diff --git a/tools/format.sh b/tools/format.sh
index 20fcda29..ec580895 100755
--- a/tools/format.sh
+++ b/tools/format.sh
@@ -18,37 +18,69 @@ if [[ ! -e tools/format.sh ]]; then
   echo "This tool must be run from the topmost OpenCensus directory." >&2
   exit 1
 fi
+
 set -e
-# Correct common miscapitalizations.
+
+usage()
+{
+    echo "usage: format.sh [--disable-sed-check] [--disable-tools-check]"
+}
+
+sed_check=y
+tools_check=y
+
+while [[ "$1" != "" ]]; do
+    case $1 in
+        --disable-sed-check )   sed_check=n
+                                ;;
+        --disable-tools-check ) tools_check=n
+                                ;;
+        -h | --help )           usage
+                                exit
+                                ;;
+        * )                     usage
+                                exit 1
+    esac
+    shift
+done
+
 FIND="find . -name .git -prune -o -name .build -prune -o"
-sed -i 's/Open[c]ensus/OpenCensus/g' $($FIND -type f -print)
-sed -i 's/Stack[D]river/Stackdriver/g' $($FIND -type f -print)
-# No CRLF line endings.
-sed -i 's/\r$//' $($FIND -type f -print)
-# No trailing spaces.
-sed -i 's/ \+$//' $($FIND -type f -print)
-# For easier debugging: print the version because it affects the formatting.
-CMD=clang-format
-$CMD -version
-$CMD -i -style=Google \
-  $($FIND -name '*.cc' -print -o -name '*.h' -print)
-if which buildifier >/dev/null; then
-  echo "Running buildifier."
-  buildifier $($FIND -name WORKSPACE -print -o -name BUILD -print -o \
-    -name '*.bzl' -print)
-else
-  echo "Can't find buildifier. It can be installed with:"
-  echo "  go get github.com/bazelbuild/buildtools/buildifier"
+
+if [[ "$sed_check" == "y" ]]; then
+  # Correct common miscapitalizations.
+  sed -i 's/Open[c]ensus/OpenCensus/g' $($FIND -type f -print)
+  sed -i 's/Stack[D]river/Stackdriver/g' $($FIND -type f -print)
+  # No CRLF line endings.
+  sed -i 's/\r$//' $($FIND -type f -print)
+  # No trailing spaces.
+  sed -i 's/ \+$//' $($FIND -type f -print)
 fi
-if which cmake-format >/dev/null; then
-  echo "Running cmake-format $(cmake-format --version 2>&1)."
-  cmake-format -i $($FIND -name FetchContent.cmake -prune -o \
-    -name '*CMakeLists.txt' -print -o \
-    -name '*.cmake' -print)
-else
-  echo "Can't find cmake-format. It can be installed with:"
-  echo "  pip install --user cmake_format"
+
+if [[ "$tools_check" == "y" ]]; then
+  # For easier debugging: print the version because it affects the formatting.
+  CMD=clang-format
+  $CMD -version
+  $CMD -i -style=Google \
+    $($FIND -name '*.cc' -print -o -name '*.h' -print)
+  if which buildifier >/dev/null; then
+    echo "Running buildifier."
+    buildifier $($FIND -name WORKSPACE -print -o -name BUILD -print -o \
+      -name '*.bzl' -print)
+  else
+    echo "Can't find buildifier. It can be installed with:"
+    echo "  go get github.com/bazelbuild/buildtools/buildifier"
+  fi
+  if which cmake-format >/dev/null; then
+    echo "Running cmake-format $(cmake-format --version 2>&1)."
+    cmake-format -i $($FIND -name FetchContent.cmake -prune -o \
+      -name '*CMakeLists.txt' -print -o \
+      -name '*.cmake' -print)
+  else
+    echo "Can't find cmake-format. It can be installed with:"
+    echo "  pip install --user cmake_format"
+  fi
 fi
+
 CHANGED="$(git ls-files --modified)"
 if [[ ! -z "$CHANGED" ]]; then
   echo "The following files have changes:"
@@ -57,3 +89,8 @@ if [[ ! -z "$CHANGED" ]]; then
 else
   echo "No changes."
 fi
+
+if [[ "$sed_check" != "y" || "$tools_check" != "y" ]]; then
+  echo "All checks must run to succeed."
+  exit 1
+fi