$ diff claude-opus-5 grok-build
Claude Opus 5 vs Grok Build
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
- 256K
- weights
- open
- $/M in
- $1
- $/M out
- $2
What actually differs
- Context window
- Claude Opus 5 takes 1M against 256K — 3.9× more room in a single request.
- Input price
- Grok Build at $1/M against $5/M — 5.0× cheaper to feed.
- Output price
- Grok Build at $2/M against $25/M — 12.5× cheaper to generate. Output dominates the bill on most agentic workloads, where the model writes far more than it reads.
- Weights
- Grok Build publishes weights (Apache 2.0 (CLI codebase, open-sourced 2026-07-16)); Claude Opus 5 is API-only. That decides self-hosting, air-gapped deployment and fine-tuning before any capability question does.
- Recency
- Claude Opus 5 shipped 71 days after Grok Build (2026-07-24 vs 2026-05-14).
Full spec
| Attribute | Claude Opus 5 | Grok Build |
|---|---|---|
| Developer | Anthropic | xAI |
| Released | 2026-07-24 | 2026-05-14 |
| Context window | 1M tokens | 256K tokens |
| Pricing | $5/M input · $25/M output (standard); $10/M · $50/M (Fast mode, research preview) | $1/M input · $2/M output (xAI API public beta) |
| License | proprietary | Apache 2.0 (CLI codebase, open-sourced 2026-07-16) |
| Availability | Claude.ai, API (`claude-opus-5`), Bedrock (`anthropic.claude-opus-53`), Vertex AI, Microsoft Foundry, Claude Code, Cowork | Terminal CLI (SuperGrok Heavy), Kilo Code VS Code/JetBrains (SuperGrok or X Premium+), xAI API public beta; source at github.com/xai-org/grok-build |
Values come from Claude Opus 5 and Grok Build, 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.