There are instructions for other platforms here in the Thorium Docs directory.
Chromium requires Visual Studio 2022 (>=17.0.0) to build. Visual Studio can also be used to debug Chromium. The clang-cl compiler is used, but Visual Studio's header files, libraries, and some tools are required. Visual Studio Community Edition will work. You must install the "Desktop development with C++" component and the "MFC/ATL support" sub-components. This can be done from the command line by passing these arguments to the Visual Studio installer (see below for ARM64 instructions):
VisualStudioSetup.exe --add Microsoft.VisualStudio.Workload.NativeDesktop --add Microsoft.VisualStudio.Component.VC.ATLMFC --includeRecommended
If you want to build for Windows on ARM64 then some extra arguments are needed. The full set for that case is:
VisualStudioSetup.exe --add Microsoft.VisualStudio.Workload.NativeDesktop --add Microsoft.VisualStudio.Component.VC.ATLMFC --add Microsoft.VisualStudio.Component.VC.Tools.ARM64 --add Microsoft.VisualStudio.Component.VC.MFC.ARM64 --includeRecommended
The 10.1.22621.2428 SDK Debugging Tools must also be installed. This version of the Debugging tools is needed in order to support reading the large-page PDBs that Chrome uses to allow greater-than 4 GiB PDBs. This can be installed after the matching Windows SDK version is installed, from: Control Panel -> Programs and Features -> Windows Software Development Kit [version] -> Change -> Debugging Tools for Windows. Or, you can download the standalone SDK installer and use it to install the Debugging Tools. If building on ARM64 Windows then you will need to manually copy the Debuggers\x64 directory from another machine because it does not get installed on ARM64 and is needed, whether you are building Chromium for x64 or ARM64 on ARM64.
depot_tools
Download the depot_tools bundle and extract it to C:\src\depot_tools.
Warning: DO NOT use drag-n-drop or copy-n-paste extract from Explorer, this will not extract the hidden “.git” folder which is necessary for depot_tools to autoupdate itself. You can use “Extract all…” from the context menu, or 7-Zip though.
Add depot_tools to the start of your PATH (must be ahead of any installs of Python). Note that environment variable names are case insensitive.
Assuming you unzipped the bundle to C:\src\depot_tools, open:
Control Panel → System and Security → System → Advanced system settings
If you have Administrator access, Modify the PATH system variable and put C:\src\depot_tools at the front, by clicking "Move Up". (Or at least in front of any directory that might already
have a copy of Python or Git).
If you don't have Administrator access, you can add a user-level PATH environment variable by opening:
Control Panel → System and Security → System → Search for "Edit environment variables for your account"
Add C:\src\depot_tools at the front. Note: If your system PATH has a Python in it, you will be out of luck.
Also, add a DEPOT_TOOLS_WIN_TOOLCHAIN environment variable in the same way, and set it to 0. This tells depot_tools to use your locally installed version of Visual Studio
(by default, depot_tools will try to use a google-internal version).
You should also set the variable vs2022_install to your installation path of Visual Studio 22, like vs2022_install =
C:\Program Files\Microsoft Visual Studio\2022\Community
Once all of this is done, we will download some infra archives using gclient.
From a cmd.exe shell, run:
gclient
On first run, gclient will install all the Windows-specific bits needed to work with the code, including msysgit and Python.
After running gclient open a command prompt and type where python and confirm that the depot_tools python.bat comes ahead of any copies of python.exe. Failing to
ensure this can lead to overbuilding when using gn - see crbug.com/611087.
App Execution Aliases in Windows 10/11 can conflict with other installations of python on the system so disable these for 'python.exe' and 'python3.exe' by opening 'App execution aliases' section of Control Panel and unticking the boxes next to both of these that point to 'App Installer'.
First, configure Git (you may want to backup your current .gitconfig file if it exists):
git config --global user.name "My Name" git config --global user.email "my-name@chromium.org" git config --global core.autocrlf false git config --global core.filemode false git config --global branch.autosetuprebase always git config --global core.longpaths true
Create a chromium directory in C:\src for the checkout and change to it.
cd / && cd src && mkdir chromium && cd chromium
Run the fetch tool from depot_tools to check out the code and its dependencies.
fetch chromium
If you don't want the full repo history, you can save a lot of time by adding the --no-history flag to fetch.
