I am using win10 can someone recommend me software that can convert mp3 to m4a.
M4a is the format for iphone, I want to install ringtones for my phone, my phone is not unlocked
Try TAudioConverter (https://www.fosshub.com/TAudioConverter.html).
A lot of members here are using foobar2000 as Converting-Frontend as it's often already in use for nearly everything.
Drop the files and rightmouseclick > Convert. As described you will have to add some binaries or pre-install the noted packages.
You might also check out BatchEncoder https://github.com/wieslawsoltes/BatchEncoder (https://github.com/wieslawsoltes/BatchEncoder) and especially this wiki-tutorial https://github.com/wieslawsoltes/BatchEncoder/wiki/Tutorial-Using-qaac-without-iTunes (https://github.com/wieslawsoltes/BatchEncoder/wiki/Tutorial-Using-qaac-without-iTunes) (based on qaac https://sites.google.com/site/qaacpage/home (https://sites.google.com/site/qaacpage/home)), presets are given but it's also about encoding-libraries.
Sure, not everything is an out-of-the-box-clickieclick-action-pack.
Oops, apparently, the entire topic was just an excuse to quote their opening post and edit in an advertisement link for search engine optimization.