Translation guide
Describes a system or product that works with older versions or previous standards.
Expressing that a new version of software, hardware, or a standard can still work with older versions or data.
Standard technical term meaning 'has backward compatibility'. Used for software, hardware, and standards.
このソフトウェアは後方互換性があるので、古いファイルも開けます。
This software is backward compatible, so you can open old files.
Shorter, more direct way to say 'is backward compatible'. Common in product descriptions.
新バージョンは後方互換です。
The new version is backward compatible.
Literally 'has lower compatibility', often used interchangeably with 後方互換性. Slightly more common in some technical contexts.
この規格は下位互換性があるため、旧製品も使用可能です。
This standard is backward compatible, so older products can still be used.
More descriptive: 'compatible with old versions'. Useful when you want to be explicit.
このアプリは旧バージョンと互換性があるので、安心してアップデートできます。
This app is backward compatible, so you can update without worry.
Describing the act of ensuring backward compatibility during development.
Means 'to maintain backward compatibility'. Used when discussing design decisions.
開発チームは後方互換性を保つことに重点を置いた。
The development team focused on maintaining backward compatibility.
Means 'to ensure backward compatibility'. Slightly more formal.
新システムでは後方互換を確保する必要がある。
We need to ensure backward compatibility in the new system.
Both are widely used. 後方互換 (backward compatibility) is more literal, while 下位互換 (lower compatibility) is common in IT. In most contexts they are interchangeable, but 後方互換 is slightly more formal.