Translation guide
The ability of a newer system or version to work with older data, software, or hardware. In Japanese, this is most commonly expressed with the borrowed term 下位互換性, but other patterns exist depending on context.
Expressing that a new version or system can handle older formats, data, or devices.
The standard technical term for downward compatibility. Used in software, hardware, and standards contexts.
このソフトウェアは下位互換性があります。
This software has downward compatibility.
下位互換性を保つために、古いフォーマットもサポートしています。
To maintain downward compatibility, we also support older formats.
A shorter form of 下位互換性, often used in compound nouns or casual technical discussion.
このプリンターは下位互換モードで動作します。
This printer operates in downward compatibility mode.
Literally 'backward compatibility'. Sometimes used interchangeably with 下位互換性, but can also imply compatibility with previous generations in a broader sense. Less common in everyday tech contexts.
このゲーム機は後方互換性を備えています。
This game console has backward compatibility.
Describing a product or system as being downward compatible.
A common way to say 'has downward compatibility'.
このアプリは下位互換があるので、古いOSでも使えます。
This app has downward compatibility, so you can use it on older OSes.
Means 'to maintain downward compatibility'. Often used when discussing design decisions.
新しいバージョンでも下位互換性を保っています。
The new version still maintains downward compatibility.
Saying that something supports or is compatible with older things.
A natural way to say 'supports older X'. Replace ～ with the specific item.
このソフトは古いファイル形式に対応しています。
This software supports older file formats.
新しいプリンターは古いインクカートリッジに対応していません。
The new printer doesn't support older ink cartridges.
Literally 'has compatibility with old versions'. A clear and direct expression.
このデータベースは旧バージョンと互換性があります。
This database is compatible with older versions.
Both translate to 'downward compatibility' or 'backward compatibility'. 下位互換性 is more common in IT and consumer electronics. 後方互換性 is sometimes used in broader engineering contexts, but they are largely interchangeable. For most learners, 下位互換性 is the safer choice.
In everyday speech, it's often more natural to say ～に対応している (supports ~) rather than using the technical term 互換性. For example, 'This app is downward compatible' can be simply このアプリは古いバージョンに対応しています.