GPT-6 Astra vs Grok 4.5
API pricing, context window and capabilities for GPT-6 Astra and Grok 4.5, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.
Verdict
computed from the published numbersGPT-6 Astra wins on Terminal-Bench, on intelligence and on context window. Grok 4.5 wins on price.
Price
Grok 4.5
Terminal-Bench
GPT-6 Astra
Intelligence
GPT-6 Astra
Context window
GPT-6 Astra
Key takeaways
who wins on what, from the published numbersGPT-6 Astra wins
- Larger context window (1.1M vs 500K)
- More serving providers (5 vs 3)
Grok 4.5 wins
- Cheaper input ($10.00 vs $2.00 /1M)
- Cheaper output ($50.00 vs $6.00 /1M)
- Higher max output (128K vs 500K)
Cheaper overall
Grok 4.5
$2.00 + $6.00 /1M
Larger context
GPT-6 Astra
1.1M
More providers
GPT-6 Astra
5 providers
Pricing & specs
cheapest listed route · per 1M tokensOn-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
| GPT-6 Astra | Grok 4.5 | |
|---|---|---|
| Input $/1M | $10.00via OpenAI | $2.00via xAI best |
| Output $/1M | $50.00via OpenAI | $6.00via xAI best |
| Context window | 1.1M best | 500K |
| Max output | 128K | 500K best |
| Serving providers | 5 best | 3 |
| Date | Released Sep 4, 2026 | Released Jul 7, 2026 |
Benchmarks
Benchmark scores, side by side| GPT-6 Astra | Grok 4.5 | |
|---|---|---|
| Intelligence | 52.7 best | 38.8 |
| Terminal-Bench | 88% best | 82% |
| GPQA Diamond | 96% best | 93% |
| Output speed | 61 t/s | 63 t/s best |
| Latency (TTFT) | 280.05s | 13.52s best |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
GPT-6 Astra
via OpenAI
$100
Grok 4.5
via OpenRouter
$16
Capabilities
feature support, side by side| Feature | GPT-6 Astra | Grok 4.5 |
|---|---|---|
| Vision | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | — | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | ✓ | ✓ |
Related comparisons
Frequently asked questions
Which is cheaper, GPT-6 Astra or Grok 4.5?
Grok 4.5 is cheaper for input ($10.00 vs $2.00 per 1M tokens) from xAI. Grok 4.5 is cheaper for output ($50.00 vs $6.00 per 1M tokens) from xAI.
What is the context window difference between GPT-6 Astra and Grok 4.5?
GPT-6 Astra has a 1.1M-token context window and Grok 4.5 has 500K tokens, so GPT-6 Astra can take a larger prompt.
How do GPT-6 Astra and Grok 4.5 compare on benchmarks?
On the tracked benchmarks, GPT-6 Astra leads on Terminal-Bench, and GPT-6 Astra leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026
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