By using .env.development.local , a developer can test features with their own unique database string or API key without affecting the rest of the team's shared .env.development file. Key Use Cases
: Variables here only load when the application is running in "development" mode (e.g., via npm run dev or npm start ). The Hierarchy of .env Files .env.development.local
(Highest priority for local development) .env.local .env.development .env (Lowest priority; general defaults) By using
: It is strictly for local use and should never be committed to version control (Git). By using .env.development.local