= AspectJ Java version compatibility For reasons described e.g. in https://github.com/eclipse-aspectj/aspectj/issues/139#issuecomment-1072946123[this comment], for AspectJ users it has become a little challenging to find out which minimum AspectJ version is required in order to process byte code or compile source code using features of a certain Java language version. Since Java 10, this cannot be easily concluded from the AspectJ version number anymore, and we are sorry for that. So here is a little overview: [%autowidth, stripes=even, options="header"] |=== |AspectJ version |Java version |Comments |1.9.21 |21 |AspectJ compiler requires JDK 17+ during build time. During runtime, AspectJ still only requires Java 8+ for both compile-time and load-time weaving. Pure Java code can be compiled down to as old as 1.3 byte code level. |1.9.20 - 1.9.20.1 |20 | |1.9.19 |19 | |1.9.9 - 1.9.9.1 |18 | |1.9.8 |17 |AspectJ compiler requires JDK 11+ during build time. During runtime, AspectJ still only requires Java 8+ for both compile-time and load-time weaving. Pure Java code can be compiled down to as old as 1.3 byte code level. |1.9.7 |15, 16 | |1.9.6 |14 | |1.9.5 |13 | |1.9.3 - 1.9.4 |12 | |1.9.2 |11 | |1.9.1 |10 | |1.9.0 |9 | |1.8.0 - 1.8.14 |8 | |1.7.0 - 1.7.4 |7 | |1.6.0 - 1.6.12 |6 | |1.5.0 - 1.5.4 |5 | |=== Older versions omitted. FYI, here is a brief overview of https://docs.oracle.com/en/java/javase/18/language/java-language-changes.html[Java language changes since Java 9]. They basically correspond to the new Java language features supported by AspectJ versions for the respective Java versions.