OpenAI: GPT-5.4 Nano vs MoonshotAI: Kimi K2.5
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-11-07.
| OpenAI: GPT-5.4 Nano | MoonshotAI: Kimi K2.5 | |
|---|---|---|
| Vendor | openai | moonshotai |
| Quality Score | 100 | 100 |
| Benchmark Score | 68.1 | 64.3 |
| Input Price | $0.20/M | $0.53/M |
| Output Price | $1.25/M | $3.33/M |
| Context Window | 400,000 | 262,144 |
| Max Output | 128,000 | 65,536 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 63.1 | 62.9 |
| ai_index_agentic | 45.4 | - |
| ai_index_coding | 92.5 | - |
| eqbench | - | 55.2 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, GPT-5.4 Nano costs $0.51 and Kimi K2.5 costs $1.36, so GPT-5.4 Nano is about 2.7 times cheaper for the same work.
GPT-5.4 Nano reads up to 400,000 tokens at once, roughly 600 pages of text, against about 393 pages for Kimi K2.5.
On our blended benchmark score GPT-5.4 Nano leads 68.1 to 64.3.
Across the 20 tasks where they differ, GPT-5.4 Nano scores higher on 20 (SQL Generation, Code Review, Code Completion and others).
GPT-5.4 Nano was released in March 2026 and Kimi K2.5 in January 2026.
Pick GPT-5.4 Nano if you need lower cost, long documents, benchmark performance or the stronger all-round task scores.
Costs use current list prices per million tokens; page counts assume about 0.75 words per token and 500 words per page.
Who wins by task?
| Task | OpenAI: GPT-5.4 Nano | MoonshotAI: Kimi K2.5 |
|---|---|---|
| SQL Generation | 163 | 142 |
| Code Review | 158 | 145 |
| Code Completion | 133 | 131 |
| Code Refactoring | 157 | 145 |
| Bug Fixing | 168 | 149 |
| Unit Test Generation | 148 | 132 |
| Code Documentation | 140 | 135 |
| Regex Writing | 132 | 127 |
| CI/CD Pipelines | 139 | 128 |
| Frontend Component Design | 141 | 131 |
| Data Analysis | 159 | 136 |
| CSV / Spreadsheet Cleanup | 151 | 133 |
| ETL Scripting | 148 | 136 |
| JSON Extraction | 146 | 131 |
| Bulk Data Labeling | 134 | 128 |
| OCR / Document Parsing | 144 | 133 |
| Table Extraction from PDFs | 144 | 133 |
| Long-Document Summarization | 154 | 146 |
| Short-Form Summarization | 130 | 127 |
| Blog Post Writing | 135 | 130 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →