# Grok 4.3 vs Claude Sonnet 5

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

| | Grok 4.3 | Claude Sonnet 5 |
| --- | --- | --- |
| Lab | xAI | Anthropic |
| Access | Not served on Allocate | API only |
| Context window | n/a | 1M tokens |
| List price, input | Not served | $3 / M tokens |
| List price, output | Not served | $15 / M tokens |
| Cached input | n/a | 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 Grok 4.3 for

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

## Choose Claude Sonnet 5 for

- Judgment calls with policy context
- Customer-facing writing
- Review and escalation flows

## Common questions

### Which has the bigger context window?

Claude Sonnet 5: 1,000,000 tokens (1M) against an unlisted window for Grok 4.3.

### Can I fine-tune Grok 4.3 or Claude Sonnet 5?

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/grok-4-3-vs-sonnet-5) · [Grok 4.3](https://allocate.network/models/grok-4-3.md) · [Claude Sonnet 5](https://allocate.network/models/sonnet-5.md) · [Machine-readable catalog](https://allocate.network/catalog.json)