diff --git a/.gitignore b/.gitignore
index 67d08864e..7af7b3572 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 *.got.json
 *.got.svg
 e2e_report.html
+bin
diff --git a/ci/dev.sh b/ci/dev.sh
new file mode 100755
index 000000000..cbc71bf79
--- /dev/null
+++ b/ci/dev.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+set -eu
+cd -- "$(dirname "$0")/.."
+. ./ci/sub/lib.sh
+
+sh_c go build --tags=dev -o=bin/d2 .
+sh_c ./bin/d2 "$@"
diff --git a/ci/release/changelogs/next.md b/ci/release/changelogs/next.md
index 87fc8f796..2a3b66356 100644
--- a/ci/release/changelogs/next.md
+++ b/ci/release/changelogs/next.md
@@ -1,5 +1,7 @@
 #### Features 🚀
 
+- Formatting of d2 scripts is supported on the CLI with the `fmt` subcommand.
+  [#292](https://github.com/terrastruct/d2/pull/292)
 - Latex is now supported. See [docs](https://d2lang.com/tour/text) for more.
   [#229](https://github.com/terrastruct/d2/pull/229)
 - `direction` keyword is now supported to specify `up`, `down`, `right`, `left` layouts. See
diff --git a/ci/release/template/man/d2.1 b/ci/release/template/man/d2.1
index d46ca20bf..275eca9da 100644
--- a/ci/release/template/man/d2.1
+++ b/ci/release/template/man/d2.1
@@ -12,6 +12,8 @@
 .Op Ar file.svg | file.png
 .Nm d2
 .Ar layout Op Ar name
+.Nm d2
+.Ar fmt Ar file.d2
 .Sh DESCRIPTION
 .Nm
 compiles and renders
@@ -75,6 +77,10 @@ Print version information and exit.
 Lists available layout engine options with short help.
 .It Ar layout Op Ar name
 Display long help for a particular layout engine.
+.It Ar fmt Ar file.d2
+Format
+.Ar file.d2
+.Ns .
 .El
 .Sh SEE ALSO
 .Xr d2plugin-tala 1
diff --git a/ci/sub b/ci/sub
index 702b77122..a39a67857 160000
--- a/ci/sub
+++ b/ci/sub
@@ -1 +1 @@
-Subproject commit 702b771228f41e5485b5f3f593ce79f6efcb555d
+Subproject commit a39a678570a0454d6bf63f9012fb5ec107e24df5
diff --git a/fmt.go b/fmt.go
new file mode 100644
index 000000000..49fd5677b
--- /dev/null
+++ b/fmt.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+	"bytes"
+	"context"
+
+	"oss.terrastruct.com/xdefer"
+
+	"oss.terrastruct.com/d2/d2format"
+	"oss.terrastruct.com/d2/d2parser"
+	"oss.terrastruct.com/d2/lib/xmain"
+)
+
+func fmtCmd(ctx context.Context, ms *xmain.State) (err error) {
+	defer xdefer.Errorf(&err, "failed to fmt")
+
+	ms.Opts = xmain.NewOpts(ms.Env, ms.Log, ms.Opts.Flags.Args()[1:])
+	if len(ms.Opts.Args) == 0 {
+		return xmain.UsageErrorf("fmt must be passed the file to be formatted")
+	} else if len(ms.Opts.Args) > 1 {
+		return xmain.UsageErrorf("fmt accepts only one argument for the file to be formatted")
+	}
+
+	inputPath := ms.Opts.Args[0]
+	input, err := ms.ReadPath(inputPath)
+	if err != nil {
+		return err
+	}
+
+	m, err := d2parser.Parse(inputPath, bytes.NewReader(input), nil)
+	if err != nil {
+		return err
+	}
+
+	return ms.WritePath(inputPath, []byte(d2format.Format(m)))
+}
diff --git a/help.go b/help.go
index 6c1cec897..6f2f93637 100644
--- a/help.go
+++ b/help.go
@@ -15,7 +15,9 @@ import (
 
 func help(ms *xmain.State) {
 	fmt.Fprintf(ms.Stdout, `Usage:
-  %s [--watch=false] [--theme=0] file.d2 [file.svg | file.png]
+  %[1]s [--watch=false] [--theme=0] file.d2 [file.svg | file.png]
+  %[1]s layout [name]
+  %[1]s fmt file.d2
 
 %[1]s compiles and renders file.d2 to file.svg | file.png
 It defaults to file.svg if an output path is not provided.
@@ -29,13 +31,14 @@ Flags:
 
 Subcommands:
   %[1]s layout - Lists available layout engine options with short help
-  %[1]s layout [layout name] - Display long help for a particular layout engine
+  %[1]s layout [name] - Display long help for a particular layout engine
+  %[1]s fmt file.d2 - Format file.d2
 
 See more docs and the source code at https://oss.terrastruct.com/d2
-`, ms.Name, ms.Opts.Defaults())
+`, filepath.Base(ms.Name), ms.Opts.Defaults())
 }
 
-func layoutHelp(ctx context.Context, ms *xmain.State) error {
+func layoutCmd(ctx context.Context, ms *xmain.State) error {
 	if len(ms.Opts.Flags.Args()) == 1 {
 		return shortLayoutHelp(ctx, ms)
 	} else if len(ms.Opts.Flags.Args()) == 2 {
diff --git a/lib/xmain/xmain.go b/lib/xmain/xmain.go
index 80de10137..b0a1aeb3a 100644
--- a/lib/xmain/xmain.go
+++ b/lib/xmain/xmain.go
@@ -66,10 +66,10 @@ func Main(run RunFunc) {
 		}
 
 		if msg != "" {
-			if usage {
-				msg = fmt.Sprintf("%s\n%s", msg, "Run with --help to see usage.")
-			}
 			ms.Log.Error.Print(msg)
+			if usage {
+				ms.Log.Error.Print("Run with --help to see usage.")
+			}
 		}
 		os.Exit(code)
 	}
diff --git a/main.go b/main.go
index 81f8aaab0..29ace7b16 100644
--- a/main.go
+++ b/main.go
@@ -65,18 +65,26 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 		return xmain.UsageErrorf("failed to parse flags: %v", err)
 	}
 
-	if len(ms.Opts.Flags.Args()) > 0 {
-		switch ms.Opts.Flags.Arg(0) {
-		case "layout":
-			return layoutHelp(ctx, ms)
-		}
-	}
-
 	if errors.Is(err, pflag.ErrHelp) {
 		help(ms)
 		return nil
 	}
 
+	if len(ms.Opts.Flags.Args()) > 0 {
+		switch ms.Opts.Flags.Arg(0) {
+		case "layout":
+			return layoutCmd(ctx, ms)
+		case "fmt":
+			return fmtCmd(ctx, ms)
+		case "version":
+			if len(ms.Opts.Flags.Args()) > 1 {
+				return xmain.UsageErrorf("version subcommand accepts no arguments")
+			}
+			fmt.Println(version.Version)
+			return nil
+		}
+	}
+
 	if *debugFlag {
 		ms.Env.Setenv("DEBUG", "1")
 	}
@@ -96,10 +104,6 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 	}
 
 	if len(ms.Opts.Flags.Args()) >= 1 {
-		if ms.Opts.Flags.Arg(0) == "version" {
-			fmt.Println(version.Version)
-			return nil
-		}
 		inputPath = ms.Opts.Flags.Arg(0)
 	}
 	if len(ms.Opts.Flags.Args()) >= 2 {