diff --git a/test/onionshare_helpers_test.py b/test/onionshare_helpers_test.py
new file mode 100644
index 00000000..83f78da2
--- /dev/null
+++ b/test/onionshare_helpers_test.py
@@ -0,0 +1,35 @@
+from onionshare import helpers
+from nose import with_setup
+
+import test_helpers
+
+def test_get_platform_on_tails():
+    "get_platform() returns 'Tails' when hostname is 'amnesia'"
+    helpers.platform.uname = lambda: ('Linux', 'amnesia', '3.14-1-amd64', '#1 SMP Debian 3.14.4-1 (2014-05-13)', 'x86_64', '')
+    assert helpers.get_platform() == 'Tails'
+
+def test_get_platform_returns_platform_system():
+    "get_platform() returns platform.system() when ONIONSHARE_PLATFORM is not defined"
+    helpers.platform.system = lambda: 'Sega Saturn'
+    assert helpers.get_platform() == 'Sega Saturn'
+
+def test_filehash_returns_correct_hash():
+    "file_crunching() returns correct hash"
+
+    text = """
+           If you want a picture of the future, imagine a boot stamping on an
+           encrypted, redundant, distributed filesystem -- forever.
+           """
+    tempfile = test_helpers.write_tempfile(text)
+    filehash, _ = helpers.file_crunching(tempfile)
+
+    assert filehash == 'bc004fe72e6530a545570b4c6ce76bcb78ea526b'
+
+def test_filehash_returns_correct_size():
+    "file_crunching() returns correct size"
+
+    text = "AUSCANNZUKUS has always been at war with Eastasia."
+    tempfile = test_helpers.write_tempfile(text)
+    _, filesize = helpers.file_crunching(tempfile)
+
+    assert filesize == 50
diff --git a/test/onionshare_strings_test.py b/test/onionshare_strings_test.py
new file mode 100644
index 00000000..ea20a74a
--- /dev/null
+++ b/test/onionshare_strings_test.py
@@ -0,0 +1,21 @@
+import locale
+from onionshare import strings
+from nose import with_setup
+
+def test_starts_with_empty_strings():
+    "creates an empty strings dict by default"
+    assert strings.strings == {}
+
+def test_load_strings_defaults_to_english():
+    "load_strings() loads English by default"
+    locale.getdefaultlocale = lambda: ('en_US', 'UTF-8')
+    strings.load_strings()
+    assert strings._('calculating_sha1') == "Calculating SHA1 checksum."
+
+def test_load_strings_loads_other_languages():
+    "load_strings() loads other languages in different locales"
+    locale.getdefaultlocale = lambda: ('fr_FR', 'UTF-8')
+    strings.load_strings("fr")
+    assert strings._('calculating_sha1') == "Calculer un hachage SHA-1."
+
+
diff --git a/test/onionshare_test.py b/test/onionshare_test.py
index a0333211..afd955b4 100644
--- a/test/onionshare_test.py
+++ b/test/onionshare_test.py
@@ -1,89 +1,15 @@
-from onionshare import *
-import tempfile
-
-def test_get_platform_on_tails():
-    "get_platform() returns 'Tails' when hostname is 'amnesia'"
-    onionshare.platform.uname = lambda: ('Linux', 'amnesia', '3.14-1-amd64', '#1 SMP Debian 3.14.4-1 (2014-05-13)', 'x86_64', '')
-    assert get_platform() == 'Tails'
-
-def test_get_platform_returns_platform_system():
-    "get_platform() returns platform.system() when ONIONSHARE_PLATFORM is not defined"
-    onionshare.platform.system = lambda: 'Sega Saturn'
-    assert get_platform() == 'Sega Saturn'
-
-class MockSubprocess():
-  def __init__(self):
-      self.last_call = None
-
-  def call(self, args):
-      self.last_call = args
-
-  def last_call_args(self):
-      return self.last_call
-
-def test_load_strings_defaults_to_english():
-    "load_strings() loads English by default"
-    locale.getdefaultlocale = lambda: ('en_US', 'UTF-8')
-    load_strings()
-    assert onionshare.strings['calculating_sha1'] == "Calculating SHA1 checksum."
