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SpaceXAI: Grok 4.20 vs Z.ai: GLM 5.3 Flash

Try both on us. Starter credit covers your first requests, then one key routes Grok 4.20 and GLM 5.3 Flash. 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

SpaceXAI: Grok 4.20 has the larger context window. Z.ai: GLM 5.3 Flash has the lower published input-plus-output rate and more Credits provider routes. There is not enough recent probe data to compare speed.

$3.95625/1MSpaceXAI: Grok 4.20 cheapest route

$0.32705/1MZ.ai: GLM 5.3 Flash cheapest route

not enough dataSpaceXAI: Grok 4.20 fastest measured p50 TTFT

1213 msZ.ai: GLM 5.3 Flash fastest measured p50 TTFT via makora

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.

SpaceXAI: Grok 4.20Z.ai: GLM 5.3 Flash

Model idx-ai/grok-4.20z-ai/glm-5.3-flash

Publisher xAI Grok Z.AI

AI IQ IQ 111#72 IQ 119#47

Context2,000,000 tokens1,048,576 tokens

Credits provider routes132

Cheapest route$3.95625/1M$0.32705/1M

Cached input$0.211/1M to $0.422/1M$0.015825/1M to $0.068575/1M

Privacy postureprovider posture varieshas Confidential route (E2EE + ZDR)

Fastest measured p50 TTFTnot enough data1213 ms via makora

Highest measured throughputnot enough datanot enough data

Recent route uptime range100.00%75.00% to 100.00%

Modes chat chat

SpaceXAI: Grok 4.20 routes

Overview1 Credits routes

Z.ai: GLM 5.3 Flash routes

Overview32 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="x-ai/grok-4.20",
    messages=messages,
)

Questions

Which should I use, SpaceXAI: Grok 4.20 or Z.ai: GLM 5.3 Flash?

Is SpaceXAI: Grok 4.20 or Z.ai: GLM 5.3 Flash cheaper?

The current cheapest TrustedRouter route is $3.95625/1M for SpaceXAI: Grok 4.20 and $0.32705/1M for Z.ai: GLM 5.3 Flash. The comparison uses current catalog prices and updates as provider pricing changes.

Is SpaceXAI: Grok 4.20 or Z.ai: GLM 5.3 Flash faster?

Current measured p50 time to first token is not enough data for SpaceXAI: Grok 4.20 and 1213 ms for Z.ai: GLM 5.3 Flash. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test SpaceXAI: Grok 4.20 and Z.ai: GLM 5.3 Flash with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between x-ai/grok-4.20 and z-ai/glm-5.3-flash. This makes side-by-side evals possible without maintaining two provider integrations.