How to validate cloudformation templates on your computer?

Even before I get to the point of letting AWS validate my templates, I usually run them through a local de-linter. Either jq or Python's json.tool module works a trick:

• jq --exit-status . <FILENAME>
• python -m json.tool <FILENAME>

Takes care of basic syntax checking. Both also work well inside a CI testing-rule (e.g., a .travis.yml file). Which means you can set up a git-trigger to only allow a branch-merge when a basic syntax check passes.