diff --git a/cmd/registry/cmd/compute/vocabulary/vocabulary.go b/cmd/registry/cmd/compute/vocabulary/vocabulary.go
index da6a48db0..e962d4ad7 100644
--- a/cmd/registry/cmd/compute/vocabulary/vocabulary.go
+++ b/cmd/registry/cmd/compute/vocabulary/vocabulary.go
@@ -18,6 +18,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/apigee/registry/cmd/registry/compress"
 	"github.com/apigee/registry/cmd/registry/tasks"
 	"github.com/apigee/registry/pkg/connection"
 	"github.com/apigee/registry/pkg/log"
@@ -27,6 +28,7 @@ import (
 	"github.com/apigee/registry/rpc"
 	"github.com/google/gnostic/metrics/vocabulary"
 	"github.com/spf13/cobra"
+	"google.golang.org/grpc/metadata"
 	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
 
@@ -117,12 +119,19 @@ func (task *computeVocabularyTask) String() string {
 }
 
 func (task *computeVocabularyTask) Run(ctx context.Context) error {
+	ctx = metadata.AppendToOutgoingContext(ctx, "accept-encoding", "gzip")
 	contents, err := task.client.GetApiSpecContents(ctx, &rpc.GetApiSpecContentsRequest{
 		Name: task.specName,
 	})
 	if err != nil {
 		return err
 	}
+	if mime.IsGZipCompressed(contents.ContentType) {
+		contents.Data, err = compress.GUnzippedBytes(contents.Data)
+		if err != nil {
+			return err
+		}
+	}
 
 	log.Debugf(ctx, "Computing %s/artifacts/vocabulary", task.specName)
 	var vocab *metrics.Vocabulary
@@ -155,7 +164,7 @@ func (task *computeVocabularyTask) Run(ctx context.Context) error {
 			return nil
 		}
 	} else {
-		return fmt.Errorf("we don't know how to summarize %s", task.specName)
+		return fmt.Errorf("we don't know how to compute the vocabulary of %s", task.specName)
 	}
 
 	if task.dryRun {
diff --git a/pkg/visitor/fetch_test.go b/pkg/visitor/fetch_test.go
index c036ba687..2930f2bff 100644
--- a/pkg/visitor/fetch_test.go
+++ b/pkg/visitor/fetch_test.go
@@ -15,9 +15,11 @@
 package visitor
 
 import (
+	"bytes"
 	"context"
 	"testing"
 
+	"github.com/apigee/registry/cmd/registry/compress"
 	"github.com/apigee/registry/pkg/connection/grpctest"
 	"github.com/apigee/registry/pkg/names"
 	"github.com/apigee/registry/rpc"
@@ -29,6 +31,10 @@ func TestFetch(t *testing.T) {
 	parent := project.String() + "/locations/global"
 
 	specContents := "hello"
+	gzippedSpecContents, err := compress.GZippedBytes([]byte(specContents))
+	if err != nil {
+		t.Fatalf("Setup: Failed to compress test data: %s", err)
+	}
 	artifactContents := "hello"
 
 	ctx := context.Background()
@@ -62,8 +68,8 @@ func TestFetch(t *testing.T) {
 		ApiSpecId: "s",
 		Parent:    versionName.String(),
 		ApiSpec: &rpc.ApiSpec{
-			Contents: []byte(specContents),
-			MimeType: "text/plain",
+			Contents: gzippedSpecContents,
+			MimeType: "text/plain+gzip",
 		},
 	})
 	if err != nil {
@@ -91,7 +97,7 @@ func TestFetch(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Failed to fetch spec contents: %s", err)
 		}
-		if string(spec.Contents) != specContents {
+		if !bytes.Equal(spec.Contents, gzippedSpecContents) {
 			t.Fatalf("Fetched unexpected spec contents: wanted %q got %q", specContents, spec.Contents)
 		}
 	})
@@ -111,7 +117,7 @@ func TestFetch(t *testing.T) {
 			t.Fatalf("Failed to parse spec name: %s", err)
 		}
 		err = GetSpec(ctx, registryClient, specName, true, func(ctx context.Context, spec *rpc.ApiSpec) error {
-			if string(spec.Contents) != specContents {
+			if !bytes.Equal(spec.Contents, gzippedSpecContents) {
 				t.Fatalf("Fetched unexpected spec contents: wanted %q got %q", specContents, spec.Contents)
 			}
 			return nil
@@ -146,7 +152,7 @@ func TestFetch(t *testing.T) {
 			t.Fatalf("Failed to parse spec revision name: %s", err)
 		}
 		err = GetSpecRevision(ctx, registryClient, specRevisionName, true, func(ctx context.Context, spec *rpc.ApiSpec) error {
-			if string(spec.Contents) != specContents {
+			if !bytes.Equal(spec.Contents, gzippedSpecContents) {
 				t.Fatalf("Fetched unexpected spec contents: wanted %q got %q", specContents, spec.Contents)
 			}
 			return nil
diff --git a/pkg/visitor/list.go b/pkg/visitor/list.go
index a2a39e157..eb0907bd6 100644
--- a/pkg/visitor/list.go
+++ b/pkg/visitor/list.go
@@ -18,11 +18,14 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/apigee/registry/cmd/registry/compress"
 	"github.com/apigee/registry/gapic"
+	"github.com/apigee/registry/pkg/mime"
 	"github.com/apigee/registry/pkg/names"
 	"github.com/apigee/registry/rpc"
 	"google.golang.org/api/iterator"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
 )
 
@@ -186,6 +189,7 @@ func ListSpecs(ctx context.Context,
 		}
 
 		if getContents {
+			ctx = metadata.AppendToOutgoingContext(ctx, "accept-encoding", "gzip")
 			resp, err := client.GetApiSpecContents(ctx, &rpc.GetApiSpecContentsRequest{
 				Name: r.GetName(),
 			})
@@ -193,6 +197,12 @@ func ListSpecs(ctx context.Context,
 				return err
 			}
 			r.Contents = resp.GetData()
+			if mime.IsGZipCompressed(resp.ContentType) {
+				r.Contents, err = compress.GUnzippedBytes(r.Contents)
+				if err != nil {
+					return err
+				}
+			}
 		}
 
 		if err := handler(ctx, r); err != nil {
@@ -217,6 +227,7 @@ func ListSpecRevisions(ctx context.Context,
 		}
 
 		if getContents {
+			ctx = metadata.AppendToOutgoingContext(ctx, "accept-encoding", "gzip")
 			resp, err := client.GetApiSpecContents(ctx, &rpc.GetApiSpecContentsRequest{
 				Name: r.GetName(),
 			})
@@ -224,6 +235,12 @@ func ListSpecRevisions(ctx context.Context,
 				return err
 			}
 			r.Contents = resp.GetData()
+			if mime.IsGZipCompressed(resp.ContentType) {
+				r.Contents, err = compress.GUnzippedBytes(r.Contents)
+				if err != nil {
+					return err
+				}
+			}
 		}
 
 		if err := handler(ctx, r); err != nil {