GPT-6 Astra vs Kimi K3.1 Pro
| Spec | GPT-6 Astra | Kimi K3.1 Pro |
|---|---|---|
| Respan Index | 72.1 (#3) | 71.2 (#5) |
| Blended price per 1M | $10 | $3.6 |
| Context window | 1.1M | 1.0M |
| Input / output per 1M | $5 / $25 | $1.8 / $9 |
| Max output | 128K | 1.0M |
| Input | text, vision | text, vision, video |
| Released | 2026-09-03 | 2026-10-23 |
Respan Index by category
Each category is scored 0 to 100, and how far ahead the winner is. Leads under a point are close to even.
| Category | GPT-6 Astra | Kimi K3.1 Pro |
|---|---|---|
| Coding | 58.4 GPT-6 Astra | 67.7 Kimi K3.1 Pro |
| Agents | 77.7 GPT-6 Astra | 69.7 Kimi K3.1 Pro |
| Reasoning | 85.8 GPT-6 Astra | 83.7* Kimi K3.1 Pro |
| Knowledge & language | 75.6 GPT-6 Astra | 71.5* Kimi K3.1 Pro |
| Human preference | 60.3 GPT-6 Astra | 58.5 Kimi K3.1 Pro |
* Estimated: no published scores in that category. How the Respan Index works
Benchmarks both report
GPT-6 Astra leads on 2 of the 3 benchmarks both report. Higher is better. Each score links to where it was published.
| Benchmark | GPT-6 Astra | Kimi K3.1 Pro |
|---|---|---|
| LMArena Agent (LMArena) | 0.1296 | 0.0596 |
| LMArena WebDev (LMArena) | 1773 | 1695 |
| Terminal-Bench 4.0 (Vals AI) | 59.6% | 63.6% |
FAQ
Is GPT-6 Astra better than Kimi K3.1 Pro?
GPT-6 Astra scores 72.1 on the Respan Index (#3), ahead of Kimi K3.1 Pro at 71.2 (#5). GPT-6 Astra leads on 2 of the 3 benchmarks both report.
Which is cheaper, GPT-6 Astra or Kimi K3.1 Pro?
GPT-6 Astra lists at $5 input and $25 output per 1M tokens; Kimi K3.1 Pro at $1.8 and $9. Kimi K3.1 Pro is 2.8x cheaper per token at list price.
Which has the larger context window?
GPT-6 Astra accepts 1.1M tokens and Kimi K3.1 Pro 1.0M tokens.