I tried to upgrade Spring Tool Suite version from 3.9.9 to latest version (4.5.1) but i am not find the latest upgrade version.
I have checked existing STS IDE on help- >Check for Updates options, its having only STS 3 updates only i'm not found any STS 4 version update.
Currently i am using STS 3 only, instead of downloading and installing new STS 4 version is there any option for upgrade 3.x version 4.x.?
Upgrading an existing installation from Spring Tool Suite 3.x to Spring Tools 4 is not supported and not recommended.
It might be possible, but it would involve manually uninstalling specific features and installing others for the corresponding Eclipse platform version. I would strongly recommend to not go down that path and start with a fresh Spring Tools 4 installation instead. If you have additional third-party plugins installed in your old STS3 install that you would like to get back into your new Spring Tools 4 install, there is support for that via the Import wizard in Eclipse (Import... -> Install -> From Existing Installation), but you need to carefully select the features that you would like to carry over.
