# GPT-5.3 Codex vs Kimi K2

> Side-by-side benchmark comparison for GPT-5.3 Codex and Kimi K2 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-3-codex-vs-kimi-k2
- Last updated: October 17, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-5.3 Codex and Kimi K2 share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Kimi K2 has the lower published output-token price.
- GPT-5.3 Codex has the larger published context window at 400K.

## Model Snapshot

| Property | GPT-5.3 Codex | Kimi K2 |
|----------|----------|----------|
| Creator | OpenAI | Moonshot AI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Non-Reasoning |
| Context | 400K | 128K |
| Independent public score (not head-to-head) | 60.48 | 33.48 |
| Benchmarks Covered | 11 | 13 |
| Pricing (input/output) | $1.75 / $14.00 | $0.60 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 55.5 (Estimated · #41/128)
- Kimi K2 public-lane score: Coming soon

| Benchmark | GPT-5.3 Codex | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| OSWorld-Verified | 64.7% | Coming soon | Coming soon |
| Gert Labs | 57.47% | Coming soon | Coming soon |
| JobBench | 33.7% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 53.5 (Supported · #35/150)
- Kimi K2 public-lane score: Coming soon

| Benchmark | GPT-5.3 Codex | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85% | 65.8% | GPT-5.3 Codex |
| SWE-bench Pro | 56.8% | Coming soon | Coming soon |
| SWE-Rebench | 58.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| Vibe Code Bench | 61.77% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.3% | Coming soon | Coming soon |
| SWE-bench (Vals) | 78.0% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 53.7% | Coming soon |
| SWE Multilingual | Coming soon | 47.3% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 83.1 (Unranked · 2 rankable rows)
- Kimi K2 public-lane score: 62.3 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 80.1 (Unranked · 1 rankable row)
- Kimi K2 public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 65.4 (Estimated · #33/184)
- Kimi K2 public-lane score: 36.1 (Estimated · #129/184)

| Benchmark | GPT-5.3 Codex | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| MMLU | Coming soon | 89.5% | Coming soon |
| GPQA | Coming soon | 75.1% | Coming soon |
| SuperGPQA | Coming soon | 57.2% | Coming soon |
| MMLU-Pro | Coming soon | 81.1% | Coming soon |
| SimpleQA | Coming soon | 31% | Coming soon |
| HLE | Coming soon | 4.7% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: 92.6 (#18/148)
- Kimi K2 public-lane score: 48.4 (#96/148)

| Benchmark | GPT-5.3 Codex | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 89.8% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- GPT-5.3 Codex public-lane score: Coming soon
- Kimi K2 public-lane score: 0 (#12/12)

| Benchmark | GPT-5.3 Codex | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| AIME 2024 | Coming soon | 69.6% | Coming soon |
| AIME 2025 | Coming soon | 49.5% | Coming soon |
| MATH-500 | Coming soon | 97.4% | Coming soon |

## FAQ

### Is there enough evidence to pick between GPT-5.3 Codex and Kimi K2?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-5.3 Codex vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-vs-gpt-5-3-codex-spark)
- [Kimi K2 vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-spark-vs-kimi-k2)
- [GPT-5.3 Codex vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-5-3-codex)
- [Kimi K2 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-kimi-k2)

## Explore More

- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Kimi K2 profile](/models/kimi-k2)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)