diff --git a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
index a5b4150..40121ac 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
@@ -102,7 +102,9 @@
             Lists.<String>newArrayList(),
             threadsOption.threads,
             EnumSet.noneOf(Setting.class),
-            /* useForkJoinPool= */ false);
+            // TODO(ulfjack): flip both these flags for improved performance.
+            /* useForkJoinPool= */ false,
+            /* useGraphlessQuery= */ false);
 
     // 1. Parse query:
     QueryExpression expr;
diff --git a/src/main/java/com/google/devtools/build/lib/query2/QueryEnvironmentFactory.java b/src/main/java/com/google/devtools/build/lib/query2/QueryEnvironmentFactory.java
index f78fcc6..bbf95159 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/QueryEnvironmentFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/QueryEnvironmentFactory.java
@@ -27,6 +27,7 @@
 import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryFunction;
 import com.google.devtools.build.lib.query2.engine.QueryEnvironment.Setting;
 import com.google.devtools.build.lib.query2.query.BlazeQueryEnvironment;
+import com.google.devtools.build.lib.query2.query.GraphlessBlazeQueryEnvironment;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.skyframe.WalkableGraph.WalkableGraphFactory;
 import java.util.List;
@@ -54,7 +55,8 @@
       Iterable<QueryFunction> extraFunctions,
       @Nullable PathPackageLocator packagePath,
       boolean blockUniverseEvaluationErrors,
-      boolean useForkJoinPool) {
+      boolean useForkJoinPool,
+      boolean useGraphlessQuery) {
     Preconditions.checkNotNull(universeScope);
     if (canUseSkyQuery(orderedResults, universeScope, packagePath, strictScope, labelFilter)) {
       return new SkyQueryEnvironment(
@@ -68,6 +70,21 @@
           universeScope,
           packagePath,
           blockUniverseEvaluationErrors);
+    } else if (useGraphlessQuery) {
+      return new GraphlessBlazeQueryEnvironment(
+          transitivePackageLoader,
+          targetProvider,
+          cachingPackageLocator,
+          targetPatternPreloader,
+          relativeWorkingDirectory,
+          keepGoing,
+          strictScope,
+          loadingPhaseThreads,
+          labelFilter,
+          eventHandler,
+          settings,
+          extraFunctions,
+          useForkJoinPool);
     } else {
       return new BlazeQueryEnvironment(
           transitivePackageLoader,
diff --git a/src/main/java/com/google/devtools/build/lib/query2/query/output/OutputFormatter.java b/src/main/java/com/google/devtools/build/lib/query2/query/output/OutputFormatter.java
index 04deae5..80c0ae7 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/query/output/OutputFormatter.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/query/output/OutputFormatter.java
@@ -18,6 +18,7 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Function;
+import com.google.common.base.Predicates;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
@@ -118,6 +119,13 @@
     return Streams.stream(formatters).map(OutputFormatter::getName).collect(joining(", "));
   }
 
+  public static String streamingFormatterNames(Iterable<OutputFormatter> formatters) {
+    return Streams.stream(formatters)
+        .filter(Predicates.instanceOf(StreamedFormatter.class))
+        .map(OutputFormatter::getName)
+        .collect(joining(", "));
+  }
+
   /**
    * Returns the output formatter for the specified command-line options.
    */
diff --git a/src/main/java/com/google/devtools/build/lib/query2/query/output/QueryOptions.java b/src/main/java/com/google/devtools/build/lib/query2/query/output/QueryOptions.java
index f0da529..8165148 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/query/output/QueryOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/query/output/QueryOptions.java
@@ -197,6 +197,17 @@
       help = "If true, uses a ForkJoinPool instead of a PriorityBlockingQueue for Skyframe.")
   public boolean useForkJoinPool;
 
