diff --git a/client/clienter.go b/client/clienter.go
index c2bb74d..924586f 100644
--- a/client/clienter.go
+++ b/client/clienter.go
@@ -8,12 +8,13 @@ import (
 
 type Clienter interface {
 	Add(ctx context.Context, dirs []string, name, baseURL string) error
+	Branches(ctx context.Context, repoDirs []string, args ...string) error
 	CheckoutRepos(ctx context.Context, repoDirs []string, args ...string) error
 	CloneRepos(ctx context.Context, dir string) ([]*Repository, error)
+	DiffRepos(ctx context.Context, repoDirs []string, args ...string) error
 	GetDirs(ctx context.Context, dir string) ([]string, error)
 	GetLogins(ctx context.Context) ([]string, error)
 	GetRepos(ctx context.Context, name string) ([]*github.Repository, error)
-	Branches(ctx context.Context, repoDirs []string, args ...string) error
 	ListTags(ctx context.Context, repoDirs []string, args ...string) error
 	PullRepos(ctx context.Context, repoDirs []string, args ...string) error
 	PushRepos(ctx context.Context, repoDirs []string, args ...string) error
diff --git a/client/repos_diff.go b/client/repos_diff.go
new file mode 100644
index 0000000..c46189d
--- /dev/null
+++ b/client/repos_diff.go
@@ -0,0 +1,45 @@
+package client
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+func (c *Client) DiffRepos(ctx context.Context, dirs []string, args ...string) error {
+	args = append([]string{"diff"}, args...)
+
+	c.scrb.BeginDescribe("Command")
+	defer c.scrb.EndDescribe()
+
+	c.scrb.Print(fmt.Sprintf("git %s", strings.Join(args, " ")))
+
+	c.scrb.BeginDescribe("directories")
+	defer c.scrb.EndDescribe()
+
+	for _, dir := range dirs {
+		out := &bytes.Buffer{}
+		errout := &bytes.Buffer{}
+
+		cmd := exec.CommandContext(ctx, "git", args...)
+		cmd.Stdout = out
+		cmd.Stderr = errout
+		cmd.Dir = dir
+
+		err := cmd.Run()
+
+		c.scrb.BeginDescribe(dir)
+		if err != nil {
+			c.scrb.Error(err)
+			c.scrb.PrintLines(errout)
+		} else {
+			c.scrb.PrintLines(out)
+		}
+
+		c.scrb.EndDescribe()
+	}
+
+	return nil
+}
diff --git a/client/testclient/client.go b/client/testclient/client.go
index 9fcf52d..78f1e75 100644
--- a/client/testclient/client.go
+++ b/client/testclient/client.go
@@ -98,3 +98,9 @@ func (c *TestClient) TagRepos(ctx context.Context, repoDirs []string, args ...st
 
 	return nil
 }
+
+func (c *TestClient) DiffRepos(ctx context.Context, repoDirs []string, args ...string) error {
+	c.CommandsCalled = append(c.CommandsCalled, "DiffRepos")
+
+	return nil
+}
diff --git a/cmd/diff.go b/cmd/diff.go
new file mode 100644
index 0000000..5223fc8
--- /dev/null
+++ b/cmd/diff.go
@@ -0,0 +1,58 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	short    bool
+	nameOnly bool
+)
+
+func init() {
+	RootCmd.AddCommand(diffCmd)
+
+	diffCmd.Flags().StringVar(&dir, "dir", ".", "directory to diff repos from")
+	diffCmd.Flags().BoolVar(&short, "shortstat", false, "show only the number of changed files, insertions, and deletions")
+	diffCmd.Flags().BoolVar(&nameOnly, "name-only", false, "show only names of changed files")
+
+	diffCmd.MarkFlagsMutuallyExclusive("shortstat", "name-only")
+}
+
+var diffCmd = &cobra.Command{
+	Use:   "diff [flags] <branch|tag> <branch|tag>",
+	Short: "Diff all repos in a directory",
+	Long: `Diff all repos in a directory. Since commit hashes would not be the same between multiple repos,
+this command really only makes sense when used with two branch names or two tags.`,
+	Args:             cobra.ExactArgs(2),
+	PersistentPreRun: setupClient,
+	RunE:             diffFunc,
+}
+
+func diffFunc(cmd *cobra.Command, args []string) error {
+	ctx := context.Background()
+
+	repoDirs, err := clt.GetDirs(ctx, dir)
+	if err != nil {
+		cmd.SilenceUsage = true
+		return fmt.Errorf("get dirs: %w", err)
+	}
+
+	switch {
+	case short:
+		args = append(args, "--shortstat")
+	case nameOnly:
+		args = append(args, "--name-only")
+	}
+
+	err = clt.DiffRepos(ctx, repoDirs, args...)
+	if err != nil {
+		cmd.SilenceUsage = true
+		return fmt.Errorf("diff repos: %w", err)
+	}
+
+	return nil
+}