b2tob3 is a command line tool to help migrate Web projects from bootstrap 2 to bootstrap 3 by performing a set of replacements that reflect bootstrap 3 class name changes.

b2tob3 searches all files ending in .html, .htm, .css or .js in the current directory and its subdirectories. You can specify the working directory with the d option like b2tob3 -d /path/to/dir.

b2tob3 does not fully automate migration, but it takes away some of the tedious work. Still, you'll most likely need to perform manual fixes too.

pip install b2tob3

cd /project/html/
b2tob3

• Put your HTML/template files under version control, if they aren't yet.
• Change to the directory with the files containing Boostrap 2 specific markup.
• Run the b2tob3 script once and only once.
• Review the changes with a diff tool suitable for the version control system you use.
• Perform the rest of the necessary changes manually.

• Let me know about bugs by posting an issue.
• Help reduce the manual work by improving the code.
• Write tests.

Thanks to @demiurg for adding more robust replacements and command line options.