diff --git a/tests/device/test_largeblobs.py b/tests/device/test_largeblobs.py
new file mode 100644
index 0000000..c84d959
--- /dev/null
+++ b/tests/device/test_largeblobs.py
@@ -0,0 +1,137 @@
+from fido2.ctap import CtapError
+from fido2.ctap2.pin import ClientPin, PinProtocolV1, PinProtocolV2
+from fido2.ctap2.blob import LargeBlobs
+from fido2.server import Fido2Server
+from fido2.utils import websafe_encode, websafe_decode
+from . import TEST_PIN
+
+import os
+import pytest
+
+
+@pytest.fixture(autouse=True, scope="module")
+def preconditions(dev_manager):
+    if not LargeBlobs.is_supported(dev_manager.info):
+        pytest.skip("LargeBlobs not supported by authenticator")
+
+
+@pytest.fixture(params=[PinProtocolV1, PinProtocolV2])
+def pin_protocol(request, info):
+    proto = request.param
+    if proto.VERSION not in info.pin_uv_protocols:
+        pytest.skip(f"PIN/UV protocol {proto.VERSION} not supported")
+
+    return proto()
+
+
+def get_lb(ctap2, pin_protocol, permissions=ClientPin.PERMISSION.LARGE_BLOB_WRITE):
+    token = ClientPin(ctap2, pin_protocol).get_pin_token(TEST_PIN, permissions)
+    return LargeBlobs(ctap2, pin_protocol, token)
+
+
+def test_read_write(ctap2, pin_protocol):
+    lb = get_lb(ctap2, pin_protocol)
+    assert len(lb.read_blob_array()) == 0
+
+    key1 = os.urandom(32)
+    data1 = b"test data"
+    key2 = os.urandom(32)
+    data2 = b"some other data"
+
+    assert lb.get_blob(key1) is None
+    lb.put_blob(key1, data1)
+    assert lb.get_blob(key1) == data1
+    assert len(lb.read_blob_array()) == 1
+
+    lb.put_blob(key2, data2)
+    assert lb.get_blob(key1) == data1
+    assert lb.get_blob(key2) == data2
+    assert len(lb.read_blob_array()) == 2
+
+    lb.delete_blob(key1)
+    assert lb.get_blob(key1) is None
+    assert lb.get_blob(key2) == data2
+    assert len(lb.read_blob_array()) == 1
+
+    lb.delete_blob(key2)
+    assert lb.get_blob(key2) is None
+    assert len(lb.read_blob_array()) == 0
+
+
+def test_missing_permissions(ctap2, pin_protocol):
+    key = os.urandom(32)
+    data = b"test data"
+
+    # Try write without PIN token
+    lb = LargeBlobs(ctap2, pin_protocol)
+    blobs = lb.read_blob_array()
+    assert len(blobs) == 0
+
+    with pytest.raises(CtapError, match="PUAT_REQUIRED"):
+        lb.put_blob(key, data)
+
+    # Try with wrong permissions
+    lb = get_lb(ctap2, pin_protocol, ClientPin.PERMISSION.CREDENTIAL_MGMT)
+    with pytest.raises(CtapError, match="PIN_AUTH_INVALID"):
+        lb.put_blob(key, data)
+
+
+def test_large_blob_key(client, ctap2, pin_protocol):
+    rp = {"id": "example.com", "name": "Example RP"}
+    server = Fido2Server(rp)
+    user = {"id": b"user_id", "name": "A. User"}
+
+    create_options, state = server.register_begin(
+        user,
+        resident_key_requirement="required",
+        user_verification="required",
+    )
+
+    # Create a credential
+    result = client.make_credential(
+        {
+            **create_options["publicKey"],
+            "extensions": {"largeBlob": {"support": "required"}},
+        }
+    )
+    auth_data = server.register_complete(state, result)
+    credentials = [auth_data.credential_data]
+
+    assert result.client_extension_results.large_blob.supported is True
+    assert result.client_extension_results["largeBlob"]["supported"] is True
+
+    request_options, state = server.authenticate_begin(
+        credentials, user_verification="required"
+    )
+
+    data = b"test data"
+
+    selection = client.get_assertion(
+        {
+            **request_options["publicKey"],
+            # Write a large blob
+            "extensions": {"largeBlob": {"write": websafe_encode(data)}},
+        }
+    )
+    result = selection.get_response(0)
+
+    assert result.client_extension_results.large_blob.written is True
+    assert result.client_extension_results["largeBlob"]["written"] is True
+
+    # Authenticate the credential
+    selection = client.get_assertion(
+        {
+            **request_options["publicKey"],
+            # Read back the blob
+            "extensions": {"largeBlob": {"read": True}},
+        }
+    )
+    result = selection.get_response(0)
+
+    assert result.client_extension_results.large_blob.blob == data
+    assert websafe_decode(result.client_extension_results["largeBlob"]["blob"]) == data
+
+    # Clear the data
+    lb = get_lb(ctap2, pin_protocol)
+    lb.write_blob_array([])
+    assert len(lb.read_blob_array()) == 0