> ## 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.

# isimei

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

Use the `isimei` function to check whether a given string is a valid International Mobile Equipment Identity (IMEI) number. IMEIs are unique identifiers assigned to mobile devices, often used in mobile network logs, telecom datasets, and security investigations to distinguish devices.

You can use this function to:

* Validate whether a string field contains a proper IMEI format.
* Filter out malformed or suspicious entries in datasets containing device identifiers.
* Improve data quality when analyzing logs with user agent or device metadata.

`isimei` is especially useful when dealing with telemetry or audit data where IMEI values are passed through APIs, headers, or form fields, and you want to ensure they conform to a valid format.

## 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">
    Splunk SPL doesn’t include a built-in function for validating IMEI numbers. To replicate this logic, you typically use regular expressions and custom validation logic in `eval` or `where` clauses.

    In APL, you can use `isimei` directly to check if a string is a valid IMEI number, simplifying your query.

    <CodeGroup>
      ```sql Splunk example theme={null}
      | eval is_imei=if(match(imei_field, "^[0-9]{15}$"), "true", "false") | where is_imei="true"
      ```

      ```kusto APL equivalent theme={null}
      | where isimei(imei_field)
      ```
    </CodeGroup>
  </Accordion>

  <Accordion title="ANSI SQL users">
    ANSI SQL doesn’t include native IMEI validation functions. You typically rely on pattern matching with `LIKE` or regular expressions, if supported.

    APL provides a dedicated `isimei` function to simplify this task.

    <CodeGroup>
      ```sql SQL example theme={null}
      SELECT *
      FROM device_logs
      WHERE imei_field LIKE '[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
      ```

      ```kusto APL equivalent theme={null}
      ['sample-http-logs']
      | where isimei(id)
      ```
    </CodeGroup>
  </Accordion>
</AccordionGroup>

## Usage

### Syntax

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

### Parameters

| Name  | Type   | Description                                  |
| ----- | ------ | -------------------------------------------- |
| value | string | The value to test for valid IMEI formatting. |

### Returns

A `bool` value:

* `true` if the input string is a valid IMEI number.
* `false` otherwise.

A valid IMEI is a 15-digit string that passes the [Luhn algorithm](https://en.wikipedia.org/wiki/Luhn_algorithm) checksum.

## Example

**Query**

```kusto theme={null}
['sample-http-logs']
| extend has_imei = isimei('356938035643809')
| project _time, has_imei
```

[Run in Playground](https://play.axiom.co/axiom-play-qf1k/query?initForm=%7B%22apl%22%3A%22%5B'sample-http-logs'%5D%20%7C%20extend%20has_imei%20%3D%20isimei\('356938035643809'\)%20%7C%20project%20_time%2C%20has_imei%22%7D)

**Output**

| \_time               | has\_imei |
| -------------------- | --------- |
| 2025-07-10T08:21:00Z | true      |

## List of related functions

* [isreal](/apl/scalar-functions/type-functions/ismap): Checks whether a value is a real number.
* [iscc](/apl/scalar-functions/type-functions/iscc): Checks whether a value is a valid credit card (CC) number.
* [isstring](/apl/scalar-functions/type-functions/isstring): Checks whether a value is a string. Use this for scalar string validation.
* [isutf8](/apl/scalar-functions/type-functions/isutf8): Checks whether a value is a valid UTF-8 encoded sequence.