Using lconvert

The lconvert command line tool filters and converts translation data files.

It supports the following file formats:

pot - GNU Gettext localization template files
qph - Qt Linguist Phrase Book
ts - Qt translation sources
po - GNU Gettext localization files
qm - Compiled Qt translations
xlf - XLIFF localization files

lconvert syntax

lconvert [options] <infile> [<infile>...]

Where:

options means one or several lconvert options.
infile is an input file. You can specify multiple input files.

If you specify multiple input files, they are merged with translations from later files taking precedence.

To view the latest lconvert help, enter:

lconvert -help

lconvert options

Option	Action
`-h` `-help`	Display up-to-date help information and exit.
`-i <infile>` `-input-file <infile>`	Specify an input file. Use this option if `<infile>` starts with a dash. Use this option several times to merge inputs. May be `-` (standard input) for use in a pipe.
`-o <outfile>` `-output-file <outfile>`	Specify an output file. Default is `-` (standard output).
`-if <informat>` `-input-format <format>`	Specify input format for subsequent input files. The format is auto-detected from the file name and defaults to `ts`.
`-of <outformat>` `-output-format <outformat>`	Specify output format. See `-if`.
`-drop-tags <regexp>`	Drop named extra tags when writing `TS` or `XLIFF` files. You can specify this option repeatedly.
`-drop-translations`	Drop existing translations and reset the status to `unfinished`. That implies `--no-obsolete`.
`-source-language <language>[_<region>]`	Specify/override the language of the source strings. Defaults to POSIX if not specified and the file does not name it yet.
`-target-language <language>[_<region>]`	Specify or override the language of the translation. By default, the target language is read from the file content or guessed from the file name.
`-no-obsolete`	Drop obsolete messages.
`-no-finished`	Drop finished messages.
`-no-untranslated`	Drop untranslated messages.
`-sort-contexts`	Sort contexts in the output `TS` file alphabetically.
`-sort-messages`	Sort messages in a context alphabetically in `TS` files.
`-locations {absolute\|relative\|none}`	Override how source code references are saved in `TS` files. Default is `absolute`.
`-no-ui-lines`	Drop line numbers from references to `UI` files.
`-pluralonly`	Drop non-plural form messages.
`-verbose`	Explain what is being done.

Examples

Convert TS file to XLIFF

To convert a single TS file to XLIFF, run the following command in the terminal:

lconvert -o myapp_de.xlf myapp_de.ts

Merge multiple QM files

The following command merges multiple QM files into full_de.qm:

lconvert -o full_de.qm qtbase_de.qm myapp_de.qm mylib_de.qm

Using lconvert with CMake

To call lconvert when configuring or building your CMake project, load the Qt6LinguistTools package and use $<TARGET_FILE_NAME:Qt6::lconvert> for locating the lconvert executable.

The following example adds a custom target xlf_de that converts a single TS file to XLIFF.

find_package(Qt6 REQUIRED COMPONENTS LinguistTools)

add_custom_command(
    OUTPUT myapp_de.xlf
    COMMAND $<TARGET_FILE:Qt6::lconvert> -o myapp_de.xlf myapp_de.ts
    DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/myapp_de.ts"
    VERBATIM
)

add_custom_target(xlf_de
    DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/myapp_de.xlf"
)

Using lrelease Translators

© 2025 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.