# GPT-5.3 Codex vs Kimi K2.7 Code

> GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 43.0 on the Noometry Index. Kimi K2.7 Code costs 2.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-kimi-k2-7-code
- Last updated: 2026-10-10
- Shared benchmarks: 5

## Summary

- They share 5 benchmarks with published results for both. GPT-5.3 Codex scores higher in 2 categories and Kimi K2.7 Code in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 47.8 to 23.9.
- The biggest single-benchmark swing is WeirdML: 79.3% for GPT-5.3 Codex and 54.1% for Kimi K2.7 Code.
- Kimi K2.7 Code is cheaper at $0.95 / $4 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- GPT-5.3 Codex accepts more context: 400K tokens versus 262K.
- Kimi K2.7 Code has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Noometry Index | 45.5 | 43.0 |
| Rank | 61 | 90 |
| Context | 400K | 262K |
| Input $/M | $1.75 | $0.95 |
| Output $/M | $14 | $4 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.3 Codex: 48.5 (#51)
- Kimi K2.7 Code: 42.4 (#92)

| Benchmark | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| LMArena WebDev | 1408 | 1473 |
| WeirdML | 79.3% | 54.1% |
| ALE-Bench | 1,655 | 886.23 |
| SWE-bench Verified | 74.8% | — |
| DeepSWE | — | 30.5% |
| FrontierCode | — | 30.1% |
| SciCode | — | 47.5% |

## Agentic & Tool Use

- GPT-5.3 Codex: 47.8 (#9)
- Kimi K2.7 Code: 23.9 (#115)

| Benchmark | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| Vending-Bench 2 | 5,940 | 5,083 |
| Terminal-Bench | 78.4% | — |
| APEX-Agents | — | 37.6% |
| GBAEval | — | 0.9% |
| METR Time Horizons | 74.5% | — |

## Reasoning

- GPT-5.3 Codex: —
- Kimi K2.7 Code: 38.2 (#56)

| Benchmark | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| Epoch Capabilities Index | 156.84 | 150.01 |
| SimpleBench | — | 57.9% |
| CritPt | — | 10% |
| Chess Puzzles | — | 21% |
| Surface Evolver Bench | — | 48.8% |

## Math

- GPT-5.3 Codex: —
- Kimi K2.7 Code: 52.6 (#39)

| Benchmark | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 54% |
| FrontierMath Tier 4 | — | 12.2% |
| OTIS Mock AIME 2024-2025 | — | 95.6% |

## Knowledge

- GPT-5.3 Codex: —
- Kimi K2.7 Code: 53.6 (#51)

| Benchmark | GPT-5.3 Codex | Kimi K2.7 Code |
|---|---|---|
| GPQA Diamond | — | 87.9% |
| SimpleQA Verified | — | 36.5% |

## FAQ

### Is GPT-5.3 Codex better than Kimi K2.7 Code?

GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 43.0 on the Noometry Index. Kimi K2.7 Code costs 2.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

### Which is cheaper, GPT-5.3 Codex or Kimi K2.7 Code?

Kimi K2.7 Code is cheaper. It lists at $0.95 per million input tokens and $4 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

### Is GPT-5.3 Codex or Kimi K2.7 Code better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.5 versus 42.4 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5.3 Codex and Kimi K2.7 Code share?

5 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Kimi K2.7 Code has 19.