diff --git a/go.mod b/go.mod
index a14bdac0..ccc17a36 100644
--- a/go.mod
+++ b/go.mod
@@ -1,9 +1,11 @@
 module github.com/schollz/croc/v6
 
 require (
+	github.com/cespare/xxhash v1.1.0
 	github.com/cihub/seelog v0.0.0-20170130134532-f561c5e57575
 	github.com/denisbrodbeck/machineid v1.0.1
 	github.com/fatih/color v1.7.0 // indirect
+	github.com/kalafut/imohash v1.0.0
 	github.com/mattn/go-colorable v0.1.1 // indirect
 	github.com/mattn/go-isatty v0.0.7 // indirect
 	github.com/pkg/errors v0.8.1
diff --git a/go.sum b/go.sum
index a14f75bd..9a4b7836 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,7 @@
+github.com/OneOfOne/xxhash v1.2.2 h1:KMrpdQIwFcEqXDklaen+P1axHaj9BSKzvpUUfnHldSE=
+github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
+github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
+github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cihub/seelog v0.0.0-20170130134532-f561c5e57575 h1:kHaBemcxl8o/pQ5VM1c8PVE1PubbNx3mjUr09OqWGCs=
 github.com/cihub/seelog v0.0.0-20170130134532-f561c5e57575/go.mod h1:9d6lWj8KzO/fd/NrVaLscBKmPigpZpn5YawRPw+e3Yo=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -7,6 +11,8 @@ github.com/denisbrodbeck/machineid v1.0.1 h1:geKr9qtkB876mXguW2X6TU4ZynleN6ezuMS
 github.com/denisbrodbeck/machineid v1.0.1/go.mod h1:dJUwb7PTidGDeYyUBmXZ2GphQBbjJCrnectwCyxcUSI=
 github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
+github.com/kalafut/imohash v1.0.0 h1:LgCJ+p/BwM2HKpOxFopkeddpzVCfm15EtXMroXD1SYE=
+github.com/kalafut/imohash v1.0.0/go.mod h1:c3RHT80ZAp5C/aYgQI92ZlrOymqkZnRDprU87kg75HI=
 github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
 github.com/mattn/go-isatty v0.0.5/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
@@ -30,6 +36,8 @@ github.com/schollz/progressbar/v2 v2.12.1 h1:0Ce7IBClG+s3lxXN1Noqwh7aToKGL5a3mnM
 github.com/schollz/progressbar/v2 v2.12.1/go.mod h1:fBI3onORwtNtwCWJHsrXtjE3QnJOtqIZrvr3rDaF7L0=
 github.com/schollz/spinner v0.0.0-20180925172146-6bbc5f7804f9 h1:y08o5oQ/slxXE/F0uh5dd8mdVvb+w4NLcNSDSq4c2F0=
 github.com/schollz/spinner v0.0.0-20180925172146-6bbc5f7804f9/go.mod h1:kCMoQsqzx4MzGJWaALr6tKyCnlrY0kILGLkA1FOiLF4=
+github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72 h1:qLC7fQah7D6K1B0ujays3HV9gkFtllcxhzImRR7ArPQ=
+github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
@@ -57,3 +65,5 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/tylerb/is.v1 v1.1.2 h1:AB/MANFml2ySf+adwcinvajyHvsYltAOD+rb/8njfSU=
+gopkg.in/tylerb/is.v1 v1.1.2/go.mod h1:9yQB2tyIhZ5oph6Kk5Sq7cJMd9c5Jpa1p3hr9kxzPqo=
diff --git a/src/utils/utils.go b/src/utils/utils.go
index 55e411cc..5debe330 100644
--- a/src/utils/utils.go
+++ b/src/utils/utils.go
@@ -2,6 +2,7 @@ package utils
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/md5"
 	"crypto/rand"
 	"crypto/sha256"
@@ -9,13 +10,14 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
-	"bytes"
-	"net"
 	"math"
+	"net"
 	"net/http"
 	"os"
 	"strings"
 
+	"github.com/cespare/xxhash"
+	"github.com/kalafut/imohash"
 	"github.com/schollz/mnemonicode"
 )
 
