diff --git a/cmd/cache.go b/cmd/cache.go
new file mode 100644
index 0000000..f249188
--- /dev/null
+++ b/cmd/cache.go
@@ -0,0 +1,102 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/Snider/Borg/pkg/cache"
+	"github.com/spf13/cobra"
+)
+
+// cacheCmd represents the cache command
+var cacheCmd = NewCacheCmd()
+var cacheStatsCmd = NewCacheStatsCmd()
+var cacheClearCmd = NewCacheClearCmd()
+
+func init() {
+	RootCmd.AddCommand(GetCacheCmd())
+	GetCacheCmd().AddCommand(GetCacheStatsCmd())
+	GetCacheCmd().AddCommand(GetCacheClearCmd())
+}
+
+func GetCacheCmd() *cobra.Command {
+	return cacheCmd
+}
+
+func GetCacheStatsCmd() *cobra.Command {
+	return cacheStatsCmd
+}
+
+func GetCacheClearCmd() *cobra.Command {
+	return cacheClearCmd
+}
+
+func NewCacheCmd() *cobra.Command {
+	cacheCmd := &cobra.Command{
+		Use:   "cache",
+		Short: "Manage the cache",
+		Long:  `Manage the cache.`,
+	}
+	return cacheCmd
+}
+
+func NewCacheStatsCmd() *cobra.Command {
+	cacheStatsCmd := &cobra.Command{
+		Use:   "stats",
+		Short: "Show cache stats",
+		Long:  `Show cache stats.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cacheDir, err := GetCacheDir(cmd)
+			if err != nil {
+				return err
+			}
+			cacheInstance, err := cache.New(cacheDir)
+			if err != nil {
+				return fmt.Errorf("failed to create cache: %w", err)
+			}
+
+			size, err := cacheInstance.Size()
+			if err != nil {
+				return fmt.Errorf("failed to get cache size: %w", err)
+			}
+
+			fmt.Printf("Cache directory: %s\n", cacheInstance.Dir())
+			fmt.Printf("Number of entries: %d\n", cacheInstance.NumEntries())
+			fmt.Printf("Total size: %d bytes\n", size)
+
+			return nil
+		},
+	}
+	cacheStatsCmd.Flags().String("cache-dir", "", "Custom cache location")
+	return cacheStatsCmd
+}
+
+func NewCacheClearCmd() *cobra.Command {
+	cacheClearCmd := &cobra.Command{
+		Use:   "clear",
+		Short: "Clear the cache",
+		Long:  `Clear the cache.`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cacheDir, err := GetCacheDir(cmd)
+			if err != nil {
+				return err
+			}
+			cacheInstance, err := cache.New(cacheDir)
+			if err != nil {
+				return fmt.Errorf("failed to create cache: %w", err)
+			}
+
+			err = cacheInstance.Clear()
+			if err != nil {
+				return fmt.Errorf("failed to clear cache: %w", err)
+			}
+
+			fmt.Println("Cache cleared.")
+
+			return nil
+		},
+	}
+	cacheClearCmd.Flags().String("cache-dir", "", "Custom cache location")
+	return cacheClearCmd
+}
diff --git a/cmd/collect_website.go b/cmd/collect_website.go
index 3811f32..d13855b 100644
--- a/cmd/collect_website.go
+++ b/cmd/collect_website.go
@@ -3,8 +3,10 @@ package cmd
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/schollz/progressbar/v3"
+	"github.com/Snider/Borg/pkg/cache"
 	"github.com/Snider/Borg/pkg/compress"
 	"github.com/Snider/Borg/pkg/tim"
 	"github.com/Snider/Borg/pkg/trix"
@@ -51,11 +53,32 @@ func NewCollectWebsiteCmd() *cobra.Command {
 				bar = ui.NewProgressBar(-1, "Crawling website")
 			}
 
-			dn, err := website.DownloadAndPackageWebsite(websiteURL, depth, bar)
+			noCache, _ := cmd.Flags().GetBool("no-cache")
+
+			var cacheInstance *cache.Cache
+			var err error
+			if !noCache {
+				cacheDir, err := GetCacheDir(cmd)
+				if err != nil {
+					return err
+				}
+				cacheInstance, err = cache.New(cacheDir)
+				if err != nil {
+					return fmt.Errorf("failed to create cache: %w", err)
+				}
+			}
+
+			dn, err := website.DownloadAndPackageWebsite(websiteURL, depth, bar, cacheInstance)
 			if err != nil {
 				return fmt.Errorf("error downloading and packaging website: %w", err)
 			}
 
