GPT-5.1 Medium vs Kimi K2-Thinking-0905: Specs & Benchmark Comparison
| Characteristic | GPT-5.1 Medium | Kimi K2-Thinking-0905 |
|---|---|---|
| Company | OpenAI | Moonshot AI |
| Release Date | November 11, 2025 | September 4, 2025 |
| Parameters | — | 1.0T |
| Multimodal | Yes | No |
| Context (input) | 256K | 262K |
| Context (output) | 64K | 66K |
| Input Price / 1M | $1.00 | $0.60 |
| Output Price / 1M | $4.00 | $2.40 |
| Average Score | 1.0 | 0.9 |
| Benchmarks | ||
| AIME 2025 | 1.0 | 1.0 |
Visual Benchmark Comparison
GPT-5.1 Medium
Kimi K2-Thinking-0905
AIME 20251.0 vs 1.0
1.0
1.0
Verdict
Kimi K2-Thinking-0905 leads in 2 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: GPT-5.1 Medium — 1.0, Kimi K2-Thinking-0905 — 0.9.
API Cost
Kimi K2-Thinking-0905 is 1.7x cheaper: input $0.60/1M vs $1.00/1M tokens.
Context Window
Kimi K2-Thinking-0905 supports a larger context: 262K vs 256K tokens.
Recency
GPT-5.1 Medium is newer: released 11/11/2025 vs 9/4/2025.
More About These Models
Related Comparisons
The GPT-5.1 Medium and Kimi K2-Thinking-0905 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.1 Medium or Kimi K2-Thinking-0905 page. See also the complete list of AI model comparisons.