diff --git a/build/autoconf/clang-plugin.m4 b/build/autoconf/clang-plugin.m4
index a3618189189e..08d6329bf02e 100644
--- a/build/autoconf/clang-plugin.m4
+++ b/build/autoconf/clang-plugin.m4
@@ -133,7 +133,6 @@ AC_SUBST_LIST(LLVM_LDFLAGS)
 AC_SUBST_LIST(CLANG_LDFLAGS)
 
 AC_SUBST(ENABLE_CLANG_PLUGIN)
-AC_SUBST(ENABLE_CLANG_PLUGIN_ALPHA)
 AC_SUBST(ENABLE_MOZSEARCH_PLUGIN)
 
 ])
diff --git a/build/clang-plugin/DiagnosticsMatcher.cpp b/build/clang-plugin/DiagnosticsMatcher.cpp
index 96d2f60440b7..d6841eab6a31 100644
--- a/build/clang-plugin/DiagnosticsMatcher.cpp
+++ b/build/clang-plugin/DiagnosticsMatcher.cpp
@@ -10,8 +10,5 @@ DiagnosticsMatcher::DiagnosticsMatcher(CompilerInstance &CI) {
   cls##_.registerPPCallbacks(CI);
 #include "Checks.inc"
 #include "external/ExternalChecks.inc"
-#ifdef MOZ_CLANG_PLUGIN_ALPHA
-#include "alpha/AlphaChecks.inc"
-#endif
 #undef CHECK
 }
diff --git a/build/clang-plugin/DiagnosticsMatcher.h b/build/clang-plugin/DiagnosticsMatcher.h
index 2738541f62c6..b93aa5333f5d 100644
--- a/build/clang-plugin/DiagnosticsMatcher.h
+++ b/build/clang-plugin/DiagnosticsMatcher.h
@@ -7,9 +7,6 @@
 
 #include "ChecksIncludes.inc"
 #include "external/ExternalIncludes.inc"
-#ifdef MOZ_CLANG_PLUGIN_ALPHA
-#include "alpha/AlphaIncludes.inc"
-#endif
 
 class DiagnosticsMatcher {
 public:
@@ -21,9 +18,6 @@ private:
 #define CHECK(cls, name) cls cls##_{name};
 #include "Checks.inc"
 #include "external/ExternalChecks.inc"
-#ifdef MOZ_CLANG_PLUGIN_ALPHA
-#include "alpha/AlphaChecks.inc"
-#endif
 #undef CHECK
   MatchFinder AstMatcher;
 };
diff --git a/build/clang-plugin/MozillaTidyModule.cpp b/build/clang-plugin/MozillaTidyModule.cpp
index c78d4dc87d7b..aacb3e933585 100644
--- a/build/clang-plugin/MozillaTidyModule.cpp
+++ b/build/clang-plugin/MozillaTidyModule.cpp
@@ -20,9 +20,6 @@ public:
 #define CHECK(cls, name) CheckFactories.registerCheck<cls>("mozilla-" name);
 #include "Checks.inc"
 #include "external/ExternalChecks.inc"
-#ifdef MOZ_CLANG_PLUGIN_ALPHA
-#include "alpha/AlphaChecks.inc"
-#endif
 #undef CHECK
   }
 };
diff --git a/build/clang-plugin/alpha/AlphaChecks.inc b/build/clang-plugin/alpha/AlphaChecks.inc
deleted file mode 100644
index 33abe694da24..000000000000
--- a/build/clang-plugin/alpha/AlphaChecks.inc
+++ /dev/null
@@ -1,8 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-// The list of checker classes that are compatible with clang-tidy and are considered
-// to be in alpha stage development.
-
-// CHECK(AlphaChecker, "alpha-checker")
diff --git a/build/clang-plugin/alpha/AlphaIncludes.inc b/build/clang-plugin/alpha/AlphaIncludes.inc
deleted file mode 100644
index e69de29bb2d1..000000000000
diff --git a/build/clang-plugin/alpha/sources.mozbuild b/build/clang-plugin/alpha/sources.mozbuild
deleted file mode 100644
index a49622b0df86..000000000000
--- a/build/clang-plugin/alpha/sources.mozbuild
+++ /dev/null
@@ -1,9 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-HOST_SOURCES += [
-    # 'AlphaChecker.cpp',
-]
\ No newline at end of file
diff --git a/build/clang-plugin/alpha/tests/sources.mozbuild b/build/clang-plugin/alpha/tests/sources.mozbuild
deleted file mode 100644
index feb0bbcf33b5..000000000000
--- a/build/clang-plugin/alpha/tests/sources.mozbuild
+++ /dev/null
@@ -1,9 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-SOURCES += [
-    # 'AlphaTest.cpp',
-]
\ No newline at end of file
diff --git a/build/clang-plugin/import_mozilla_checks.py b/build/clang-plugin/import_mozilla_checks.py
index cf6c3679b1ab..b556054d4138 100755
--- a/build/clang-plugin/import_mozilla_checks.py
+++ b/build/clang-plugin/import_mozilla_checks.py
@@ -34,13 +34,9 @@ def copy_dir_contents(src, dest):
                 raise Exception('Directory not copied. Error: %s' % e)
 
