diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index 75f4c521629..c20e6346633 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -44332,6 +44332,21 @@
         "supports_tool_choice": true,
         "source": "https://docs.z.ai/guides/overview/pricing"
     },
+    "zai/glm-5.3": {
+        "cache_creation_input_token_cost": 0,
+        "cache_read_input_token_cost": 2.6e-07,
+        "input_cost_per_token": 1.4e-06,
+        "litellm_provider": "zai",
+        "max_input_tokens": 1000000,
+        "max_output_tokens": 128000,
+        "mode": "chat",
+        "output_cost_per_token": 4.4e-06,
+        "source": "https://docs.z.ai/guides/overview/pricing",
+        "supports_function_calling": true,
+        "supports_prompt_caching": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": true
+    },
     "zai/glm-5.1": {
         "cache_creation_input_token_cost": 0,
         "cache_read_input_token_cost": 2.6e-07,
diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index 75f4c521629..c20e6346633 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -44332,6 +44332,21 @@
         "supports_tool_choice": true,
         "source": "https://docs.z.ai/guides/overview/pricing"
     },
+    "zai/glm-5.3": {
+        "cache_creation_input_token_cost": 0,
+        "cache_read_input_token_cost": 2.6e-07,
+        "input_cost_per_token": 1.4e-06,
+        "litellm_provider": "zai",
+        "max_input_tokens": 1000000,
+        "max_output_tokens": 128000,
+        "mode": "chat",
+        "output_cost_per_token": 4.4e-06,
+        "source": "https://docs.z.ai/guides/overview/pricing",
+        "supports_function_calling": true,
+        "supports_prompt_caching": true,
+        "supports_reasoning": true,
+        "supports_tool_choice": true
+    },
     "zai/glm-5.1": {
         "cache_creation_input_token_cost": 0,
         "cache_read_input_token_cost": 2.6e-07,
diff --git a/tests/test_litellm/llms/zai/test_zai_provider.py b/tests/test_litellm/llms/zai/test_zai_provider.py
index 38ddac8d510..ad87a65a740 100644
--- a/tests/test_litellm/llms/zai/test_zai_provider.py
+++ b/tests/test_litellm/llms/zai/test_zai_provider.py
@@ -128,6 +128,36 @@ def test_glm47_cost_calculation(local_model_cost_map):
     assert math.isclose(completion_cost, 2.2, rel_tol=1e-6)
 
 
+def test_glm53_context_and_capabilities(local_model_cost_map):
+    """GLM-5.3 ships a 1M context with 128K max output, text in, reasoning always on"""
+
+    info = litellm.model_cost["zai/glm-5.3"]
+
+    assert info["max_input_tokens"] == 1000000
+    assert info["max_output_tokens"] == 128000
+    assert info["supports_reasoning"] is True
+    assert info["supports_prompt_caching"] is True
+    assert info.get("supports_vision") is not True
+
+
+def test_glm53_cost_calculation(local_model_cost_map):
+    """GLM-5.3 bills $1.4/M input, $4.4/M output, $0.26/M on a cache hit"""
+
+    prompt_cost, completion_cost = cost_per_token(
+        model="zai/glm-5.3",
+        prompt_tokens=1000000,
+        completion_tokens=1000000,
+    )
+
+    assert math.isclose(prompt_cost, 1.4, rel_tol=1e-6)
+    assert math.isclose(completion_cost, 4.4, rel_tol=1e-6)
+    assert math.isclose(
+        litellm.model_cost["zai/glm-5.3"]["cache_read_input_token_cost"] * 1000000,
+        0.26,
+        rel_tol=1e-6,
+    )
+
+
 @pytest.mark.asyncio
 async def test_zai_completion_call(respx_mock, zai_response, monkeypatch):
     """Test completion call with zai provider using mocked response"""