+			if cacheInstance != nil {
+				if err := cacheInstance.Close(); err != nil {
+					return fmt.Errorf("failed to close cache: %w", err)
+				}
+			}
+
 			var data []byte
 			if format == "tim" {
 				tim, err := tim.FromDataNode(dn)
@@ -104,5 +127,7 @@ func NewCollectWebsiteCmd() *cobra.Command {
 	collectWebsiteCmd.PersistentFlags().String("format", "datanode", "Output format (datanode, tim, or trix)")
 	collectWebsiteCmd.PersistentFlags().String("compression", "none", "Compression format (none, gz, or xz)")
 	collectWebsiteCmd.PersistentFlags().String("password", "", "Password for encryption")
+	collectWebsiteCmd.Flags().Bool("no-cache", false, "Skip cache, re-download everything")
+	collectWebsiteCmd.Flags().String("cache-dir", "", "Custom cache location")
 	return collectWebsiteCmd
 }
diff --git a/cmd/collect_website_test.go b/cmd/collect_website_test.go
index 2c39674..6a97128 100644
--- a/cmd/collect_website_test.go
+++ b/cmd/collect_website_test.go
@@ -6,6 +6,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/Snider/Borg/pkg/cache"
 	"github.com/Snider/Borg/pkg/datanode"
 	"github.com/Snider/Borg/pkg/website"
 	"github.com/schollz/progressbar/v3"
@@ -14,7 +15,7 @@ import (
 func TestCollectWebsiteCmd_Good(t *testing.T) {
 	// Mock the website downloader
 	oldDownloadAndPackageWebsite := website.DownloadAndPackageWebsite
-	website.DownloadAndPackageWebsite = func(startURL string, maxDepth int, bar *progressbar.ProgressBar) (*datanode.DataNode, error) {
+	website.DownloadAndPackageWebsite = func(startURL string, maxDepth int, bar *progressbar.ProgressBar, cache *cache.Cache) (*datanode.DataNode, error) {
 		return datanode.New(), nil
 	}
 	defer func() {
@@ -35,7 +36,7 @@ func TestCollectWebsiteCmd_Good(t *testing.T) {
 func TestCollectWebsiteCmd_Bad(t *testing.T) {
 	// Mock the website downloader to return an error
 	oldDownloadAndPackageWebsite := website.DownloadAndPackageWebsite
-	website.DownloadAndPackageWebsite = func(startURL string, maxDepth int, bar *progressbar.ProgressBar) (*datanode.DataNode, error) {
+	website.DownloadAndPackageWebsite = func(startURL string, maxDepth int, bar *progressbar.ProgressBar, cache *cache.Cache) (*datanode.DataNode, error) {
 		return nil, fmt.Errorf("website error")
 	}
 	defer func() {
diff --git a/cmd/root.go b/cmd/root.go
index 9cadb27..b18c3eb 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -2,7 +2,10 @@ package cmd
 
 import (
 	"context"
+	"fmt"
 	"log/slog"
+	"os"
+	"path/filepath"
 
 	"github.com/spf13/cobra"
 )
@@ -28,3 +31,16 @@ func Execute(log *slog.Logger) error {
 	RootCmd.SetContext(context.WithValue(context.Background(), "logger", log))
 	return RootCmd.Execute()
 }
+
+func GetCacheDir(cmd *cobra.Command) (string, error) {
+	cacheDir, _ := cmd.Flags().GetString("cache-dir")
+	if cacheDir != "" {
+		return cacheDir, nil
+	}
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("failed to get user home directory: %w", err)
+	}
+	return filepath.Join(home, ".borg", "cache"), nil
+}
diff --git a/examples/collect_website/main.go b/examples/collect_website/main.go
index 2e2f606..10cb4dc 100644
--- a/examples/collect_website/main.go
+++ b/examples/collect_website/main.go
@@ -11,7 +11,7 @@ func main() {
 	log.Println("Collecting website...")
 