Expect the command to take 30 minutes on even a fast connection, and many hours on slower ones.
When fetch completes, it will have created a hidden .gclient file and a directory called src in the working directory. The remaining
instructions assume you have switched to this directory (i.e. C:\src\chromium\src):
cd src
Optional: You can also build with API keys if you want your build to talk to some Google services like Google Sync, Translate, and GeoLocation. Thorium has its own keys in a private repository, if you are a builder or would like access to them, contact me. Otherwise, for personal or development builds, you can create your own keys and add yourself to google-browser-signin-testaccounts to enable Sync.
Using Git: It should be placed in $HOME, i.e. C:\Users$USERNAME.
git clone --recursive https://github.com/Alex313031/thorium.git
To use the build scripts, we need bash on Windows. It is recommended to use Git Bash from Git for Windows. All the following script instructions assume that Chromium is in C:\src\chromium\src and that you have changed to the thorium repo in bash.
First, we need to make sure we have all the tags/branches and are on Tip of Tree. For this, run (from within the Thorium repo):
./trunk.sh
Secondly, we need to check out the revision that Chromium is currently using. For this, run:
./version.sh
At the end it will download the PGO profiles for Chromium for all platforms. The file for Windows will be downloaded to
C:\src\chromium\src\chrome\build\pgo_profiles*.profdata with the actual file name looking something like 'chrome-win64-6167-1706032279-97e63d82a0938b7701d8cdf028299c39d523a3c6.profdata', which should
be added to the end of args.gn as per below. Take note of this, as we will be using it in the args.gn below.
Lastly, we need to copy the Thorium source files over the Chromium tree. For this, run:
./setup.sh
This will copy all the files and patches to the needed locations.
./setup.sh --avx2. To build SSE3, use ./setup.sh --sse3. Use ./setup.sh --help to see all
options/platforms.
Chromium & Thorium use Ninja as its main build tool along with a tool called GN to generate
.ninja files.
NOTE: Instructions from here on out assume you are back in cmd.exe (not Bash), and have changed to the C:\src\chromium\src directory.
Create the build output directory by running:
gn args out\thorium
This will open up notepad.exe, and this is where we will specify build arguments ("args") which direct Ninja on how to lay out the build directory tree. We will be copy/pasting the contents of the
win_args.gn file (from C:\src\Thorium\win_args.gn) into notepad. Notice the three lines at the top, related to API Keys. It is fine
to leave them blank, or add the ones you have made.
At the bottom, though, notice the line that says pgo_data_path = "". This is where we will put the full path to the PGO profile data file we downloaded earlier.
That line should look something like:
pgo_data_path = "C:\src\chromium\src\chrome\build\pgo_profiles\chrome-win64-6167-1706032279-97e63d82a0938b7701d8cdf028299c39d523a3c6.profdata"
gn help on the command line or read the quick start guide.Build Thorium (the "chrome" target), and the other things like chromedriver and thorium_shell with Ninja using the command:
autoninja -C out\thorium thorium chromedriver thorium_shell setup mini_installer -j8
(Where -j# can be any number, and should generally be set to the number of cores on your CPU).
autoninja is a wrapper that automatically provides optimal values for the arguments passed to ninja.
You can get a list of all of the other build targets from GN by running gn ls out\thorium from the command line. To compile one, pass to Ninja the GN label with no preceding "//" (so for
//chrome/test:unit_tests use autoninja -C out\thorium chrome/test:unit_tests).
Once it is built, you can simply run the browser:
out\thorium\thorium.exe
Or install it using the mini_installer:
out\thorium\mini_installer.exe
To update an existing Chromium checkout, you should run the trunk.sh script again:
./trunk.sh
This syncs the subrepositories to the appropriate versions, deleting those that are no longer needed, and re-runs the hooks as needed.
To update an existing Thorium checkout, just download the latest .zip, or do a git pull:
git pull --recurse-submodules origin main
If you have problems building, join us in the Thorium IRC Channel at #thorium on irc.libera.chat and ask there.
If you suspect that Windows Defender is slowing your build then you can try Microsoft's Performance analyzer for Microsoft Defender Antivirus to investigate in detail.
Happy Thorium Building!