diff --git a/cmd/decode.go b/cmd/decode.go
new file mode 100644
index 0000000..ab53b62
--- /dev/null
+++ b/cmd/decode.go
@@ -0,0 +1,85 @@
+package cmd
+
+import (
+	"bufio"
+	"bytes"
+	"compress/zlib"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+func Decode(_ *cobra.Command, args []string) {
+	input := args[0]
+	if input == "-" {
+		reader := bufio.NewReader(os.Stdin)
+		DecodeFromReader(reader)
+	} else {
+		DecodeFromInput(input)
+	}
+}
+
+func DecodeFromReader(reader io.Reader) {
+	text, err := GetTextFromReader(reader)
+	if err != nil {
+		exit(err)
+	}
+	result, err := DecodeInput(text)
+	if err != nil {
+		exit(err)
+	}
+	fmt.Println(result)
+}
+
+func DecodeFromInput(input string) {
+	result, err := DecodeInput(input)
+	if err != nil {
+		exit(err)
+	}
+	fmt.Println(result)
+}
+
+// takes a string encoded using deflate + base64 format and returns a decoded string
+func DecodeInput(input string) (string, error) {
+	// special case to extract the encoded diagram from a URL (GET request)
+	// expected format is: https://kroki.io/diagram/format/encoded
+	if strings.HasPrefix(input, "https://") || strings.HasPrefix(input, "http://") {
+		inputUrl, _ := getUrl(input)
+		if inputUrl != nil {
+			// get the last part of the URL
+			input = path.Base(inputUrl.Path)
+		}
+	}
+	result, err := base64.URLEncoding.DecodeString(input)
+	if err != nil {
+		return "", errors.Wrap(err, "fail to decode the input")
+	}
+	reader, err := zlib.NewReader(bytes.NewReader(result))
+	if err != nil {
+		return "", errors.Wrap(err, "fail to create the reader")
+	}
+	out := new(strings.Builder)
+	_, _ = io.Copy(out, reader)
+	return out.String(), nil
+}
+
+func getUrl(input string) (*url.URL, error) {
+	_, err := url.ParseRequestURI(input)
+	if err != nil {
+		return nil, err
+	}
+
+	u, err := url.Parse(input)
+	if err != nil || u.Scheme == "" || u.Host == "" {
+		return u, errors.New("invalid URL")
+	}
+
+	return u, nil
+}
diff --git a/cmd/decode_test.go b/cmd/decode_test.go
new file mode 100644
index 0000000..3463d13
--- /dev/null
+++ b/cmd/decode_test.go
@@ -0,0 +1,36 @@
+package cmd
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestDecodeFromReader(t *testing.T) {
+	cases := []struct {
+		input    string
+		expected string
+	}{
+		{
+			input:    "eNpKyUwvSizIUHBXqPZIzcnJ17ULzy_KSakFBAAA__9sQAjG",
+			expected: "digraph G {Hello->World}\n",
+		},
+		{
+			input:    "https://kroki.io/graphviz/svg/eNpKyUwvSizIUHBXqPZIzcnJ17ULzy_KSakFBAAA__9sQAjG",
+			expected: "digraph G {Hello->World}\n",
+		},
+		{
+			input:    "http://localhost:8000/graphviz/svg/eNpKyUwvSizIUHBXqPZIzcnJ17ULzy_KSakFBAAA__9sQAjG",
+			expected: "digraph G {Hello->World}\n",
+		},
+	}
+	for _, c := range cases {
+		buf := bytes.NewBuffer([]byte(""))
+		buf.Write([]byte(c.input))
+		result := CaptureOutput(func() {
+			DecodeFromReader(buf)
+		})
+		if result != c.expected {
+			t.Errorf("DecodeFromReader error\nexpected: %s\nactual:   %s", c.expected, result)
+		}
+	}
+}
diff --git a/cmd/root.go b/cmd/root.go
index a3eba38..d3f38aa 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -30,6 +30,13 @@ var encodeCmd = &cobra.Command{
 	Run:   Encode,
 }
 
+var decodeCmd = &cobra.Command{
+	Use:   "decode input",
+	Short: "Decode an encoded (deflate + base64) diagram",
+	Args:  cobra.ExactArgs(1),
+	Run:   Decode,
+}
+
 var versionCmd = &cobra.Command{
 	Use:   "version",
 	Short: "Print the version of kroki",
@@ -56,6 +63,7 @@ func init() {
 	RootCmd.AddCommand(versionCmd)
 	RootCmd.AddCommand(convertCmd)
 	RootCmd.AddCommand(encodeCmd)
+	RootCmd.AddCommand(decodeCmd)
 
 	SetupConfig()
 
diff --git a/go.sum b/go.sum
index c5b5d8c..9c0e687 100644
--- a/go.sum
+++ b/go.sum
@@ -40,6 +40,8 @@ github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljT
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yuzutech/kroki-go v0.5.0 h1:XWmxmG22/7PXsqt1TihYjYqmAcs3AO3JtvuwGF20Ehs=
 github.com/yuzutech/kroki-go v0.5.0/go.mod h1:Cys0gjXdlViePdrZ4AKMUyX4yVIAoIhMBhvpYPJahrk=
+github.com/yuzutech/kroki-go v0.5.0 h1:XWmxmG22/7PXsqt1TihYjYqmAcs3AO3JtvuwGF20Ehs=
+github.com/yuzutech/kroki-go v0.5.0/go.mod h1:Cys0gjXdlViePdrZ4AKMUyX4yVIAoIhMBhvpYPJahrk=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a h1:1n5lsVfiQW3yfsRGu98756EH1YthsFqr/5mxHduZW2A=
 golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=