 	// Download and package the website.
-	dn, err := website.DownloadAndPackageWebsite("https://example.com", 2, nil)
+	dn, err := website.DownloadAndPackageWebsite("https://example.com", 2, nil, nil)
 	if err != nil {
 		log.Fatalf("Failed to collect website: %v", err)
 	}
diff --git a/pkg/cache/cache.go b/pkg/cache/cache.go
new file mode 100644
index 0000000..2d78c2f
--- /dev/null
+++ b/pkg/cache/cache.go
@@ -0,0 +1,158 @@
+package cache
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+const (
+	indexFileName   = "index.json"
+	storageDirName  = "sha256"
+)
+
+// Cache provides a content-addressable storage for web content.
+type Cache struct {
+	dir     string
+	index   map[string]string
+	mutex   sync.RWMutex
+}
+
+// New creates a new Cache instance.
+func New(dir string) (*Cache, error) {
+	storageDir := filepath.Join(dir, storageDirName)
+	if err := os.MkdirAll(storageDir, 0755); err != nil {
+		return nil, fmt.Errorf("failed to create cache storage directory: %w", err)
+	}
+
+	cache := &Cache{
+		dir:     dir,
+		index:   make(map[string]string),
+	}
+
+	if err := cache.loadIndex(); err != nil {
+		return nil, fmt.Errorf("failed to load cache index: %w", err)
+	}
+
+	return cache, nil
+}
+
+// Get retrieves content from the cache for a given URL.
+func (c *Cache) Get(url string) ([]byte, bool, error) {
+	c.mutex.RLock()
+	hash, ok := c.index[url]
+	c.mutex.RUnlock()
+
+	if !ok {
+		return nil, false, nil
+	}
+
+	path := c.getStoragePath(hash)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, false, nil
+		}
+		return nil, false, fmt.Errorf("failed to read from cache: %w", err)
+	}
+
+	return data, true, nil
+}
+
+// Put adds content to the cache for a given URL.
+func (c *Cache) Put(url string, data []byte) error {
+	hashBytes := sha256.Sum256(data)
+	hash := fmt.Sprintf("%x", hashBytes)
+
+	path := c.getStoragePath(hash)
+	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+		return fmt.Errorf("failed to create cache directory: %w", err)
+	}
+
+	if err := os.WriteFile(path, data, 0644); err != nil {
+		return fmt.Errorf("failed to write to cache: %w", err)
+	}
+
+	c.mutex.Lock()
+	c.index[url] = hash
+	c.mutex.Unlock()
+
+	return nil
+}
+
+// Close saves the index file.
+func (c *Cache) Close() error {
+	return c.saveIndex()
+}
+
+// Clear removes the cache directory.
+func (c *Cache) Clear() error {
+	return os.RemoveAll(c.dir)
+}
+
+// Dir returns the cache directory.
+func (c *Cache) Dir() string {
+	return c.dir
+}
+
+// Size returns the total size of the cache.
+func (c *Cache) Size() (int64, error) {
+	var size int64
+	err := filepath.Walk(c.dir, func(_ string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !info.IsDir() {
+			size += info.Size()
+		}
+		return nil
+	})
+	return size, err
+}
+
+// NumEntries returns the number of entries in the cache.
+func (c *Cache) NumEntries() int {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+	return len(c.index)
+}
+
+
+func (c *Cache) getStoragePath(hash string) string {
+	return filepath.Join(c.dir, storageDirName, hash[:2], hash)
+}
+
+func (c *Cache) loadIndex() error {
+	indexPath := filepath.Join(c.dir, indexFileName)
+	file, err := os.Open(indexPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	defer file.Close()
+
+	decoder := json.NewDecoder(file)
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	return decoder.Decode(&c.index)
+}
+
+func (c *Cache) saveIndex() error {
+	indexPath := filepath.Join(c.dir, indexFileName)
+	file, err := os.Create(indexPath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	encoder := json.NewEncoder(file)
+	encoder.SetIndent("", "  ")
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	return encoder.Encode(c.index)
+}
diff --git a/pkg/cache/cache_test.go b/pkg/cache/cache_test.go
new file mode 100644
index 0000000..4fa766a
--- /dev/null
+++ b/pkg/cache/cache_test.go
@@ -0,0 +1,87 @@
+package cache
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestCache_Good(t *testing.T) {
+	cacheDir := t.TempDir()
+	c, err := New(cacheDir)
+	if err != nil {
+		t.Fatalf("Failed to create cache: %v", err)
+	}
+
+	// Test Put and Get
+	url := "https://example.com"
+	data := []byte("hello world")
+	err = c.Put(url, data)
+	if err != nil {
+		t.Fatalf("Failed to put data in cache: %v", err)
+	}
+
+	cachedData, ok, err := c.Get(url)
+	if err != nil {
+		t.Fatalf("Failed to get data from cache: %v", err)
+	}
+	if !ok {
+		t.Fatal("Expected data to be in cache, but it wasn't")
+	}
+	if string(cachedData) != string(data) {
+		t.Errorf("Expected data to be '%s', but got '%s'", string(data), string(cachedData))
+	}
+
+	// Test persistence
+	err = c.Close()
+	if err != nil {
+		t.Fatalf("Failed to close cache: %v", err)
+	}
+
+	c2, err := New(cacheDir)
+	if err != nil {
+		t.Fatalf("Failed to create new cache: %v", err)
+	}
+	cachedData, ok, err = c2.Get(url)
+	if err != nil {
+		t.Fatalf("Failed to get data from new cache: %v", err)
+	}
+	if !ok {
+		t.Fatal("Expected data to be in new cache, but it wasn't")
+	}
+	if string(cachedData) != string(data) {
+		t.Errorf("Expected data to be '%s', but got '%s'", string(data), string(cachedData))
+	}
+}
+
+func TestCache_Clear(t *testing.T) {
+	cacheDir := t.TempDir()
+	c, err := New(cacheDir)
+	if err != nil {
+		t.Fatalf("Failed to create cache: %v", err)
+	}
+
+	// Put some data in the cache
+	url := "https://example.com"
+	data := []byte("hello world")
+	err = c.Put(url, data)
+	if err != nil {
+		t.Fatalf("Failed to put data in cache: %v", err)
+	}
+	err = c.Close()
+	if err != nil {
+		t.Fatalf("Failed to close cache: %v", err)
+	}
+
+	// Clear the cache
+	err = c.Clear()
+	if err != nil {
+		t.Fatalf("Failed to clear cache: %v", err)
+	}
+
+	// Check that the cache directory is gone
+	_, err = os.Stat(cacheDir)
+	if !os.IsNotExist(err) {
+		t.Fatal("Expected cache directory to be gone, but it wasn't")
+	}
+}
diff --git a/pkg/website/website.go b/pkg/website/website.go
index b2bd517..3b73827 100644
--- a/pkg/website/website.go
+++ b/pkg/website/website.go
@@ -7,6 +7,7 @@ import (
 	"net/url"
 	"strings"
 
