---
url: https://listr2.kilic.dev/renderer/fallback-condition.md
---

# {{ $frontmatter.title }}

There are times other than `non-TTY` environments when you want to fallback to a fallback/silent renderer than the selected renderer.

A function that returns a boolean , or directly a boolean can be passed to *Listr* for automatically stepping down to the `fallbackRenderer` or directly to *SilentRenderer* when the condition is met.

## Behavior

### TTY or non-TTY Environment

`fallbackRenderer` will be automatically used whenever you are in a `non-TTY` environment.

* You can force to use TTY environment via *Listr* option `forceTTY` or set the environment variable `LISTR_FORCE_TTY=1`.

### Coloring

Node's built-in [`styleText`](https://nodejs.org/api/util.html#utilstyletextformat-text-options) from `node:util` is used as the underlying coloring mechanism. Colors are disabled automatically whenever it is detected as not supported.

* You can set the environment variable `FORCE_COLOR=1` to force colors.
* You can set the environment variable `NO_COLOR=1` to disable colors completely even though your environment supports it. This is very useful for tests.

### Unicode

Unicode characters like icons are not used whenever it is detected that your output does not support them.

* You can use the `forceUnicode` option on *Listr* or set the environment variable `LISTR_FORCE_UNICODE=1` to force the usage of the Unicode characters.

::: warning

These checks are primal at best but do not forget that in many cases, your terminal might support any of these UI properties, but the application in between might abstract access to them therefore it can be detected otherwise.

:::

## Usage

::: info Example

You can find the related examples [here](https://github.com/listr2/listr2/tree/master/examples/renderer-fallback-condition.example.ts).

:::

### Renderer Fallback

You can use the `fallbackRendererCondition` condition on *Listr* to determine changing your renderer to the fallback renderer.

<<< @../../examples/docs/renderer/fallback-condition/renderer-fallback.ts{15}

### Silent Renderer Fallback

You can use the `silentRendererCondition` condition on *Listr* to determine changing your renderer to *SilentRenderer*.

<<< @../../examples/docs/renderer/fallback-condition/renderer-silent.ts{15}