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.

Splunk SPL users

In Splunk SPL, you use the lower function. APL’s tolower provides the same functionality.

Splunk example

| eval lowercase=lower(field)

ANSI SQL users

In ANSI SQL, you use LOWER for lowercase conversion. APL’s tolower provides the same functionality.

SQL example

SELECT LOWER(field) AS lowercase FROM logs;

Usage

Syntax

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

Log analysis

Normalize HTTP methods for case-insensitive aggregation and analysis.

Query

['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

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.

List of related functions

• toupper: Converts strings to uppercase. Use this for the opposite transformation.
• totitle: Converts strings to title case. Use this for capitalized word formatting.
• strcmp: Compares strings. Use tolower before strcmp for case-insensitive comparisons.
• replace_string: Replaces strings. Use tolower to normalize before replacements.