+	"github.com/Snider/Borg/pkg/cache"
 	"github.com/Snider/Borg/pkg/datanode"
 	"github.com/schollz/progressbar/v3"
 
@@ -24,32 +25,34 @@ type Downloader struct {
 	progressBar *progressbar.ProgressBar
 	client      *http.Client
 	errors      []error
+	cache       *cache.Cache
 }
 
 // NewDownloader creates a new Downloader.
-func NewDownloader(maxDepth int) *Downloader {
-	return NewDownloaderWithClient(maxDepth, http.DefaultClient)
+func NewDownloader(maxDepth int, cache *cache.Cache) *Downloader {
+	return NewDownloaderWithClient(maxDepth, http.DefaultClient, cache)
 }
 
 // NewDownloaderWithClient creates a new Downloader with a custom http.Client.
-func NewDownloaderWithClient(maxDepth int, client *http.Client) *Downloader {
+func NewDownloaderWithClient(maxDepth int, client *http.Client, cache *cache.Cache) *Downloader {
 	return &Downloader{
 		dn:          datanode.New(),
 		visited:     make(map[string]bool),
 		maxDepth:    maxDepth,
 		client:      client,
 		errors:      make([]error, 0),
+		cache:       cache,
 	}
 }
 
 // downloadAndPackageWebsite downloads a website and packages it into a DataNode.
-func downloadAndPackageWebsite(startURL string, maxDepth int, bar *progressbar.ProgressBar) (*datanode.DataNode, error) {
+func downloadAndPackageWebsite(startURL string, maxDepth int, bar *progressbar.ProgressBar, cache *cache.Cache) (*datanode.DataNode, error) {
 	baseURL, err := url.Parse(startURL)
 	if err != nil {
 		return nil, err
 	}
 
-	d := NewDownloader(maxDepth)
+	d := NewDownloader(maxDepth, cache)
 	d.baseURL = baseURL
 	d.progressBar = bar
 	d.crawl(startURL, 0)
@@ -69,34 +72,14 @@ func (d *Downloader) crawl(pageURL string, depth int) {
 	if depth > d.maxDepth || d.visited[pageURL] {
 		return
 	}
-	d.visited[pageURL] = true
-	if d.progressBar != nil {
-		d.progressBar.Add(1)
-	}
 
