QtPDF Build Instructions

Qt PDF binaries are available from the Qt installer under "Extensions"; but here's how to build it yourself.

In case of any issues, please open a bug report for the PDF component at Qt Bug Reports.

Building from git with an existing Qt 6

This step requires an existing Qt 6 installation.

• Install html5lib: hopefully your system package manager provides a python3-html5lib package; alternatively:

$ pip3 install html5lib

• Sources for the Qt PDF module are hosted within QtWebEngine repository. Clone and initialize the git repository (currently about 7.1 GB):

(Commercial Qt customers are advised to use their own access to the source code on git. See the page Getting Commercial Qt Sources for more details)

$ git clone https://code.qt.io/qt/qtwebengine.git
$ cd qtwebengine
$ git checkout 6.12 (or whatever version)
$ git submodule update --init --recursive

• Fortunately build of QtWebEngine itself is not necessary for Qt PDF. Qt PDF uses just PDFium as a part of Chromium inside the QtWebEngine. Configure a shadow build:

$ mkdir build
$ cd build
$ <path to the "bin" folder in your Qt 6 installation>/qt-configure-module ../qtwebengine -- -DQT_FEATURE_qtwebengine_build=OFF

• Build Qt PDF

$ cmake --build . --parallel

• Install Qt PDF

$ cmake --install .

This will install Qt PDF into the Qt 6 installation you specified and used above.

Test the new build with one of the examples provided by Qt PDF. See folders examples/pdf and examples/pdfwidgets.

Building from source installed with the installer

In Qt Maintenance Tool (AKA the installer) you can choose Extensions | Qt PDF | Qt 6.xx.x | Desktop to get the already-built version, and/or Extensions | Qt WebEngine | Qt 6.xx.x | Sources to get the source code for Qt WebEngine and Qt PDF together.

• configure a shadow build

$ cd ~/Qt/6.12.0/Src/qtwebengine (or whatever version)
$ mkdir build
$ cd build
$ <path to the "bin" folder of this Qt>/qt-configure-module .. -- -DQT_FEATURE_qtwebengine_build=OFF
...
 -- Configuration summary has been written to /home/username/Qt/6.12.0/Src/qtwebengine/build/config.summary
...
-- Configuring done (14.0s)
-- Generating done (0.1s)
-- Build files have been written to: /home/username/Qt/6.12.0/Src/qtwebengine/build

$ cat config.summary
WebEngine Repository Build Options:
  Build Gn ............................... yes
  Jumbo Build ............................ yes
  Developer build ........................ no
  Build with rust ........................ no
  Use precompiled headers for 3rdparty ... no
  Build QtWebEngine Modules:
    Build QtWebEngineCore ................ no
    Build QtWebEngineWidgets ............. no
    Build QtWebEngineQuick ............... no
  Build QtPdf Modules:
    Build QtPdfWidgets ................... yes
    Build QtPdfQuick ..................... yes
  Optional system libraries:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . yes
    opus ................................. yes
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... yes
    glib ................................. yes
    zlib ................................. yes
    minizip .............................. yes
    libxml2 and libxslt .................. yes
    lcms2 ................................ yes
    png .................................. no
    tiff ................................. yes
    jpeg ................................. no
    libopenjpeg2 ......................... yes
    harfbuzz ............................. no
    freetype ............................. yes
    libpci ............................... yes
    libudev .............................. yes
    openh264 ............................. yes
Qt PDF:
  Support V8 ............................. no
  Support XFA ............................ no
  Support XFA-BMP ........................ no
  Support XFA-GIF ........................ no
  Support XFA-PNG ........................ no
  Support XFA-TIFF ....................... no
  Bitcode support ........................ no
  Use static runtime ..................... no
SBOM:
  Generate SBOM .......................... yes
  Generate SPDX v2.3 ..................... yes
  Generate SPDX v2.3 JSON ................ yes (skipped if dependencies are missing)
  Verify   SPDX v2.3 JSON ................ yes (skipped if dependencies are missing)
  Generate CycloneDX v1.6 ................ no (skipped if dependencies are missing)
  Verify   CycloneDX v1.6 ................ yes (skipped if dependencies are missing)
  SBOM Python interpreter ................ Not found
  Generate source SPDX SBOM .............. no
Note: 
Scanning for ide sources...
Please note configure can execute faster if called with:
 'qt-configure-module path/to/src -- -DQT_SHOW_EXTRA_IDE_SOURCES=OFF'
WARNING: Qt WebEngine And Qt Pdf SBOM generation will be skipped due to missing dependencies. QT_INTERNAL_SBOM_PYTHON_EXECUTABLE is missing a valid path to a python interpreter
Required Python dependencies NOT found:  spdx_tools.spdx.clitools.pyspdxtools

• build

$ cmake --build . --parallel

Building Qt and Qt PDF together

When you build Qt you can include a build of Qt PDF.

• get the qt5.git repository, submodules and dependencies as explained in Building Qt 6 from Git
• configure and build a shadow build:

$ cd ..
$ mkdir qt6-dbg
$ cd qt6-dbg
$ ../qt6/configure -developer-build -debug -no-optimize-debug -nomake examples -make tests -no-pch -submodules qtbase,qtdeclarative,qtshadertools,qtwebengine -no-feature-qtwebengine-build
$ ninja

Historical repository

The older version in the Qt Labs QtPDF repository still exists, but development now continues in the qtwebengine repository. This was prompted mainly by the upstream Chromium switch of build system from gyp to gn: it was some work to get qtwebengine building with that. Chromium (and thus Qt WebEngine) includes PDFium already; so it was easier to build Qt PDF from there than to fix the build in the other repository.