OpenAI compatible API · Attested · Public status

Z.ai: GLM 5.1 vs zai-org/glm-4.5-air

Z.ai: GLM 5.1 vs zai-org/glm-4.5-air: compare current API pricing, context, provider routes, privacy, p50 latency, and OpenAI-compatible access.

Verify gateway

Onebase URL to migrate

100sof models and routes

0prompt or output logs. Always.

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

Monthly evidence

zai-org/glm-4.5-air has the lower cheapest prompt+completion route on TrustedRouter. Z.ai: GLM 5.1 has more provider fallback routes, while Z.ai: GLM 5.1 has the larger context window. Probe-backed speed data is shown when enough recent samples exist.

$4.2833/1MZ.ai: GLM 5.1 cheapest route

$1.0339/1Mzai-org/glm-4.5-air cheapest route

1081 msZ.ai: GLM 5.1 fastest measured p50 TTFT via digitalocean

not enough datazai-org/glm-4.5-air fastest measured p50 TTFT

Prices and live route measurements can change. Use the monthly reports when you need a stable evidence window, then run a small task-specific eval before choosing a production default.

Z.ai: GLM 5.1zai-org/glm-4.5-air

Model idz-ai/glm-5.1zai-org/glm-4.5-air

Publisher Z.AI Novita AI

AI IQ IQ 114#39 —

Context204,800 tokens131,072 tokens

Provider routes242

Cheapest route$4.2833/1M$1.0339/1M

Privacy posturehas provider E2EE routeprovider posture varies

Fastest measured p50 TTFT1081 ms via digitaloceannot enough data

Highest measured throughputnot enough datanot enough data

Recent route uptime range100.00%100.00%

Modes chat chat

Z.ai: GLM 5.1 routes

Overview24 endpoints
PricingPrompt and completion rates
BenchmarksTrustedRouter and external sources
ProvidersAll serving providers

zai-org/glm-4.5-air routes

Overview2 endpoints
PricingPrompt and completion rates
ProvidersAll serving providers

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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,
)

Questions

Which should I use, Z.ai: GLM 5.1 or zai-org/glm-4.5-air?

Is Z.ai: GLM 5.1 or zai-org/glm-4.5-air cheaper?

The current cheapest TrustedRouter route is $4.2833/1M for Z.ai: GLM 5.1 and $1.0339/1M for zai-org/glm-4.5-air. The comparison uses current catalog prices and updates as provider pricing changes.

Is Z.ai: GLM 5.1 or zai-org/glm-4.5-air faster?

Current measured p50 time to first token is 1081 ms for Z.ai: GLM 5.1 and not enough data for zai-org/glm-4.5-air. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test Z.ai: GLM 5.1 and zai-org/glm-4.5-air with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between z-ai/glm-5.1 and zai-org/glm-4.5-air. This makes side-by-side evals possible without maintaining two provider integrations.