# Installing additional language packs

OCRmyPDF uses Tesseract for OCR, and relies on its language packs for all languages. On most platforms, English is installed with Tesseract by default, but not always.

Tesseract supports most languages. Languages are identified by standardized three-letter codes (called ISO 639-2 Alpha-3). Tesseract’s documentation also lists the three-letter code for your language. Some are anglicized, e.g. Spanish is `spa` rather than `esp`, while others are not, e.g. German is `deu` and French is `fra`.

Language packs (strictly speaking, Tesseract “traineddata” files) generally correspond to the language in question, but different language packs are used in certain situations. For German, the “Fraktur” language pack can assist with reading older materials in the Fraktur typeface family (`deu_frak`). Some communities have changed their script from Cyrillic to Latin; the Cyrillic version of Uzbek is available as `uzb_cyrl` and the Latin version is `uzb`.

After you have installed a language pack, you can use it with `ocrmypdf -l <language>`, for example `ocrmypdf -l spa`. For multilingual documents, you can specify all languages to be expected, e.g. `ocrmypdf -l eng+fra` for English and French. English is assumed by default unless other language(s) are specified.

For Linux users, you can often find packages that provide language packs.

## Platform install steps

### Debian and Ubuntu (apt)

    # Display a list of all Tesseract language packs
    apt-cache search tesseract-ocr

    # Install Chinese Simplified language pack
    apt-get install tesseract-ocr-chi-sim

You can then pass the `-l LANG` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested using either `-l eng+fra` (English and French) or `-l eng -l fra`.

### Fedora

    # Display a list of all Tesseract language packs
    dnf search tesseract

    # Install Chinese Simplified language pack
    dnf install tesseract-langpack-chi_sim

You can then pass the `-l LANG` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested using either `-l eng+fra` (English and French) or `-l eng -l fra`.

### Arch Linux

    # Display a list of all Tesseract language packs
    pacman -Ss tesseract-data

    # Install German language pack
    pacman -S tesseract-data-deu

You can then pass the `-l LANG` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested using either `-l eng+fra` (English and French) or `-l eng -l fra`.

### Gentoo

On Gentoo the package `app-text/tessdata_fast`, which `app-text/tesseract` depends on, handles Tesseract languages. It accepts USE flags to select what languages should be installed, these can be set in `/etc/portage/package.use`. Alternatively one can globally set the L10N use extension in `/etc/portage/make.conf`. This enables these languages for all packages (e.g. including aspell).

    # Display a list of all Tesseract language packs
    equery uses app-text/tessdata_fast

    # Add English and German language support for Tesseract only
    echo 'app-text/tessdata_fast l10n_de l10n_en' >> /etc/portage/package.use

    # Add global English and German language support (the `l10n_` from equery has to be omitted)
    echo L10N="de en" >> /etc/portage/make.conf

    # update system to reflect changed USE flags
    emerge --update --deep --newuse @world

You can then pass the `-l LANG` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested using either `-l eng+fra` (English and French) or `-l eng -l fra`.

### macOS

You can install additional language packs by installing Tesseract using Homebrew with all language packs.

### Docker

Users of the OCRmyPDF Docker image should install language packs into a derived Docker image as described in that section.

### Windows

The Tesseract installer provided by Chocolatey currently includes only English language. To install other languages, download the respective language pack (`.traineddata` file) from https://github.com/tesseract-ocr/tessdata/ and place it in `C:\\Program Files\\Tesseract-OCR\\tessdata` (or wherever Tesseract OCR is installed).

## Custom language packs

If you have fine-tuned or trained Tesseract and generated custom trained data, you can copy your `customlang.traineddata` file into your Tesseract “tessdata” folder, and then use the `-l customlang` argument to tell OCRmyPDF to pass that language on to Tesseract.