| Signal | GPT-5.1-Codex | Delta | Kimi K2 Thinking |
|---|---|---|---|
Capabilities | 83 | +17 | |
Pricing | 10 | +8 | |
Context window size | 89 | +8 | |
Recency | 100 | -- | |
Output Capacity | 85 | +65 | |
| Overall Result | 4 wins | of 5 | 0 wins |
8
days higher
6
days
16
days higher
OpenAI
Moonshot AI
Kimi K2 Thinking saves you $478.00/month
That's $5736.00/year compared to GPT-5.1-Codex at your current usage level of 100K calls/month.
| Metric | GPT-5.1-Codex | Kimi K2 Thinking | Winner |
|---|---|---|---|
| Overall Score | 40 | 40 | -- |
| Rank | #174 | #176 | GPT-5.1-Codex |
| Quality Rank | #174 | #176 | GPT-5.1-Codex |
| Adoption Rank | #174 | #176 | GPT-5.1-Codex |
| Parameters | -- | -- | -- |
| Context Window | 400K | 131K | GPT-5.1-Codex |
| Pricing | $1.25/$10.00/M | $0.47/$2.00/M | -- |
| Signal Scores | |||
| Capabilities | 83 | 67 | GPT-5.1-Codex |
| Pricing | 10 | 2 | GPT-5.1-Codex |
| Context window size | 89 | 81 | GPT-5.1-Codex |
| Recency | 100 | 100 | GPT-5.1-Codex |
| Output Capacity | 85 | 20 | GPT-5.1-Codex |
Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Here's what the scores mean for these two models:
Scores 40/100 (rank #174), placing it in the top 40% of all 290 models tracked.
Scores 40/100 (rank #176), placing it in the top 40% of all 290 models tracked.
With only a 0-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.
Kimi K2 Thinking offers 78% better value per quality point. At 1M tokens/day, you'd spend $37.05/month with Kimi K2 Thinking vs $168.75/month with GPT-5.1-Codex - a $131.70 monthly difference.
Both models have comparable response speeds. For most applications, the latency difference is negligible.
When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.
Code generation & review
Higher benchmark score (0/100) indicates stronger performance on coding tasks like generating functions, debugging, and refactoring
Customer support chatbot
Faster response time (speed score 0/100) is critical for user-facing chat. Kimi K2 Thinking also offers lower per-token costs for high-volume support
Long document analysis
Larger context window (400K tokens) can process longer documents, contracts, and research papers in a single pass
Batch data extraction
Lower output pricing ($2.00/M) reduces costs when processing thousands of records daily
Creative writing & content
Higher overall composite score (40/100) correlates with better nuance, coherence, and style in long-form content
Image understanding & OCR
Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly
GPT-5.1-Codex and Kimi K2 Thinking are extremely close in overall performance (only 0 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.
Best for Quality
GPT-5.1-Codex
Marginally better benchmark scores; both are excellent
Best for Cost
Kimi K2 Thinking
78% lower pricing; better value at scale
Best for Reliability
GPT-5.1-Codex
Higher uptime and faster response speeds
Best for Prototyping
GPT-5.1-Codex
Stronger community support and better developer experience
Best for Production
GPT-5.1-Codex
Wider enterprise adoption and proven at scale
by OpenAI
| Capability | GPT-5.1-Codex | Kimi K2 Thinking |
|---|---|---|
| Vision (Image Input)differs | ||
| Function Calling | ||
| Streaming | ||
| JSON Mode | ||
| Reasoning | ||
| Web Search | ||
| Image Output |
OpenAI
Moonshot AI
Kimi K2 Thinking saves you $11.00/month
That's 77% cheaper than GPT-5.1-Codex at 1,000 tokens/request and 100 requests/day.
Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.
| Parameter | GPT-5.1-Codex | Kimi K2 Thinking |
|---|---|---|
| Context Window | 400K | 131K |
| Max Output Tokens | 128,000 | -- |
| Open Source | No | Yes |
| Created | Nov 13, 2025 | Nov 6, 2025 |
Both GPT-5.1-Codex and Kimi K2 Thinking score 40/100, making them extremely close competitors. Choose based on pricing, provider ecosystem, or specific capability requirements.
GPT-5.1-Codex is ranked #174 and Kimi K2 Thinking is ranked #176 out of 290+ AI models. Rankings use a composite score combining benchmark performance (90%) from MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations, with capabilities and context window as tiebreakers (10%). Scores update hourly.
Kimi K2 Thinking is cheaper at $2.00/M output tokens vs GPT-5.1-Codex's $10.00/M output tokens - 5.0x more expensive. Input token pricing: GPT-5.1-Codex at $1.25/M vs Kimi K2 Thinking at $0.47/M.
GPT-5.1-Codex has a larger context window of 400,000 tokens compared to Kimi K2 Thinking's 131,072 tokens. A larger context window means the model can process longer documents and conversations.