# GPT-5-Codex vs Inkling

> Inkling is the stronger model overall, scoring 44.1 to 37.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-codex-vs-inkling
- Last updated: 2026-10-12
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5-Codex scores higher in 2 categories and Inkling in 1 category; 3 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Inkling leads 40.4 to 30.9.
- The biggest single-benchmark swing is WeirdML: 54.5% for GPT-5-Codex and 32.3% for Inkling.
- Inkling is cheaper at $1.87 / $4.68 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- GPT-5-Codex accepts more context: 400K tokens versus 66K.
- Inkling has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5-Codex | Inkling |
|---|---|---|
| Provider | OpenAI | Thinking Machines Lab |
| Noometry Index | 37.9 | 44.1 |
| Rank | 192 | 80 |
| Context | 400K | 66K |
| Input $/M | $1.25 | $1.87 |
| Output $/M | $10 | $4.68 |
| Weights | Proprietary | Open |

## Coding

- GPT-5-Codex: 42.4 (#103)
- Inkling: 34.5 (#234)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| WeirdML | 54.5% | 32.3% |
| FrontierCode | — | 14% |
| LMArena WebDev | — | 1413 |
| FrontierSWE | — | 4.1% |
| SciCode | — | 47% |
| LMArena Coding | — | 1464 |
| ALE-Bench | — | 946 |

## Agentic & Tool Use

- GPT-5-Codex: 31.0 (#72)
- Inkling: 29.6 (#85)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| Terminal-Bench | 44.3% | — |
| APEX-Agents | — | 33.8% |
| τ²-bench Banking | — | 25% |

## Reasoning

- GPT-5-Codex: 30.9 (#83)
- Inkling: 40.4 (#56)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| ARC-AGI-2 | — | 36.5% |
| SimpleBench | — | 50% |
| Kagi LLM Benchmark | 70.3% | — |
| ARC-AGI-1 | — | 79.5% |
| CritPt | — | 5.4% |
| Chess Puzzles | — | 21% |
| LMArena Hard Prompts | — | 1451 |
| DTBench | — | 87.5% |
| LMCA | — | 37.6% |
| Epoch Capabilities Index | — | 148.54 |

## Math

- GPT-5-Codex: —
- Inkling: 31.3 (#225)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 33.3% |
| FrontierMath Tier 4 | — | 4.9% |
| OTIS Mock AIME 2024-2025 | — | 88.9% |
| ProofBench | — | 0% |
| LMArena Math | — | 1479 |

## Knowledge

- GPT-5-Codex: —
- Inkling: 55.1 (#49)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| GPQA Diamond | — | 88.3% |
| SimpleQA Verified | — | 40.3% |
| LMArena Expert | — | 1465 |

## Multilingual

- GPT-5-Codex: —
- Inkling: 54.0 (#52)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| LMArena Non-English | — | 1434 |
| LMArena Chinese | — | 1490 |
| LMArena French | — | 1458 |
| LMArena German | — | 1446 |
| LMArena Japanese | — | 1429 |
| LMArena Korean | — | 1404 |
| LMArena Russian | — | 1429 |
| LMArena Spanish | — | 1448 |

## Instruction Following

- GPT-5-Codex: —
- Inkling: 75.1 (#71)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| LMArena Instruction Following | — | 1426 |

## Long Context

- GPT-5-Codex: —
- Inkling: 43.8 (#86)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| LMArena Longer Query | — | 1434 |

## Writing & Preference

- GPT-5-Codex: —
- Inkling: 65.2 (#51)

| Benchmark | GPT-5-Codex | Inkling |
|---|---|---|
| LMArena Text | — | 1441 |
| LMArena Creative Writing | — | 1387 |
| EQ-Bench Creative Writing | — | 1611 |
| EQ-Bench 4 | — | 1226 |
| LMArena Multi-Turn | — | 1436 |

## FAQ

### Is GPT-5-Codex better than Inkling?

Inkling is the stronger model overall, scoring 44.1 to 37.9 on the Noometry Index.

### Which is cheaper, GPT-5-Codex or Inkling?

Inkling is cheaper. It lists at $1.87 per million input tokens and $4.68 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is GPT-5-Codex or Inkling better for coding?

GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 34.5 in the Noometry coding category.

### Which has the bigger context window?

GPT-5-Codex does, with 400K tokens against 66K.

### How many benchmarks do GPT-5-Codex and Inkling share?

1 benchmark has published results for both models. GPT-5-Codex has 3 scored results on Noometry and Inkling has 41.