---
title: "len · RUAL Documentation"
description: "get the length of a list"
canonical: https://docs.rual.nl/block-types/redis/redis_list_len
language: en
---

# len

This block is part of the [`redis`](https://docs.rual.nl/block-types/redis) group and was last modified in core [`v13.0.7`](https://docs.rual.nl/core-versions/130007).

### Redis Key Selection Required

This block relies on a Redis key to perform its redis releated actions. You must manually select the Redis key you want to use in the flow in the blueprint using the Redis key selector modal. To access the modal, click the white button on the block.

get the length of a list

- flow `flow`

- length `number`

- success `condition`

- error `value`

- key `v13.0.7` `value`

| `redis llen` |
| --- |
| `llen` |

A typical wiring for [len](https://docs.rual.nl/block-types/redis/redis_list_len): a [function trigger](https://docs.rual.nl/block-types/globals/trigger_custom_function) starts the flow; [value](https://docs.rual.nl/block-types/value/value_default) feeds the `list` pin; the `flow` out pin feeds [debug](https://docs.rual.nl/block-types/state%20ui/state_debug).

![Studio canvas example for the len block: typical wiring for len.](https://docs.rual.nl/canvas-examples/redis_list_len.png)

### Version history

Introduced in [`v13.0.7`](https://docs.rual.nl/core-versions/130007).

### Service documentation