OpenAI compatible API · Attested · Public status

ByteDance/Seed-1.8 vs Z.ai: GLM 5.1

ByteDance/Seed-1.8 vs Z.ai: GLM 5.1: 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

ByteDance/Seed-1.8 has the lower cheapest prompt+completion route on TrustedRouter. Z.ai: GLM 5.1 has more provider fallback routes, while ByteDance/Seed-1.8 has the larger context window. Probe-backed speed data is shown when enough recent samples exist.

$2.3625/1MByteDance/Seed-1.8 cheapest route

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

not enough dataByteDance/Seed-1.8 fastest measured p50 TTFT

664 msZ.ai: GLM 5.1 fastest measured p50 TTFT via wafer

ByteDance/Seed-1.8Z.ai: GLM 5.1

Model idbytedance/seed-1.8z-ai/glm-5.1

Publisher DeepInfra Z.AI

AI IQ — IQ 114#32

Context256,000 tokens204,800 tokens

Provider routes224

Cheapest route$2.3625/1M$4.263/1M

Privacy postureprovider posture varieshas confidential-compute route

Fastest measured p50 TTFTnot enough data664 ms via wafer

Highest measured throughputnot enough datanot enough data

Recent route uptime rangenot enough data75.00% to 100.00%

Modes chat chat

ByteDance/Seed-1.8 routes

Overview2 endpoints
PricingPrompt and completion rates
ProvidersAll serving providers

Z.ai: GLM 5.1 routes

Overview24 endpoints
PricingPrompt and completion 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="bytedance/seed-1.8",
    messages=messages,
)

Questions

Which should I use, ByteDance/Seed-1.8 or Z.ai: GLM 5.1?

Is ByteDance/Seed-1.8 or Z.ai: GLM 5.1 cheaper?

The current cheapest TrustedRouter route is $2.3625/1M for ByteDance/Seed-1.8 and $4.263/1M for Z.ai: GLM 5.1. The comparison uses current catalog prices and updates as provider pricing changes.

Is ByteDance/Seed-1.8 or Z.ai: GLM 5.1 faster?

Current measured p50 time to first token is not enough data for ByteDance/Seed-1.8 and 664 ms for Z.ai: GLM 5.1. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test ByteDance/Seed-1.8 and Z.ai: GLM 5.1 with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between bytedance/seed-1.8 and z-ai/glm-5.1. This makes side-by-side evals possible without maintaining two provider integrations.