-	resp, err := d.client.Get(pageURL)
-	if err != nil {
-		d.errors = append(d.errors, fmt.Errorf("Error getting %s: %w", pageURL, err))
+	body, contentType := d.download(pageURL)
+	if body == nil {
 		return
 	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode >= 400 {
-		d.errors = append(d.errors, fmt.Errorf("bad status for %s: %s", pageURL, resp.Status))
-		return
-	}
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		d.errors = append(d.errors, fmt.Errorf("Error reading body of %s: %w", pageURL, err))
-		return
-	}
-
-	relPath := d.getRelativePath(pageURL)
-	d.dn.AddData(relPath, body)
 
 	// Don't try to parse non-html content
-	if !strings.HasPrefix(resp.Header.Get("Content-Type"), "text/html") {
+	if !strings.HasPrefix(contentType, "text/html") {
 		return
 	}
 
@@ -136,31 +119,56 @@ func (d *Downloader) downloadAsset(assetURL string) {
 	if d.visited[assetURL] {
 		return
 	}
-	d.visited[assetURL] = true
+	d.download(assetURL)
+}
+
+func (d *Downloader) download(pageURL string) ([]byte, string) {
+	d.visited[pageURL] = true
 	if d.progressBar != nil {
 		d.progressBar.Add(1)
 	}
 
-	resp, err := d.client.Get(assetURL)
+	// Check the cache first
+	if d.cache != nil {
+		data, ok, err := d.cache.Get(pageURL)
+		if err != nil {
+			d.errors = append(d.errors, fmt.Errorf("Error getting from cache %s: %w", pageURL, err))
+			// Don't return, as we can still try to download it
+		}
+		if ok {
+			relPath := d.getRelativePath(pageURL)
+			d.dn.AddData(relPath, data)
+			return data, "" // We don't know the content type from the cache
+		}
+	}
+
+	resp, err := d.client.Get(pageURL)
 	if err != nil {
-		d.errors = append(d.errors, fmt.Errorf("Error getting asset %s: %w", assetURL, err))
-		return
+		d.errors = append(d.errors, fmt.Errorf("Error getting %s: %w", pageURL, err))
+		return nil, ""
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode >= 400 {
-		d.errors = append(d.errors, fmt.Errorf("bad status for asset %s: %s", assetURL, resp.Status))
-		return
+		d.errors = append(d.errors, fmt.Errorf("bad status for %s: %s", pageURL, resp.Status))
+		return nil, ""
 	}
 
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		d.errors = append(d.errors, fmt.Errorf("Error reading body of asset %s: %w", assetURL, err))
-		return
+		d.errors = append(d.errors, fmt.Errorf("Error reading body of %s: %w", pageURL, err))
+		return nil, ""
 	}
 
-	relPath := d.getRelativePath(assetURL)
+	relPath := d.getRelativePath(pageURL)
 	d.dn.AddData(relPath, body)
+
+	// Add to cache
+	if d.cache != nil {
+		d.cache.Put(pageURL, body)
+	}
+
+	return body, resp.Header.Get("Content-Type")
 }
 
 func (d *Downloader) getRelativePath(pageURL string) string {
diff --git a/pkg/website/website_test.go b/pkg/website/website_test.go
index d3685e5..6b0a0f2 100644
--- a/pkg/website/website_test.go
+++ b/pkg/website/website_test.go
@@ -7,9 +7,11 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
+	"github.com/Snider/Borg/pkg/cache"
 	"github.com/schollz/progressbar/v3"
 )
 
@@ -20,7 +22,7 @@ func TestDownloadAndPackageWebsite_Good(t *testing.T) {
 	defer server.Close()
 
 	bar := progressbar.NewOptions(1, progressbar.OptionSetWriter(io.Discard))
-	dn, err := DownloadAndPackageWebsite(server.URL, 2, bar)
+	dn, err := DownloadAndPackageWebsite(server.URL, 2, bar, nil)
 	if err != nil {
 		t.Fatalf("DownloadAndPackageWebsite failed: %v", err)
 	}
@@ -52,7 +54,7 @@ func TestDownloadAndPackageWebsite_Good(t *testing.T) {
 
