$ diff claude-opus-5 grok-4-5
Claude Opus 5 vs Grok 4.5
Anthropic and xAI, side by side. Every value below is the one recorded on the model’s own wiki page, with its citation — nothing is estimated.
AnthropicClaude Opus 5
- context
- 1M
- weights
- closed
- $/M in
- $5
- $/M out
- $25
- context
- 500K
- weights
- —
- $/M in
- $2
- $/M out
- $6
What actually differs
- Context window
- Claude Opus 5 takes 1M against 500K — 2× more room in a single request.
- Input price
- Grok 4.5 at $2/M against $5/M — 2.5× cheaper to feed.
- Output price
- Grok 4.5 at $6/M against $25/M — 4.2× cheaper to generate. Output dominates the bill on most agentic workloads, where the model writes far more than it reads.
- Recency
- Claude Opus 5 shipped 15 days after Grok 4.5 (2026-07-24 vs 2026-07-09).
Full spec
| Attribute | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| Developer | Anthropic | xAI |
| Released | 2026-07-24 | 2026-07-09 |
| Context window | 1M tokens | 500K tokens |
| Pricing | $5/M input · $25/M output (standard); $10/M · $50/M (Fast mode, research preview) | $2/M input · $6/M output |
| License | proprietary | not recorded |
| Availability | Claude.ai, API (`claude-opus-5`), Bedrock (`anthropic.claude-opus-53`), Vertex AI, Microsoft Foundry, Claude Code, Cowork | Grok Build (default model), Cursor (all plans), SpaceXAI console/API; not in EU (regulatory review pending as of 2026-07-09) |
Values come from Claude Opus 5 and Grok 4.5, where each is cited to its source. This page states no benchmark result and ranks neither model — it puts two published specifications next to each other. Where a lab has not published a figure, the row says so rather than guessing. How these pages are produced.