However, by following this guide—extracting assets, rebuilding behavior JSON, and using GameTest scripts—you can port 60-80% of content-based Java mods to Bedrock. For the remaining 20% (core engine changes), you must accept that Bedrock works differently.
If you are searching for a website where you upload a .jar and download a .mcaddon —stop looking. It does not exist because the code languages are not compatible. convert jar to mcaddon work
Search for "Bedrock equivalent of [Mod Name]" before attempting a manual port. The community has likely already built an MCADDON that does what your JAR does. by following this guide—extracting assets
"format_version": "1.20.0", "minecraft:item": "components": "minecraft:on_hit": "fire": "duration": 5 rebuilding behavior JSON
Java Example: A sword that sets fire to enemies. Bedrock Version: Create my_sword.item.json and add: