OpenAI compatible API · Attested · Public status

GPT 5.5 vs Z.ai: GLM 5.2

GPT 5.5 vs Z.ai: GLM 5.2: 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

GPT 5.5 has the larger context window. Z.ai: GLM 5.2 has the lower published input-plus-output rate and more Credits provider routes. There is not enough recent probe data to compare speed.

$36.925/1MGPT 5.5 cheapest route

$2.2999/1MZ.ai: GLM 5.2 cheapest route

not enough dataGPT 5.5 fastest measured p50 TTFT

548 msZ.ai: GLM 5.2 fastest measured p50 TTFT via friendli

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.

GPT 5.5Z.ai: GLM 5.2

Model idopenai/gpt-5.5-2026-04-23z-ai/glm-5.2

Publisher OpenAI Z.AI

AI IQ — IQ 119#39

Context1,050,000 tokens1,048,576 tokens

Credits provider routes127

Cheapest route$36.925/1M$2.2999/1M

Cached inputNot published$0.110775/1M to $0.975875/1M

Privacy postureprovider posture varieshas provider E2EE route

Fastest measured p50 TTFTnot enough data548 ms via friendli

Highest measured throughputnot enough data163 tok/s via parasail

Recent route uptime rangenot enough data50.00% to 100.00%

Modes chat chat

GPT 5.5 routes

Overview1 Credits routes

Z.ai: GLM 5.2 routes

Overview27 Credits routes
PricingInput, cached input, and output rates
BenchmarksTrustedRouter and external sources
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="openai/gpt-5.5-2026-04-23",
    messages=messages,
)

Questions

Which should I use, GPT 5.5 or Z.ai: GLM 5.2?

GPT 5.5 has the larger context window. Z.ai: GLM 5.2 has the lower published input-plus-output rate and more Credits provider routes. There is not enough recent probe data to compare speed.

Is GPT 5.5 or Z.ai: GLM 5.2 cheaper?

The current cheapest TrustedRouter route is $36.925/1M for GPT 5.5 and $2.2999/1M for Z.ai: GLM 5.2. The comparison uses current catalog prices and updates as provider pricing changes.

Is GPT 5.5 or Z.ai: GLM 5.2 faster?

Current measured p50 time to first token is not enough data for GPT 5.5 and 548 ms for Z.ai: GLM 5.2. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test GPT 5.5 and Z.ai: GLM 5.2 with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between openai/gpt-5.5-2026-04-23 and z-ai/glm-5.2. This makes side-by-side evals possible without maintaining two provider integrations.