@@ -37,8 +39,12 @@ func GetInput(prompt string) string {
 	return strings.TrimSpace(text)
 }
 
-// HashFile returns the md5 hash of a file
+// HashFile returns the hash of a file
 func HashFile(fname string) (hash256 []byte, err error) {
+	return IMOHashFile(fname)
+}
+
+func MD5HashFile(fname string) (hash256 []byte, err error) {
 	f, err := os.Open(fname)
 	if err != nil {
 		return
@@ -54,6 +60,30 @@ func HashFile(fname string) (hash256 []byte, err error) {
 	return
 }
 
+// IMOHashFile returns imohash
+func IMOHashFile(fname string) (hash []byte, err error) {
+	b, err := imohash.SumFile(fname)
+	hash = b[:]
+	return
+}
+
+// XXHashFile returns the xxhash of a file
+func XXHashFile(fname string) (hash256 []byte, err error) {
+	f, err := os.Open(fname)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+
+	h := xxhash.New()
+	if _, err = io.Copy(h, f); err != nil {
+		return
+	}
+
+	hash256 = h.Sum(nil)
+	return
+}
+
 // SHA256 returns sha256 sum
 func SHA256(s string) string {
 	sha := sha256.New()
@@ -112,8 +142,6 @@ func ByteCountDecimal(b int64) string {
 	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "kMGTPE"[exp])
 }
 
-
-
 // MissingChunks returns the positions of missing chunks.
 // If file doesn't exist, it returns an empty chunk list (all chunks).
 // If the file size is not the same as requested, it returns an empty chunk list (all chunks).
diff --git a/src/utils/utils_test.go b/src/utils/utils_test.go
index a3e0e1f3..179540c0 100644
--- a/src/utils/utils_test.go
+++ b/src/utils/utils_test.go
@@ -2,24 +2,60 @@ package utils
 
 import (
 	"fmt"
+	"io/ioutil"
+	"math/rand"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
-// Exists reports whether the named file or directory exists.
+func init() {
+	rand.Seed(0)
+	bigBuff := make([]byte, 75000000)
+	rand.Read(bigBuff)
+	ioutil.WriteFile("bigfile.test", bigBuff, 0666)
+}
+
+func BenchmarkMD5(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		MD5HashFile("bigfile.test")
+	}
+}
+
+func BenchmarkXXHash(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		XXHashFile("bigfile.test")
+	}
+}
+func BenchmarkImoHash(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		IMOHashFile("bigfile.test")
+	}
+}
+
 func TestExists(t *testing.T) {
-	assert.True(t, Exists("utils.go"))
+	assert.True(t, Exists("bigfile.test"))
+	assert.False(t, Exists("doesnotexist"))
 }
 
-// HashFile returns the md5 hash of a file
-func TestHashFile(t *testing.T) {
-	b, err := HashFile("utils.go")
+func TestMD5HashFile(t *testing.T) {
+	b, err := MD5HashFile("bigfile.test")
 	assert.Nil(t, err)
-	assert.Equal(t, "314965d4170cd0c70bd2e4f6c977750a", fmt.Sprintf("%x", b))
+	assert.Equal(t, "9fed05acbacbc6a36555c998501c21f6", fmt.Sprintf("%x", b))
+}
+
+func TestIMOHashFile(t *testing.T) {
+	b, err := IMOHashFile("bigfile.test")
+	assert.Nil(t, err)
+	assert.Equal(t, "c0d1e123a96a598ea801cc503d3db8c0", fmt.Sprintf("%x", b))
+}
+
+func TestXXHashFile(t *testing.T) {
+	b, err := XXHashFile("bigfile.test")
+	assert.Nil(t, err)
+	assert.Equal(t, "f2da6ee7e75e8324", fmt.Sprintf("%x", b))
 }
 
-// SHA256 returns sha256 sum
 func TestSHA256(t *testing.T) {
 	assert.Equal(t, "09ca7e4eaa6e8ae9c7d261167129184883644d07dfba7cbfbc4c8a2e08360d5b", SHA256("hello, world"))
 }