-
-def test_load_strings_loads_other_languages():
-    "load_strings() loads other languages in different locales"
-    locale.getdefaultlocale = lambda: ('fr_FR', 'UTF-8')
-    load_strings("fr")
-    assert onionshare.strings['calculating_sha1'] == "Calculer un hachage SHA-1."
-
-def test_generate_slug_length():
-    "generates a 26-character slug"
-    assert len(slug) == 26
-
-def test_generate_slug_characters():
-    "generates a base32-encoded slug"
-
-    def is_b32(string):
-        b32_alphabet = "01234556789abcdefghijklmnopqrstuvwxyz"
-        return all(char in b32_alphabet for char in string)
-
-    assert is_b32(slug)
-
-def test_starts_with_empty_strings():
-    "creates an empty strings dict by default"
-    assert strings == {}
+import socket
+from onionshare import OnionShare
+from nose import with_setup
 
 def test_choose_port_returns_a_port_number():
     "choose_port() returns a port number"
-    assert  1024 <= choose_port()  <= 65535
+    app = OnionShare()
+    assert  1024 <= app.port <= 65535
 
 def test_choose_port_returns_an_open_port():
     "choose_port() returns an open port"
-    port = choose_port()
-    socket.socket().bind(("127.0.0.1", port))
-
-def write_tempfile(text):
-    tempdir = tempfile.mkdtemp()
-    path = tempdir + "/test-file.txt"
-    with open(path, "w") as f:
-      f.write(text)
-      f.close()
-    return path
-
-def test_filehash_returns_correct_hash():
-    "file_crunching() returns correct hash"
-
-    text = """
-           If you want a picture of the future, imagine a boot stamping on an
-           encrypted, redundant, distributed filesystem -- forever.
-           """
-    tempfile = write_tempfile(text)
-    filehash, _ = file_crunching(tempfile)
-
-    assert filehash == 'bc004fe72e6530a545570b4c6ce76bcb78ea526b'
-
-def test_filehash_returns_correct_size():
-    "file_crunching() returns correct size"
-
-    text = "AUSCANNZUKUS has always been at war with Eastasia."
-    tempfile = write_tempfile(text)
-    _, filesize = file_crunching(tempfile)
-
-    assert filesize == 50
+    app = OnionShare()
+    # choose a new port
+    app.choose_port()
+    socket.socket().bind(("127.0.0.1", app.port))
diff --git a/test/onionshare_web_test.py b/test/onionshare_web_test.py
new file mode 100644
index 00000000..fc545a14
--- /dev/null
+++ b/test/onionshare_web_test.py
@@ -0,0 +1,17 @@
+from onionshare import web
+from nose import with_setup
+
+def test_generate_slug_length():
+    "generates a 26-character slug"
+    assert len(web.slug) == 26
+
+def test_generate_slug_characters():
+    "generates a base32-encoded slug"
+
+    def is_b32(string):
+        b32_alphabet = "01234556789abcdefghijklmnopqrstuvwxyz"
+        return all(char in b32_alphabet for char in string)
+
+    assert is_b32(web.slug)
+
+
diff --git a/test/test_helpers.py b/test/test_helpers.py
new file mode 100644
index 00000000..ae0f85b0
--- /dev/null
+++ b/test/test_helpers.py
@@ -0,0 +1,21 @@
+import tempfile
+
+class MockSubprocess():
+  def __init__(self):
+      self.last_call = None
+
+  def call(self, args):
+      self.last_call = args
+
+  def last_call_args(self):
+      return self.last_call
+
+def write_tempfile(text):
+    tempdir = tempfile.mkdtemp()
+    path = tempdir + "/test-file.txt"
+    with open(path, "w") as f:
+      f.write(text)
+      f.close()
+    return path
+
+