+  @Option(
+      name = "experimental_graphless_query",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.QUERY,
+      effectTags = {OptionEffectTag.BUILD_FILE_SEMANTICS, OptionEffectTag.EAGERNESS_TO_EXIT},
+      help =
+          "If true, uses a Query implementation that does not make a copy of the graph. The new"
+              + " implementation only supports --order_output=no, as well as only a subset of"
+              + " output formatters.")
+  public boolean useGraphlessQuery;
+
   /** Ugly workaround since line terminator option default has to be constant expression. */
   public String getLineTerminator() {
     if (lineTerminatorNull) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/genquery/GenQuery.java b/src/main/java/com/google/devtools/build/lib/rules/genquery/GenQuery.java
index 77fc9e8..d31fc28 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/genquery/GenQuery.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/genquery/GenQuery.java
@@ -344,7 +344,8 @@
                   /*extraFunctions=*/ ImmutableList.of(),
                   /*packagePath=*/ null,
                   /*blockUniverseEvaluationErrors=*/ false,
-                  /*useForkJoinPool=*/ false);
+                  /*useForkJoinPool=*/ false,
+                  /*useGraphlessQuery=*/ false);
       QueryExpression expr = QueryExpression.parse(query, queryEnvironment);
       formatter.verifyCompatible(queryEnvironment, expr);
       targets = QueryUtil.newOrderedAggregateAllOutputFormatterCallback(queryEnvironment);
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
index 10a775d..83a713d 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
@@ -203,6 +203,7 @@
         ImmutableList.<String>of(),
         loadingPhaseThreads,
         settings,
-        /* useForkJoinPool= */ false);
+        /* useForkJoinPool= */ false,
+        /*useGraphlessQuery=*/ false);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryEnvironmentBasedCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryEnvironmentBasedCommand.java
index 2d0f8a8..9d46140 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryEnvironmentBasedCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryEnvironmentBasedCommand.java
@@ -139,6 +139,16 @@
 
     Set<Setting> settings = queryOptions.toSettings();
     boolean streamResults = QueryOutputUtils.shouldStreamResults(queryOptions, formatter);
+    if (queryOptions.useGraphlessQuery && !streamResults) {
+      env.getReporter()
+          .handle(
+              Event.error(
+                  String.format(
+                      "--experimental_graphless_query requires --order_output=no and an --output"
+                          + " option that supports streaming; valid values are: %s",
+                      OutputFormatter.streamingFormatterNames(formatters))));
+      return BlazeCommandResult.exitCode(ExitCode.COMMAND_LINE_ERROR);
+    }
 
     try (QueryRuntimeHelper queryRuntimeHelper =
         env.getRuntime().getQueryRuntimeHelperFactory().create(env)) {
@@ -151,7 +161,8 @@
               queryOptions.universeScope,
               options.getOptions(LoadingPhaseThreadsOption.class).threads,
               settings,
-              queryOptions.useForkJoinPool)) {
+              queryOptions.useForkJoinPool,
+              queryOptions.useGraphlessQuery)) {
         result =
             doQuery(
                 query, env, queryOptions, streamResults, formatter, queryEnv, queryRuntimeHelper);
@@ -200,7 +211,8 @@
       List<String> universeScope,
       int loadingPhaseThreads,
       Set<Setting> settings,
-      boolean useForkJoinPool) {
+      boolean useForkJoinPool,
+      boolean useGraphlessQuery) {
 
     WalkableGraph walkableGraph =
         SkyframeExecutorWrappingWalkableGraph.of(env.getSkyframeExecutor());
@@ -235,6 +247,7 @@
             env.getRuntime().getQueryFunctions(),
             env.getPackageManager().getPackagePath(),
             /*blockUniverseEvaluationErrors=*/ false,
-            useForkJoinPool);
+            useForkJoinPool,
+            useGraphlessQuery);
   }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/query2/engine/GraphlessQueryTest.java b/src/test/java/com/google/devtools/build/lib/query2/engine/GraphlessQueryTest.java
index d4ee02e..b60ebfd 100644
--- a/src/test/java/com/google/devtools/build/lib/query2/engine/GraphlessQueryTest.java
+++ b/src/test/java/com/google/devtools/build/lib/query2/engine/GraphlessQueryTest.java
@@ -113,7 +113,8 @@
               Iterable<QueryFunction> extraFunctions,
               @Nullable PathPackageLocator packagePath,
               boolean blockUniverseEvaluationErrors,
-              boolean useForkJoinPool) {
+              boolean useForkJoinPool,
+              boolean useGraphlessQuery) {
             return new GraphlessBlazeQueryEnvironment(
                 transitivePackageLoader,
                 targetProvider,
diff --git a/src/test/java/com/google/devtools/build/lib/query2/engine/SkyframeQueryHelper.java b/src/test/java/com/google/devtools/build/lib/query2/engine/SkyframeQueryHelper.java
index 16db39b..b825fbf 100644
--- a/src/test/java/com/google/devtools/build/lib/query2/engine/SkyframeQueryHelper.java
+++ b/src/test/java/com/google/devtools/build/lib/query2/engine/SkyframeQueryHelper.java
@@ -200,7 +200,8 @@
         getExtraQueryFunctions(),
         pkgManager.getPackagePath(),
         blockUniverseEvaluationErrors,
-        /*useForkJoinPool=*/ false);
+        /*useForkJoinPool=*/ false,
+        /*useGraphlessQuery=*/ false);
   }
 
   protected abstract Iterable<QueryFunction> getExtraQueryFunctions();