---
title: "Deprecation: #78670 - Deprecated CharsetConverter methods"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:deprecation-78670"
source: "Changelog/8.5/Deprecation-78670-DeprecatedCharsetConverterMethods.rst"
modified: "2026-09-15T10:46:36+00:00"
---

# Deprecation: #78670 - Deprecated CharsetConverter methods

See [forge#78670](https://forge.typo3.org/issues/78670)

## Description

The `symfony/polyfill-mbstring` package provides us with `mb_string` functionality in all installations.
Therefore some methods of `CharsetConverter` have been marked as deprecated, since the equivalent `mb_string` functions can be used directly:

-   `strlen()`: use `mb_strlen()` directly
-   `substr()`: use `mb_substr()` directly
-   `strtrunc()`: use `mb_strcut()` directly
-   `convCapitalize()`: use `mb_convert_case()` directly
-   `conv_case()`: use `mb_strtolower()` or `mb_strtoupper()` directly
-   `utf8_substr()`: use `mb_substr()` directly
-   `utf8_strlen()`: use `mb_strlen()` directly
-   `utf8_strtrunc()`: use `mb_strcut()` directly
-   `utf8_strpos()`: use `mb_strpos()` directly
-   `utf8_strrpos()`: use `mb_strrpos()` directly
-   `utf8_byte2char_pos()`: no replacement
-   `euc_strtrunc()`: use `mb_strcut()` directly
-   `euc_substr()`: use `mb_substr()` directly
-   `euc_strlen()`: use `mb_strlen()` directly
-   `euc_char2byte_pos()`: no replacement
-   `$fourByteSets`: no replacement

## Impact

Calling the deprecated `CharsetConverter` methods will trigger a deprecation log entry.

## Affected Installations

Any installation using third party extensions leveraging the mentioned `CharsetConverter` functionality.

## Migration

Use the equivalent mb_string methods directly as denoted above.