GPT-5 vs Kimi K2 Thinking
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
OpenAI · Aug 2025
OpenAI's August 2025 unified flagship that merged the GPT and o-series reasoning lines into one model with selectable effort.
Moonshot AI · Nov 2025
A trillion-parameter open reasoning agent that can chain 200–300 tool calls — the open-weights agentic standout of late 2025.
The verdict
GPT-5 wins 5 of the 6 benchmarks these models share, against 1 for Kimi K2 Thinking. On price the gap is dramatic: Kimi K2 Thinking works out roughly 3.2x cheaper per blended million tokens. GPT-5 also takes 400K of context versus 262K for Kimi K2 Thinking. And Kimi K2 Thinking is open-weights (Modified MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Benchmark head-to-head 5–1
Specs & pricing
| GPT-5 | Kimi K2 Thinking | |
|---|---|---|
| modhub Index | 70.7 | 67.6 |
| Input price / 1M | $1.25 | $0.6 |
| Output price / 1M | $10 | $2.5 |
| Context window | 400K | 262K |
| Max output | 128K | — |
| Open weights | no | yes (Modified MIT) |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text |
| Knowledge cutoff | Sep 2024 | Apr 2025 |
| Released | Aug 2025 | Nov 2025 |
| Example monthly cost* | $27.50 | $9.75 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GPT-5 or Kimi K2 Thinking?
- GPT-5 wins 5 of the 6 benchmarks these models share, against 1 for Kimi K2 Thinking. On price the gap is dramatic: Kimi K2 Thinking works out roughly 3.2x cheaper per blended million tokens. GPT-5 also takes 400K of context versus 262K for Kimi K2 Thinking. And Kimi K2 Thinking is open-weights (Modified MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, GPT-5 or Kimi K2 Thinking?
- GPT-5 costs $1.25/$10 per million input/output tokens, while Kimi K2 Thinking costs $0.6/$2.5. For a typical workload of 10M input and 1.5M output tokens per month, that's $27.50 versus $9.75.
- Which model is better for coding, GPT-5 or Kimi K2 Thinking?
- On SWE-bench Verified — the standard agentic-coding benchmark — GPT-5 scores 74.9% versus 71.3% for Kimi K2 Thinking, making GPT-5 the stronger pick for coding agents.