> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# LSET

> Set element at index.

Use `LSET` to overwrite the element at a given position in a list.

Indexes are zero-based from the head and negative indexes count from the tail. The command returns an error when the key does not exist or the index is out of range, since it never grows the list; use [`LPUSH`](/docs/redis/commands/list/lpush) or [`RPUSH`](/docs/redis/commands/list/rpush) to add elements. Locate the position first with [`LPOS`](/docs/redis/commands/list/lpos) when you know the value but not the index.

## Syntax

```redis theme={"system"}
LSET <key> <index> <element>
```

## Arguments

| Argument    | Required | Repeatable | Description                                           |
| ----------- | -------- | ---------- | ----------------------------------------------------- |
| `<key>`     | Yes      | No         | Redis key targeted by the command.                    |
| `<index>`   | Yes      | No         | Zero-based index; negative values count from the end. |
| `<element>` | Yes      | No         | Element to store at the index.                        |

## Response

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.

| Protocol | Reply              |
| -------- | ------------------ |
| RESP2    | Simple string `OK` |
| RESP3    | Simple string `OK` |

<Note>
  Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.
</Note>

## Examples

TCP examples use the TLS `REDIS_URL` from the Upstash console. REST examples use `UPSTASH_REDIS_REST_URL` and `UPSTASH_REDIS_REST_TOKEN`.

<AccordionGroup>
  <Accordion title="Redis CLI" icon="terminal">
    ```bash theme={"system"}
    LSET my-key 0 element
    ```
  </Accordion>

  <Accordion title="@upstash/redis" icon="node-js" iconType="brands">
    ```ts theme={"system"}
    import { Redis } from "@upstash/redis";

    const redis = Redis.fromEnv();

    await redis.lpush("key", "a", "b", "c");
    await redis.lset("key", 1, "d");

    // list is now ["a", "d", "c"]
    ```
  </Accordion>

  <Accordion title="upstash_redis" icon="python" iconType="brands">
    ```python theme={"system"}
    from upstash_redis import Redis

    redis = Redis.from_env()
    result = redis.lset("my-key", 0, "element")
    print(result)
    ```
  </Accordion>

  <Accordion title="ioredis" icon="node-js" iconType="brands">
    ```ts theme={"system"}
    import Redis from "ioredis";

    const redis = new Redis(process.env.REDIS_URL!);
    const result = await redis.lset("my-key", "0", "element");
    console.log(result);
    ```
  </Accordion>

  <Accordion title="node-redis" icon="node-js" iconType="brands">
    ```ts theme={"system"}
    import { createClient } from "redis";

    const client = await createClient({ url: process.env.REDIS_URL })
      .on("error", console.error)
      .connect();
    const result = await client.lSet("my-key", 0, "element");
    console.log(result);
    ```
  </Accordion>

  <Accordion title="redis-py" icon="python" iconType="brands">
    ```python theme={"system"}
    import os
    import redis

    client = redis.from_url(os.environ["REDIS_URL"])
    result = client.lset("my-key", 0, "element")
    print(result)
    ```
  </Accordion>

  <Accordion title="go-redis" icon="golang" iconType="brands">
    ```go theme={"system"}
    package main

    import (
        "context"
        "fmt"
        "os"

        "github.com/redis/go-redis/v9"
    )

    func main() {
        opts, err := redis.ParseURL(os.Getenv("REDIS_URL"))
        if err != nil {
            panic(err)
        }
        client := redis.NewClient(opts)
        result, err := client.LSet(context.Background(), "my-key", 0, "element").Result()
        if err != nil {
            panic(err)
        }
        fmt.Println(result)
    }
    ```
  </Accordion>

  <Accordion title="jedis" icon="java" iconType="brands">
    ```java theme={"system"}
    import java.net.URI;

    import redis.clients.jedis.Jedis;

    try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {
      Object result = jedis.lset("my-key", 0, "element");
      System.out.println(result);
    }
    ```
  </Accordion>

  <Accordion title="redis-rs" icon="rust" iconType="brands">
    ```rust theme={"system"}
    use redis::TypedCommands;

    fn main() -> redis::RedisResult<()> {
        let url = std::env::var("REDIS_URL").expect("REDIS_URL is not set");
        let client = redis::Client::open(url)?;
        let mut connection = client.get_connection()?;

        let result = connection.lset("my-key", 0, "element")?;
        println!("{result:?}");
        Ok(())
    }
    ```
  </Accordion>
</AccordionGroup>


## Related topics

- [LSET](/docs/redis/sdks/py/commands/list/lset.md)
- [LPOS](/docs/redis/commands/list/lpos.md)
- [Overview](/docs/redis/sdks/py/commands/overview.md)