diff --git a/archive.go b/archive.go
index 0eedee5..ec62780 100644
--- a/archive.go
+++ b/archive.go
@@ -17,7 +17,7 @@ import (
 
 type ArchiveOption struct {
 	Src  string `help:"function zip archive or src dir" default:"."`
-	Dest string `help:"destination file path" default:"archive.zip"`
+	Dest string `help:"destination file path" default:"function.zip"`
 
 	ExcludeFileOption
 }
diff --git a/diff.go b/diff.go
index c32343d..f99b7d4 100644
--- a/diff.go
+++ b/diff.go
@@ -9,8 +9,12 @@ import (
 	"strings"
 
 	"github.com/fatih/color"
+	"github.com/hexops/gotextdiff"
+	"github.com/hexops/gotextdiff/myers"
+	"github.com/hexops/gotextdiff/span"
 	"github.com/kylelemons/godebug/diff"
 
+	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/service/lambda"
 	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
 )
@@ -19,6 +23,8 @@ import (
 type DiffOption struct {
 	Src        string `help:"function zip archive or src dir" default:"."`
 	CodeSha256 bool   `help:"diff of code sha256" default:"false"`
+	Unified    bool   `help:"unified diff" default:"true" negatable:"" short:"u"`
+	Qualifier  string `help:"compare with" default:"$LATEST"`
 
 	ExcludeFileOption
 }
@@ -44,12 +50,23 @@ func (app *App) Diff(ctx context.Context, opt *DiffOption) error {
 	var packageType types.PackageType
 	if res, err := app.lambda.GetFunction(ctx, &lambda.GetFunctionInput{
 		FunctionName: &name,
+		Qualifier:    &opt.Qualifier,
 	}); err != nil {
 		return fmt.Errorf("failed to GetFunction %s: %w", name, err)
 	} else {
 		latest = res.Configuration
 		code = res.Code
-		tags = res.Tags
+		{
+			res, err := app.lambda.ListTags(ctx, &lambda.ListTagsInput{
+				// Tagging operations are permitted on Lambda functions only.
+				// Tags on aliases and versions are not supported.
+				Resource: aws.String(app.functionArn(ctx, name)),
+			})
+			if err != nil {
+				return fmt.Errorf("faled to list tags: %w", err)
+			}
+			tags = res.Tags
+		}
 		currentCodeSha256 = *res.Configuration.CodeSha256
 		packageType = res.Configuration.PackageType
 	}
@@ -57,11 +74,19 @@ func (app *App) Diff(ctx context.Context, opt *DiffOption) error {
 
 	latestJSON, _ := marshalJSON(latestFunc)
 	newJSON, _ := marshalJSON(newFunc)
+	remoteArn := app.functionArn(ctx, name) + ":" + opt.Qualifier
 
-	if ds := diff.Diff(string(latestJSON), string(newJSON)); ds != "" {
-		fmt.Println(color.RedString("---" + app.functionArn(ctx, name)))
-		fmt.Println(color.GreenString("+++" + app.functionFilePath))
-		fmt.Println(coloredDiff(ds))
+	if opt.Unified {
+		edits := myers.ComputeEdits(span.URIFromPath(remoteArn), string(latestJSON), string(newJSON))
+		if ds := fmt.Sprint(gotextdiff.ToUnified(remoteArn, app.functionFilePath, string(latestJSON), edits)); ds != "" {
+			fmt.Print(coloredDiff(ds))
+		}
+	} else {
+		if ds := diff.Diff(string(latestJSON), string(newJSON)); ds != "" {
+			fmt.Println(color.RedString("---" + remoteArn))
+			fmt.Println(color.GreenString("+++" + app.functionFilePath))
+			fmt.Print(coloredDiff(ds))
+		}
 	}
 
 	if err := validateUpdateFunction(latest, code, newFunc); err != nil {
diff --git a/go.mod b/go.mod
index 6142920..4f179f1 100644
--- a/go.mod
+++ b/go.mod
@@ -18,6 +18,7 @@ require (
 	github.com/google/go-cmp v0.5.9
 	github.com/google/go-jsonnet v0.20.0
 	github.com/hashicorp/go-envparse v0.0.0-20200406174449-d9cfd743a15e
+	github.com/hexops/gotextdiff v1.0.3
 	github.com/kayac/go-config v0.6.0
 	github.com/kylelemons/godebug v1.1.0
 	github.com/mattn/go-isatty v0.0.17
diff --git a/go.sum b/go.sum
index 9605b1b..5ff08a9 100644
--- a/go.sum
+++ b/go.sum
@@ -269,6 +269,7 @@ github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ
 github.com/hashicorp/jsonapi v0.0.0-20210826224640-ee7dae0fb22d h1:9ARUJJ1VVynB176G1HCwleORqCaXm/Vx0uUi0dL26I0=
 github.com/hashicorp/jsonapi v0.0.0-20210826224640-ee7dae0fb22d/go.mod h1:Yog5+CPEM3c99L1CL2CFCYoSzgWm5vTU58idbRUaLik=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/itchyny/gojq v0.12.11 h1:YhLueoHhHiN4mkfM+3AyJV6EPcCxKZsOnYf+aVSwaQw=