 func TestDownloadAndPackageWebsite_Bad(t *testing.T) {
 	t.Run("Invalid Start URL", func(t *testing.T) {
-		_, err := DownloadAndPackageWebsite("http://invalid-url", 1, nil)
+		_, err := DownloadAndPackageWebsite("http://invalid-url", 1, nil, nil)
 		if err == nil {
 			t.Fatal("Expected an error for an invalid start URL, but got nil")
 		}
@@ -63,7 +65,7 @@ func TestDownloadAndPackageWebsite_Bad(t *testing.T) {
 			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
 		}))
 		defer server.Close()
-		_, err := DownloadAndPackageWebsite(server.URL, 1, nil)
+		_, err := DownloadAndPackageWebsite(server.URL, 1, nil, nil)
 		if err == nil {
 			t.Fatal("Expected an error for a server error on the start URL, but got nil")
 		}
@@ -80,7 +82,7 @@ func TestDownloadAndPackageWebsite_Bad(t *testing.T) {
 		}))
 		defer server.Close()
 		// We expect an error because the link is broken.
-		dn, err := DownloadAndPackageWebsite(server.URL, 1, nil)
+		dn, err := DownloadAndPackageWebsite(server.URL, 1, nil, nil)
 		if err == nil {
 			t.Fatal("Expected an error for a broken link, but got nil")
 		}
@@ -99,7 +101,7 @@ func TestDownloadAndPackageWebsite_Ugly(t *testing.T) {
 		defer server.Close()
 
 		bar := progressbar.NewOptions(1, progressbar.OptionSetWriter(io.Discard))
-		dn, err := DownloadAndPackageWebsite(server.URL, 1, bar) // Max depth of 1
+		dn, err := DownloadAndPackageWebsite(server.URL, 1, bar, nil) // Max depth of 1
 		if err != nil {
 			t.Fatalf("DownloadAndPackageWebsite failed: %v", err)
 		}
@@ -122,7 +124,7 @@ func TestDownloadAndPackageWebsite_Ugly(t *testing.T) {
 			fmt.Fprint(w, `<a href="http://externalsite.com/page.html">External</a>`)
 		}))
 		defer server.Close()
-		dn, err := DownloadAndPackageWebsite(server.URL, 1, nil)
+		dn, err := DownloadAndPackageWebsite(server.URL, 1, nil, nil)
 		if err != nil {
 			t.Fatalf("DownloadAndPackageWebsite failed: %v", err)
 		}
@@ -156,7 +158,7 @@ func TestDownloadAndPackageWebsite_Ugly(t *testing.T) {
 		// For now, we'll just test that it doesn't hang forever.
 		done := make(chan bool)
 		go func() {
-			_, err := DownloadAndPackageWebsite(server.URL, 1, nil)
+			_, err := DownloadAndPackageWebsite(server.URL, 1, nil, nil)
 			if err != nil && !strings.Contains(err.Error(), "context deadline exceeded") {
 				// We expect a timeout error, but other errors are failures.
 				t.Errorf("unexpected error: %v", err)
@@ -174,6 +176,60 @@ func TestDownloadAndPackageWebsite_Ugly(t *testing.T) {
 
 // --- Helpers ---
 
+func TestDownloadAndPackageWebsite_Cache(t *testing.T) {
+	var requestCount int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&requestCount, 1)
+		switch r.URL.Path {
+		case "/":
+			w.Header().Set("Content-Type", "text/html")
+			fmt.Fprint(w, `<a href="/page2.html">Page 2</a>`)
+		case "/page2.html":
+			w.Header().Set("Content-Type", "text/html")
+			fmt.Fprint(w, `<h1>Page 2</h1>`)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer server.Close()
+
+	cacheDir := t.TempDir()
+	c, err := cache.New(cacheDir)
+	if err != nil {
+		t.Fatalf("Failed to create cache: %v", err)
+	}
+
+	// First download
+	_, err = DownloadAndPackageWebsite(server.URL, 2, nil, c)
+	if err != nil {
+		t.Fatalf("DownloadAndPackageWebsite failed: %v", err)
+	}
+	if err := c.Close(); err != nil {
+		t.Fatalf("Failed to close cache: %v", err)
+	}
+
+	if atomic.LoadInt32(&requestCount) != 2 {
+		t.Errorf("Expected 2 requests to the server, but got %d", requestCount)
+	}
+
+	// Second download
+	c2, err := cache.New(cacheDir)
+	if err != nil {
+		t.Fatalf("Failed to create new cache: %v", err)
+	}
+	_, err = DownloadAndPackageWebsite(server.URL, 2, nil, c2)
+	if err != nil {
+		t.Fatalf("DownloadAndPackageWebsite failed: %v", err)
+	}
+	if err := c2.Close(); err != nil {
+		t.Fatalf("Failed to close cache: %v", err)
+	}
+
+	if atomic.LoadInt32(&requestCount) != 2 {
+		t.Errorf("Expected 2 requests to the server after caching, but got %d", requestCount)
+	}
+}
+
 func newWebsiteTestServer() *httptest.Server {
 	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.URL.Path {