When making use of AWS CloudFormation there is currently a file size limit of 51200 bytes on stack templates.
On a reasonable size setup you can quickly hit that limit using JSON format, while YAML format will take you a while longer. A quick example of a file size comparison between the two file formats;
stack.yaml - 3.3K stack.json - 5.6K
If you want to convert from JSON to YAML you can do that with the following python code snippet.
#!/env/bin python import json import yaml with open("stack.json") as fj: with open("stack.yaml", "w") as fy: yaml.dump(json.load(fj), fy)
Another option is to handle large stack templates is to make use of Transform