---
title: settings
description: The following settings are provided to alter how Express will behave
---

<h3 id='app-settings'>settings</h3>

The following settings are provided to alter how Express will behave:

- `env` Environment mode, defaults to process.env.NODE_ENV or "development"
- `trust proxy` Enables reverse proxy support, disabled by default
- `jsonp callback name` Changes the default callback name of ?callback=
- `json replacer` JSON replacer callback, null by default
- `json spaces` JSON response spaces for formatting, defaults to 2 in development, 0 in production
- `case sensitive routing` Enable case sensitivity, disabled by default, treating "/Foo" and "/foo" as the same
- `strict routing` Enable strict routing, by default "/foo" and "/foo/" are treated the same by the router
- `view cache` Enables view template compilation caching, enabled in production by default
- `view engine` The default engine extension to use when omitted
- `views` The view directory path, defaulting to "process.cwd() + '/views'"