 
-def write_cmake(module_path, import_alpha):
+def write_cmake(module_path):
     names = ['  ' + os.path.basename(f) for f in glob.glob("%s/*.cpp" % module_path)]
     names += ['  ' + os.path.basename(f) for f in glob.glob("%s/external/*.cpp" % module_path)]
-    if import_alpha:
-        alpha_names = ['  ' + os.path.join("alpha", os.path.basename(f))
-                       for f in glob.glob("%s/alpha/*.cpp" % module_path)]
-        names += alpha_names
     with open(os.path.join(module_path, 'CMakeLists.txt'), 'w') as f:
         f.write("""set(LLVM_LINK_COMPONENTS support)
 
@@ -118,7 +114,7 @@ def generate_thread_allows(mozilla_path, module_path):
         f.write(ThreadAllows.generate_allows({files, names}))
 
 
-def do_import(mozilla_path, clang_tidy_path, import_alpha):
+def do_import(mozilla_path, clang_tidy_path):
     module = 'mozilla'
     module_path = os.path.join(clang_tidy_path, module)
     try:
@@ -130,7 +126,7 @@ def do_import(mozilla_path, clang_tidy_path, import_alpha):
     copy_dir_contents(mozilla_path, module_path)
     write_third_party_paths(mozilla_path, module_path)
     generate_thread_allows(mozilla_path, module_path)
-    write_cmake(module_path, import_alpha)
+    write_cmake(module_path)
     add_item_to_cmake_section(os.path.join(module_path, '..', 'plugin',
                                            'CMakeLists.txt'),
                               'LINK_LIBS', 'clangTidyMozillaModule')
@@ -149,11 +145,10 @@ static int LLVM_ATTRIBUTE_UNUSED MozillaModuleAnchorDestination =
 
 
 def main():
-    if len(sys.argv) < 3 or len(sys.argv) > 4:
+    if len(sys.argv) != 3:
         print("""\
-Usage: import_mozilla_checks.py <mozilla-clang-plugin-path> <clang-tidy-path> [import_alpha]
+Usage: import_mozilla_checks.py <mozilla-clang-plugin-path> <clang-tidy-path>
 Imports the Mozilla static analysis checks into a clang-tidy source tree.
-If `import_alpha` is specified then in-tree alpha checkers will be also imported.
 """)
 
         return
@@ -166,12 +161,7 @@ If `import_alpha` is specified then in-tree alpha checkers will be also imported
     if not os.path.isdir(mozilla_path):
         print("Invalid path to clang-tidy source directory")
 
