, “肖”

the list is long.

my sincere advice is: adhere to traditional chinese only.

Answer 3

There's a few answers and comments talking about ambiguities arising from mapping from Traditional (T) to Simplified (S). This isn't strictly true. The so-called ambiguous characters actually exist in Traditional Chinese, making the ambiguous mapping from T to S a spelling standardisation problem rather than a character set problem.

For example, 「干」 depicts a forked weapon, and is the only correct character for this sense. The fact that ROC decided to use 「乾」 for the meaning dry, collapsing it with the reading qián (sky, heaven), has no bearing on 「干」's existence in Traditional Chinese.

We can even compare Traditional Chinese using regions which standardise spelling differently. For example, the Taiwanese (ROC) spelling standard collapsed 「著」 and 「着」 both into 「著」, but Hong Kong did not.

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The reverse isn't true; 「後」 actually doesn't exist in Simplified Chinese. The PRC simultaneously conducted character form standardisation and spelling standardisation, blurring the concepts together.