OpenAI compatible API · Attested · Public status

Z.ai: GLM 5.1 vs GLM 5.2 Fast on Fireworks

Compare Z.ai: GLM 5.1 and GLM 5.2 Fast on Fireworks by providers, context, price, and TrustedRouter route support.

Verify gateway

Onebase URL to migrate

100sof models and routes

Noneprompt logs by default

Compare routesProviders, price, context, and policy posture in one view.

Use auto when uptime mattersKeep a primary model and let fallback handle provider failures.

Same API shapeUse the OpenAI client and set the model you want.

Practical read

Z.ai: GLM 5.1 has the lower cheapest prompt+completion route on TrustedRouter. Z.ai: GLM 5.1 has more provider fallback routes, while GLM 5.2 Fast on Fireworks has the larger context window. Current TrustedRouter probes show Z.ai: GLM 5.1 with the lower p50 TTFT.

$4.263/1MZ.ai: GLM 5.1 cheapest route

$12.18/1MGLM 5.2 Fast on Fireworks cheapest route

2807 msZ.ai: GLM 5.1 measured p50 TTFT

3316 msGLM 5.2 Fast on Fireworks measured p50 TTFT

Z.ai: GLM 5.1GLM 5.2 Fast on Fireworks

Model idz-ai/glm-5.1z-ai/glm-5.2-fast

PublisherZ.AIZ.AI

AI IQ IQ 113#30 —

Context204,800 tokens1,048,576 tokens

Provider routes254

Cheapest route$4.263/1M$12.18/1M

Privacy posturehas provider E2EE routeprovider posture varies

Modes chat chat

Z.ai: GLM 5.1 routes

Overview25 endpoints
PricingPrompt and completion rates
BenchmarksTrustedRouter and external sources
ProvidersAll serving providers

GLM 5.2 Fast on Fireworks routes

Overview4 endpoints
PricingPrompt and completion rates
ProvidersAll serving providers

Production choice

Pick a default model. Keep fallback enabled.

TrustedRouter is useful when you know the model you want, but still need provider rollover, budget limits, usage records, and a prompt path you can verify.

OpenAI clientPython

client = OpenAI(
    base_url="https://api.trustedrouter.com/v1",
    api_key="sk-tr-v1-..."
)

response = client.chat.completions.create(
    model="z-ai/glm-5.1",
    messages=messages,
)