了解です

• Reading: りょうかいです
• Romaji: ryokai desu
• Kanji breakdown: 了 (complete/finish) + 解 (understand) → comprehension, understanding
• Pronunciation: /ɾʲoː.ka.i de.sɯ/

Meaning

A quick 'understood' or 'roger that,' widely used in workplace and casual texting to confirm receipt of information.

了解です is a standard acknowledgment in Japanese texting and workplace chat. While 了解 alone can sound curt, adding です softens it just enough for most situations. However, there's an ongoing debate about whether 了解 is appropriate to use with superiors (some manners guides say use 承知しました instead), though in practice most people use it freely in chat apps like Slack and LINE.

Examples

1. 「明日10時集合ね」「了解です！」 Meet at 10 tomorrow, okay?' 'Got it!
2. 了解です、すぐ対応します。 Understood, I'll handle it right away.
3. 了解です〜、ありがとうございます。 Got it~ thank you.

Usage Guide

Context: texting, workplace chat, LINE, email

Tone: businesslike, efficient

Do Say

• 了解です、15時までに提出します (Understood, I'll submit it by 3 PM)
• 了解です！準備しておきます (Roger that! I'll get it ready)

Don't Say

• 厳格な上司への返信では「承知しました」が無難 (For strictly hierarchical bosses, 承知しました is safer — some consider 了解 to be peer-level language)

Common Mistakes

• Using 了解 without です to superiors, which sounds too blunt
• Not knowing that some Japanese business etiquette guides consider 了解 inappropriate for use with superiors

Origin & History

了解 (ryoukai) means 'comprehension/understanding' and has been used in Japanese communication for a long time. The casual texting form 了解です became ubiquitous with the rise of workplace messaging apps. The abbreviation りょ (ryo) or り (ri) are even more casual variants.

Cultural Context

Era: 2000s workplace messaging culture

Generation: All ages

Social background: Universal

Regional notes: Used across all of Japan. The debate over 了解 vs. 承知 for superiors is well-known but not universally followed.