diff --git a/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3-flash.toml b/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3-flash.toml
index 7e8d208090a..8a1203370b8 100644
--- a/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3-flash.toml
+++ b/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3-flash.toml
@@ -1,14 +1,17 @@
 # Pricing: https://fireworks.ai/models/fireworks/glm-5p3-flash (accessed 2026-09-02)
 # Released on Fireworks Serverless API 2026-08-26.
-# Thinking-only model: reasoning cannot be disabled. Use the same two effective
-# tiers as Fireworks GLM 5.3: low/medium collapse to high; max/xhigh select max.
-# https://docs.fireworks.ai/api-reference/post-chatcompletions (accessed 2026-08-29)
+# Thinking-only model: reasoning cannot be disabled. Three distinct effort
+# tiers like Fireworks GLM 5.3 (NOT the two-tier GLM 5.2 collapse): verified
+# empirically 2026-09-04 — same prompt yields ~9/17/559 reasoning tokens for
+# low/high/max. max/xhigh select max.
+# https://docs.fireworks.ai/api-reference/post-chatcompletions
 base_model = "zhipuai/glm-5.3-flash"
 name = "GLM 5.3 Flash"
+last_updated = "2026-09-04"
 
 [[reasoning_options]]
 type = "effort"
-values = ["high", "max"]
+values = ["low", "high", "max"]
 
 [interleaved]
 field = "reasoning_content"
diff --git a/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3.toml b/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3.toml
index 8fb8037dd97..fa2c2de0072 100644
--- a/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3.toml
+++ b/providers/fireworks-ai/models/accounts/fireworks/models/glm-5p3.toml
@@ -1,16 +1,18 @@
 # Pricing: https://docs.fireworks.ai/serverless/pricing (accessed 2026-08-29)
 # Released on Fireworks Serverless API 2026-08-28.
 # Thinking-only model: reasoning cannot be disabled (reasoning_effort="none"
-# and thinking.type="disabled" both return 400). Two effective tiers like
-# GLM 5.2: low/medium collapse to high, max/xhigh select max.
-# https://docs.fireworks.ai/api-reference/post-chatcompletions (accessed 2026-08-29)
+# and thinking.type="disabled" both return 400). Unlike GLM 5.2 (two tiers,
+# low/medium collapse to high), GLM 5.3 has three distinct effort tiers:
+# verified empirically 2026-09-04 — same prompt yields ~10/25/198 reasoning
+# tokens for low/high/max. max/xhigh select max.
+# https://docs.fireworks.ai/api-reference/post-chatcompletions
 base_model = "zhipuai/glm-5.3"
 name = "GLM 5.3"
-last_updated = "2026-08-28"
+last_updated = "2026-09-04"
 
 [[reasoning_options]]
 type = "effort"
-values = ["high", "max"]
+values = ["low", "high", "max"]
 
 [interleaved]
 field = "reasoning_content"