diff --git a/dir.go b/dir.go
index 4a18ccb..1f0545b 100644
--- a/dir.go
+++ b/dir.go
@@ -134,7 +134,7 @@ func (d *Dir) manipulate(cfg *Config) error {
 }
 
 // write writes the Dir to the provided destination path.
-func (d *Dir) write(dstDir string, format outputFormat, cfg *Config) error {
+func (d *Dir) write(dstDir string, format Format, cfg *Config) error {
 	// Create the directory
 	dirPath := pathpkg.Join(dstDir, d.Path)
 	if err := os.MkdirAll(dirPath, 0755); err != nil {
@@ -156,7 +156,7 @@ func (d *Dir) write(dstDir string, format outputFormat, cfg *Config) error {
 
 	// Write pages
 	for _, page := range d.Pages {
-		path, content := format(page, cfg)
+		path, content := format.Format(page, cfg)
 		dstPath := pathpkg.Join(dstDir, path)
 		dir := pathpkg.Dir(dstPath)
 		os.MkdirAll(dir, 0755)
@@ -171,7 +171,7 @@ func (d *Dir) write(dstDir string, format outputFormat, cfg *Config) error {
 
 	// Write the index file
 	if d.index != nil {
-		path, content := format(d.index, cfg)
+		path, content := format.Format(d.index, cfg)
 		dstPath := pathpkg.Join(dstDir, path)
 		dir := pathpkg.Dir(dstPath)
 		os.MkdirAll(dir, 0755)
diff --git a/format.go b/format.go
new file mode 100644
index 0000000..e27fe34
--- /dev/null
+++ b/format.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"bytes"
+	pathpkg "path"
+	"strings"
+
+	"git.sr.ht/~adnano/go-gemini"
+)
+
+// Format represents an output format.
+type Format interface {
+	Format(*Page, *Config) (path string, content []byte)
+}
+
+type FormatFunc func(*Page, *Config) (string, []byte)
+
+func (f FormatFunc) Format(p *Page, cfg *Config) (string, []byte) {
+	return f(p, cfg)
+}
+
+// FormatGemini formats the page as Gemini text.
+func FormatGemini(p *Page, cfg *Config) (path string, content []byte) {
+	path = pathpkg.Join(path, "index.gmi")
+	content = []byte(p.Content)
+	return
+}
+
+// FormatHTML formats the page as HTML.
+func FormatHTML(p *Page, cfg *Config) (path string, content []byte) {
+	path = pathpkg.Join(p.Path, "index.html")
+
+	r := strings.NewReader(p.Content)
+	text := gemini.ParseText(r)
+	content = textToHTML(text)
+
+	// html template context
+	type htmlCtx struct {
+		Title   string // page title
+		Content string // page HTML contents
+	}
+
+	var b bytes.Buffer
+	// clean path to remove trailing slash
+	dir := pathpkg.Dir(pathpkg.Clean(p.Path))
+	tmpl := cfg.Templates.FindTemplate(dir, "output.html")
+	tmpl.Execute(&b, &htmlCtx{
+		Title:   p.Title,
+		Content: string(content),
+	})
+	content = b.Bytes()
+	return
+}
diff --git a/main.go b/main.go
index 74a89dc..617710e 100644
--- a/main.go
+++ b/main.go
@@ -1,13 +1,8 @@
 package main
 
 import (
-	"bytes"
 	"flag"
 	"log"
-	pathpkg "path"
-	"strings"
-
-	"git.sr.ht/~adnano/go-gemini"
 )
 
 func main() {
@@ -21,16 +16,6 @@ func run() error {
 	flag.StringVar(&format, "format", "gemini", "output format to use. Supported formats include gemini and html")
 	flag.Parse()
 
-	var output outputFormat
-	switch format {
-	case "gemini":
-		output = outputGemini
-	case "html":
-		output = outputHTML
-	default:
-		log.Fatalf("unknown output format %q", format)
-	}
-
 	// Load config
 	cfg := NewConfig()
 	if err := cfg.Load("config.ini"); err != nil {
@@ -40,6 +25,16 @@ func run() error {
 		return err
 	}
 
+	var output Format
+	switch format {
+	case "gemini":
+		output = FormatFunc(FormatGemini)
+	case "html":
+		output = FormatFunc(FormatHTML)
+	default:
+		log.Fatalf("unknown output format %q", format)
+	}
+
 	// Load content
 	dir := NewDir("")
 	if err := dir.read("content", ""); err != nil {
@@ -56,39 +51,3 @@ func run() error {
 	}
 	return nil
 }
-
-// outputFormat represents an output format.
-type outputFormat func(*Page, *Config) (path string, content []byte)
-
-// outputGemini outputs the page as Gemini text.
-func outputGemini(p *Page, cfg *Config) (path string, content []byte) {
-	path = p.Path + "index.gmi"
-	content = []byte(p.Content)
-	return
-}
-
-// outputHTML outputs the page as HTML.
-func outputHTML(p *Page, cfg *Config) (path string, content []byte) {
-	path = p.Path + "index.html"
-
-	r := strings.NewReader(p.Content)
-	text := gemini.ParseText(r)
-	content = textToHTML(text)
-
-	// html template context
-	type htmlCtx struct {
-		Title   string // page title
-		Content string // page HTML contents
-	}
-
-	var b bytes.Buffer
-	// clean path to remove trailing slash
-	dir := pathpkg.Dir(pathpkg.Clean(p.Path))
-	tmpl := cfg.Templates.FindTemplate(dir, "output.html")
-	tmpl.Execute(&b, &htmlCtx{
-		Title:   p.Title,
-		Content: string(content),
-	})
-	content = b.Bytes()
-	return
-}