diff --git a/app/rest/auth/providers.go b/app/rest/auth/providers.go
index f1b42661..f08542f2 100644
--- a/app/rest/auth/providers.go
+++ b/app/rest/auth/providers.go
@@ -54,7 +54,7 @@ func NewGithub(p Params) Provider {
 				userInfo.Name = data.value("login")
 			}
 			if userInfo.Name == "" {
-				userInfo.Name = userInfo.ID
+				userInfo.Name = userInfo.ID[0:16]
 			}
 			return userInfo
 		},
@@ -87,7 +87,7 @@ func NewFacebook(p Params) Provider {
 				Name: data.value("name"),
 			}
 			if userInfo.Name == "" {
-				userInfo.Name = userInfo.ID
+				userInfo.Name = userInfo.ID[0:16]
 			}
 
 			uinfoJSON := uinfo{}
diff --git a/app/rest/auth/providers_test.go b/app/rest/auth/providers_test.go
new file mode 100644
index 00000000..103d93a9
--- /dev/null
+++ b/app/rest/auth/providers_test.go
@@ -0,0 +1,62 @@
+package auth
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/umputun/remark/app/store"
+)
+
+func TestProviders_NewGoogle(t *testing.T) {
+	r := NewGoogle(Params{RemarkURL: "http://demo.remark42.com", Cid: "cid", Csecret: "cs"})
+	assert.Equal(t, "google", r.Name)
+
+	udata := userData{"email": "xyz@mail.com", "name": "test user", "picture": "http://demo.remark42.com/blah.png"}
+	user := r.MapUser(udata, nil)
+	assert.Equal(t, store.User{Name: "test user", ID: "google_4578b610e8ad06d15e78379516a035a99de6a4d8",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+
+	// no name in data
+	udata = userData{"email": "xyz@mail.com", "picture": "http://demo.remark42.com/blah.png"}
+	user = r.MapUser(udata, nil)
+	assert.Equal(t, store.User{Name: "xyz", ID: "google_4578b610e8ad06d15e78379516a035a99de6a4d8",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+}
+
+func TestProviders_NewGithub(t *testing.T) {
+	r := NewGithub(Params{RemarkURL: "http://demo.remark42.com", Cid: "cid", Csecret: "cs"})
+	assert.Equal(t, "github", r.Name)
+
+	udata := userData{"login": "lll", "name": "test user", "avatar_url": "http://demo.remark42.com/blah.png"}
+	user := r.MapUser(udata, nil)
+	assert.Equal(t, store.User{Name: "test user", ID: "github_e80b2d2608711cbb3312db7c4727a46fbad9601a",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+
+	// nil name in data
+	udata = userData{"login": "lll", "name": "<nil>", "avatar_url": "http://demo.remark42.com/blah.png"}
+	user = r.MapUser(udata, nil)
+	assert.Equal(t, store.User{Name: "lll", ID: "github_e80b2d2608711cbb3312db7c4727a46fbad9601a",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+
+	// no name in data
+	udata = userData{"login": "lll", "avatar_url": "http://demo.remark42.com/blah.png"}
+	user = r.MapUser(udata, nil)
+	assert.Equal(t, store.User{Name: "github_e80b2d260", ID: "github_e80b2d2608711cbb3312db7c4727a46fbad9601a",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+}
+
+func TestProviders_NewFacebook(t *testing.T) {
+	r := NewFacebook(Params{RemarkURL: "http://demo.remark42.com", Cid: "cid", Csecret: "cs"})
+	assert.Equal(t, "facebook", r.Name)
+
+	udata := userData{"id": "myid", "name": "test user"}
+	user := r.MapUser(udata, []byte(`{"picture": {"data": {"url": "http://demo.remark42.com/blah.png"} }}`))
+	assert.Equal(t, store.User{Name: "test user", ID: "facebook_6e34471f84557e1713012d64a7477c71bfdac631",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+
+	udata = userData{"id": "myid", "name": ""}
+	user = r.MapUser(udata, []byte(`{"picture": {"data": {"url": "http://demo.remark42.com/blah.png"} }}`))
+	assert.Equal(t, store.User{Name: "facebook_6e34471", ID: "facebook_6e34471f84557e1713012d64a7477c71bfdac631",
+		Picture: "http://demo.remark42.com/blah.png", Admin: false, Blocked: false, IP: ""}, user, "got %+v", user)
+
+}