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OpenAI GPT OSS vs Z.ai: GLM 5.3

Try both on us. Starter credit covers your first requests, then one key routes OpenAI GPT OSS and GLM 5.3. Switch by changing the model name.

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

OpenAI GPT OSS has the lower published input-plus-output rate. Z.ai: GLM 5.3 has more Credits provider routes, the larger context window and the lower measured p50 time to first token.

$1.1605/1MOpenAI GPT OSS cheapest route

$3.458818/1MZ.ai: GLM 5.3 cheapest route

1232 msOpenAI GPT OSS fastest measured p50 TTFT via cerebras

673 msZ.ai: GLM 5.3 fastest measured p50 TTFT via wafer

The price comparison adds each route's rate for one million input tokens and one million output tokens; your cost depends on your input/output mix. 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.

OpenAI GPT OSSZ.ai: GLM 5.3

Model idcerebras/gpt-oss-120bz-ai/glm-5.3

PublisherNot stated Z.AI

AI IQ IQ 98#132 IQ 124#28

Context131,072 tokens1,048,576 tokens

Credits provider routes133

Cheapest route$1.1605/1M$3.458818/1M

Cached inputNot published$0.1055/1M to $0.84189/1M

Privacy posturehas ZDR routehas Confidential route (E2EE + ZDR)

Fastest measured p50 TTFT1232 ms via cerebras673 ms via wafer

Highest measured throughputnot enough data196 tok/s via thinkingmachines

Recent route uptime range100.00%85.71% to 100.00%

Modes chat chat

OpenAI GPT OSS routes

Overview1 Credits routes

Z.ai: GLM 5.3 routes

Overview33 Credits routes
PricingInput, cached input, and output 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="cerebras/gpt-oss-120b",
    messages=messages,
)

Questions

Which should I use, OpenAI GPT OSS or Z.ai: GLM 5.3?

OpenAI GPT OSS has the lower published input-plus-output rate. Z.ai: GLM 5.3 has more Credits provider routes, the larger context window and the lower measured p50 time to first token.

Is OpenAI GPT OSS or Z.ai: GLM 5.3 cheaper?

The current cheapest TrustedRouter route is $1.1605/1M for OpenAI GPT OSS and $3.458818/1M for Z.ai: GLM 5.3. The comparison uses current catalog prices and updates as provider pricing changes.

Is OpenAI GPT OSS or Z.ai: GLM 5.3 faster?

Current measured p50 time to first token is 1232 ms for OpenAI GPT OSS and 673 ms for Z.ai: GLM 5.3. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test OpenAI GPT OSS and Z.ai: GLM 5.3 with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between cerebras/gpt-oss-120b and z-ai/glm-5.3. This makes side-by-side evals possible without maintaining two provider integrations.