GPT-6 Astra vs Grok 4.6
API pricing, context, and independently measured performance, side by side. Grok 4.6 starts 80% cheaper on input than GPT-6 Astra at list prices.
GPT-6 Astra
OpenAI · released Sep 4, 2026
Best input$10.00 / MTok
Best output$50.00 / MTok
Context1.05M
Providers5
Fastest measured4.3s° TTFT · 187 tok/s
VisionToolsReasoningStructured outputPrompt caching
Grok 4.6
xAI · released Aug 12, 2026
Best input$2.00 / MTok
Best output$6.00 / MTok
Context500K
Providers5
Fastest measured1s TTFT · 9 tok/s
VisionToolsReasoningStructured outputPrompt caching
Cheapest providers, measuredUSD / MTOK
| MODEL | PROVIDER | INPUT | OUTPUT | TTFT | TPS | SMOKE |
|---|---|---|---|---|---|---|
| GPT-6 Astra |  OpenAI | $5.00 | $25.00 | — | — | — |
| GPT-6 Astra |  Azure | $10.00 | $50.00 | 4.3s° | 187° tok/s | — |
| Grok 4.6 |  xAI | $2.00 | $6.00 | 1s | 9 tok/s | — |
| Grok 4.6 |  Amazon Bedrock | $2.20 | $6.60 | — | — | — |
TTFT/TPS: ModelIndex-measured medians (P50, trailing 21d) · chat10k profile (~10K in / 200 out) · ° = measured via OpenRouter routing (adds a hop) · SMOKE: of 5 programmatic capability probes passed · methodology v1.1 — full details on each model page