The wave dash (〜): copy it, type it, tell it apart

The wave dash is the tilde’s Japanese cousin — the character in 1990年〜2000年 (from 1990 to 2000), in 3000円〜 (from 3,000 yen upward), and in the drawn-out そう〜 of casual messaging. It is also one of the great encoding traps of CJK computing, because two different characters claim the job: Unicode’s wave dash (U+301C) and the fullwidth tilde (U+FF5E) that Windows shifted to decades ago in its Shift-JIS lineage. The two look nearly identical, and converting between encodings has corrupted more 〜 characters than any other single CJK code point.

The practical upshot: text typed on a Japanese Windows machine usually holds U+FF5E; text typed on macOS usually holds U+301C; and a database, search engine or validator that accepts one will often reject the other. Copy the character you actually need from the cards above — the big button carries the Unicode wave dash, the grid gives you all four relatives — and if a paste renders as a box or a question mark, you have met the wrong one for that font.

The other two relatives matter outside Japanese. The swung dash (U+2053) is the dictionary mark that repeats a headword, and the ASCII tilde (~) is the keyboard original that every URL, shell command and approximation has used since the 1960s. All four are real Unicode characters, not images, and each carries its own code point below so you can verify exactly which one you pasted.