-    import_alpha = False
-
-    if len(sys.argv) == 4 and sys.argv[3] == 'import_alpha':
-        import_alpha = True
-
-    do_import(mozilla_path, clang_tidy_path, import_alpha)
+    do_import(mozilla_path, clang_tidy_path)
 
 
 if __name__ == '__main__':
diff --git a/build/clang-plugin/moz.build b/build/clang-plugin/moz.build
index 5abbf93ee405..1854d989a4ce 100644
--- a/build/clang-plugin/moz.build
+++ b/build/clang-plugin/moz.build
@@ -95,10 +95,6 @@ DIRS += [
 
 include('external/sources.mozbuild')
 
-if CONFIG['ENABLE_CLANG_PLUGIN_ALPHA']:
-    HOST_DEFINES["MOZ_CLANG_PLUGIN_ALPHA"] = "1"
-    include('alpha/sources.mozbuild')
-
 # In the current moz.build world, we need to override essentially every
 # variable to limit ourselves to what we need to build the clang plugin.
 if CONFIG['HOST_OS_ARCH'] == 'WINNT':
diff --git a/build/clang-plugin/tests/moz.build b/build/clang-plugin/tests/moz.build
index 04ae2cabd3de..75a58d0e429f 100644
--- a/build/clang-plugin/tests/moz.build
+++ b/build/clang-plugin/tests/moz.build
@@ -62,10 +62,6 @@ if CONFIG['OS_ARCH'] == 'WINNT':
 
 include('../external/tests/sources.mozbuild')
 
-if CONFIG['ENABLE_CLANG_PLUGIN_ALPHA']:
-    DEFINES["MOZ_CLANG_PLUGIN_ALPHA"] = "1"
-    include('../alpha/tests/sources.mozbuild')
-
 DisableStlWrapping()
 NoVisibilityFlags()
 
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index bf225cce7bda..627596b951d2 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -2249,20 +2249,6 @@ js_option('--enable-clang-plugin', env='ENABLE_CLANG_PLUGIN',
 add_old_configure_assignment('ENABLE_CLANG_PLUGIN',
                              depends_if('--enable-clang-plugin')(lambda _: True))
 
-js_option('--enable-clang-plugin-alpha', env='ENABLE_CLANG_PLUGIN_ALPHA',
-            help='Enable static analysis with clang-plugin alpha checks.')
-
-@depends('--enable-clang-plugin', '--enable-clang-plugin-alpha')
-def check_clang_plugin_alpha(enable_clang_plugin, enable_clang_plugin_alpha):
-    if enable_clang_plugin_alpha:
-        if enable_clang_plugin:
-            return True
-        die("Cannot enable clang-plugin alpha checkers without --enable-clang-plugin.")
-    return False
-
-add_old_configure_assignment('ENABLE_CLANG_PLUGIN_ALPHA', check_clang_plugin_alpha)
-set_define('MOZ_CLANG_PLUGIN_ALPHA', check_clang_plugin_alpha)
-
 js_option('--enable-mozsearch-plugin', env='ENABLE_MOZSEARCH_PLUGIN',
           help="Enable building with the mozsearch indexer plugin")
 
diff --git a/docs/code-quality/static-analysis.rst b/docs/code-quality/static-analysis.rst
index f46016b7efe4..4c3523d9fead 100644
--- a/docs/code-quality/static-analysis.rst
+++ b/docs/code-quality/static-analysis.rst
@@ -146,8 +146,6 @@ If you want to build with the Firefox Clang plug-in
 (located in ``/build/clang-plugin`` and associated with
 ``MOZ_CLANG_PLUGIN`` and the attributes in ``/mfbt/Attributes.h``)
 just add ``--enable-clang-plugin`` to your mozconfig!
-If you want to also have our experimental checkers that will produce ``warnings`` as
-diagnostic messages also add ``--enable-clang-plugin-alpha``.
 This requires to build Firefox using Clang.
 
 Configuring the build environment