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

# tolower

> This page explains how to use the tolower function in APL.

The `tolower` function converts all characters in a string to lowercase. Use this function to normalize text for case-insensitive comparisons, standardize log data, or prepare strings for consistent analysis.

## For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

<AccordionGroup>
  <Accordion title="Splunk SPL users">
    In Splunk SPL, you use the `lower` function. APL's `tolower` provides the same functionality.

    <CodeGroup>
      ```sql Splunk example theme={null}
      | eval lowercase=lower(field)
      ```

      ```kusto APL equivalent theme={null}
      ['sample-http-logs']
      | extend lowercase = tolower(field)
      ```
    </CodeGroup>
  </Accordion>

  <Accordion title="ANSI SQL users">
    In ANSI SQL, you use `LOWER` for lowercase conversion. APL's `tolower` provides the same functionality.

    <CodeGroup>
      ```sql SQL example theme={null}
      SELECT LOWER(field) AS lowercase FROM logs;
      ```

      ```kusto APL equivalent theme={null}
      ['sample-http-logs']
      | extend lowercase = tolower(field)
      ```
    </CodeGroup>
  </Accordion>
</AccordionGroup>

## Usage

### Syntax

```kusto theme={null}
tolower(value)
```

### Parameters

| Name  | Type   | Required | Description                               |
| ----- | ------ | -------- | ----------------------------------------- |
| value | string | Yes      | The input string to convert to lowercase. |

### Returns

Returns the input string with all characters converted to lowercase.

## Use case examples

<Tabs>
  <Tab title="Log analysis">
    Normalize HTTP methods for case-insensitive aggregation and analysis.

    **Query**

    ```kusto theme={null}
    ['sample-http-logs']
    | extend normalized_method = tolower(method)
    | summarize request_count = count() by normalized_method, status
    | sort by request_count desc
    | limit 10
    ```

    [Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B%27sample-http-logs%27%5D%20%7C%20extend%20normalized_method%20%3D%20tolower\(method\)%20%7C%20summarize%20request_count%20%3D%20count\(\)%20by%20normalized_method%2C%20status%20%7C%20sort%20by%20request_count%20desc%20%7C%20limit%2010%22%7D)

    **Output**

    | normalized\_method | status | request\_count |
    | ------------------ | ------ | -------------- |
    | get                | 200    | 5432           |
    | post               | 201    | 2341           |
    | get                | 404    | 1987           |

    This query normalizes HTTP methods to lowercase, ensuring that 'GET', 'Get', and 'get' are all counted together for accurate request analysis.
  </Tab>

  <Tab title="OpenTelemetry traces">
    Standardize service names for consistent cross-service analysis.

    **Query**

    ```kusto theme={null}
    ['otel-demo-traces']
    | extend normalized_service = tolower(['service.name'])
    | summarize span_count = count(), avg_duration = avg(duration) by normalized_service
    | sort by span_count desc
    | limit 10
    ```

    [Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B%27otel-demo-traces%27%5D%20%7C%20extend%20normalized_service%20%3D%20tolower\(%5B%27service.name%27%5D\)%20%7C%20summarize%20span_count%20%3D%20count\(\)%2C%20avg_duration%20%3D%20avg\(duration\)%20by%20normalized_service%20%7C%20sort%20by%20span_count%20desc%20%7C%20limit%2010%22%7D)

    **Output**

    | normalized\_service | span\_count | avg\_duration |
    | ------------------- | ----------- | ------------- |
    | frontend            | 4532        | 125ms         |
    | checkout            | 3421        | 234ms         |
    | cart                | 2987        | 89ms          |

    This query normalizes service names to lowercase, ensuring consistent grouping regardless of naming convention variations.
  </Tab>
</Tabs>

## List of related functions

* [toupper](/apl/scalar-functions/string-functions/toupper): Converts strings to uppercase. Use this for the opposite transformation.
* [totitle](/apl/scalar-functions/string-functions/totitle): Converts strings to title case. Use this for capitalized word formatting.
* [strcmp](/apl/scalar-functions/string-functions/strcmp): Compares strings. Use tolower before strcmp for case-insensitive comparisons.
* [replace\_string](/apl/scalar-functions/string-functions/replace-string): Replaces strings. Use tolower to normalize before replacements.