# GPT-5.5 vs Grok 4.3

Grok 4.3 is not currently in the Allocate serving catalog, so this page lists no prices for it: every price on this site comes from the live catalog.

## Specifications

| | GPT-5.5 | Grok 4.3 |
| --- | --- | --- |
| Lab | OpenAI | xAI |
| Access | API only | Not served on Allocate |
| Context window | 400K tokens | n/a |
| List price, input | $5 / M tokens | Not served |
| List price, output | $30 / M tokens | Not served |
| Cached input | $0.50 / M tokens | n/a |
| License | Proprietary API | Proprietary API |
| Fine-tunable | No | No |

Specifications and provider list prices from the Allocate catalog, checked 2026-07-21.

## Choose GPT-5.5 for

- Complex tool-using agents
- Code generation
- General assistants

## Choose Grok 4.3 for

- Freshness-sensitive answers
- Fast reasoning turns
- Research assistants

## Common questions

### Which has the bigger context window?

GPT-5.5: 400,000 tokens (400K) against an unlisted window for Grok 4.3.

### Can I fine-tune GPT-5.5 or Grok 4.3?

No. Both are closed models served over API. If you want a model you can train and own, start from an open-weights base in the catalog.

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[HTML page](https://allocate.network/compare/gpt-5-5-vs-grok-4-3) · [GPT-5.5](https://allocate.network/models/gpt-5-5.md) · [Grok 4.3](https://allocate.network/models/grok-4-3.md) · [Machine-readable catalog](https://allocate.network/catalog.json)