The difference is purely syntactical. Most modern frameworks prefer the former ( env.production.local ), but legacy systems or custom CI/CD pipelines might recognize the latter. If you have .env and .env.production , why introduce a third file? The answer lies in sensitive, environment-specific configuration .

Audit your environment loading logic today. Does your framework recognize .env.local.production ? If not, you may be chasing bugs that don't exist. If yes, use it wisely—and never, ever commit it.

You need to run a production build on your local machine:

.env.local.production -

The difference is purely syntactical. Most modern frameworks prefer the former ( env.production.local ), but legacy systems or custom CI/CD pipelines might recognize the latter. If you have .env and .env.production , why introduce a third file? The answer lies in sensitive, environment-specific configuration .

Audit your environment loading logic today. Does your framework recognize .env.local.production ? If not, you may be chasing bugs that don't exist. If yes, use it wisely—and never, ever commit it. .env.local.production

You need to run a production build on your local machine: The difference is purely syntactical