Anthropic Claude (foundation models) vs xAI Grok 4
Anthropic Claude (foundation models) vs xAI Grok 4: side-by-side comparison of two foundation models (substrate reference) systems — architecture, taxonomy, license, pricing, MCP/A2A support, and direct edges.
Cost & capability
| Anthropic Claude (foundation models) | xAI Grok 4 | |
|---|---|---|
| Capability band | frontier | frontier |
| Capability composite | 94 | 88 |
| Cost tier | premium | premium |
| $/Mtok input | 5 | 3 |
| $/Mtok output | 25 | 15 |
| Use cases | Scoped Agentic, Code Generation Focused, Analytical Summarization, Memory Augmented Chat | Scoped Agentic, Code Generation Focused, Analytical Summarization, Memory Augmented Chat |
Where they differ (12)
Rows where both sides have data and the values disagree — the shortlist of dimensions that actually distinguish these two systems.
| Anthropic Claude (foundation models) | xAI Grok 4 | |
|---|---|---|
| Capability composite | 94 | 88 |
| $/Mtok input | 5 | 3 |
| $/Mtok output | 25 | 15 |
| Type | Frontier foundation model family (Sonnet 4 / Opus 4.5 / Haiku 4.5) | Frontier foundation model from xAI (Grok 4) |
| Created | 2023-03 (Claude 1); 2024-06 (Claude 3 Opus/Sonnet/Haiku); 2024-10 (Claude 3.5 Sonnet); 2025-02 (3.7 Sonnet); 2025-05 (Claude 4 Sonnet/Opus); 2025-09 (Sonnet 4.5); 2025-11 (Opus 4.5 + Haiku 4.5) | 2023-07 (xAI founded); 2023-11 (Grok 1); 2024-08 (Grok 2); 2025-02 (Grok 3); 2025-07 (Grok 4) |
| Latest release | Claude Opus 5.5 (2026-09-22); Claude Fable 5.1 (2026-09-01); Sonnet 5.5 + Haiku 5.5 current | Grok 4.7 (2026-09-21) |
| Pricing | API per 1M in/out: Fable 5.1 $10/$50; Opus 5.5 $4/$20; Sonnet 5.5 $2/$10; Haiku 5.5 from $0.10/$0.50 | API: Grok 4.7 $2 in / $6 out per 1M (prompts ‹200k tokens; $4 / $12 above); consumer via X / SuperGrok subscriptions |
| Funding | $65B Series H at $965B post-money (2026-05-28); S-1 filed for a proposed IPO (2026-10-26) | xAI merged into SpaceX (announced 2026-02-02, combined ~$1T); prior $20B Series E (2026-01, ~$230B valuation) |
| Deployment | Managed-only — Claude API/Platform plus Amazon Web Services, Google Cloud and Microsoft Azure | Managed-only — xAI API, grok.com, X apps; also via Amazon Bedrock, Microsoft Foundry, GitHub Copilot (older Grok-1 / Grok 2 weights downloadable) |
| API surface | REST + SDK (Python, TS, Java, Go, Ruby); also via AWS Bedrock + GCP Vertex AI APIs | REST + SDK (Python, TS); OpenAI-compatible |
| Optimised for | reasoning, code, agentic tool-use, long-form writing, safety/alignment | real-time information (X firehose access); contrarian / less-filtered persona; benchmark frontier-tier reasoning |
| Anti-fit | not for image generation; not for audio synthesis (text-output only); high cost at Opus tier; 200k context smaller than Gemini 3 (10M) | X/Twitter integration is unique selling point but creates Musk-political-association risk; weights closed at Grok 4 tier; no on-prem; less polished tool-use than Claude/GPT |
At a glance
| Anthropic Claude (foundation models) | xAI Grok 4 | |
|---|---|---|
| Section | Foundation models (substrate reference) | Foundation models (substrate reference) |
| Tier | T1 | T1 |
| Type | Frontier foundation model family (Sonnet 4 / Opus 4.5 / Haiku 4.5) | Frontier foundation model from xAI (Grok 4) |
| Created | 2023-03 (Claude 1); 2024-06 (Claude 3 Opus/Sonnet/Haiku); 2024-10 (Claude 3.5 Sonnet); 2025-02 (3.7 Sonnet); 2025-05 (Claude 4 Sonnet/Opus); 2025-09 (Sonnet 4.5); 2025-11 (Opus 4.5 + Haiku 4.5) | 2023-07 (xAI founded); 2023-11 (Grok 1); 2024-08 (Grok 2); 2025-02 (Grok 3); 2025-07 (Grok 4) |
| Latest release | Claude Opus 5.5 (2026-09-22); Claude Fable 5.1 (2026-09-01); Sonnet 5.5 + Haiku 5.5 current | Grok 4.7 (2026-09-21) |
| License | — | proprietary (Grok 4); older open weights: Grok-1 (Apache-2.0) and Grok 2 (Grok 2 Community License) |
| GitHub | — | github.com/xai-org/grok-1 ~50k stars (older Grok 1 weights only) |
| Pricing | API per 1M in/out: Fable 5.1 $10/$50; Opus 5.5 $4/$20; Sonnet 5.5 $2/$10; Haiku 5.5 from $0.10/$0.50 | API: Grok 4.7 $2 in / $6 out per 1M (prompts ‹200k tokens; $4 / $12 above); consumer via X / SuperGrok subscriptions |
| Funding | $65B Series H at $965B post-money (2026-05-28); S-1 filed for a proposed IPO (2026-10-26) | xAI merged into SpaceX (announced 2026-02-02, combined ~$1T); prior $20B Series E (2026-01, ~$230B valuation) |
| Deployment | Managed-only — Claude API/Platform plus Amazon Web Services, Google Cloud and Microsoft Azure | Managed-only — xAI API, grok.com, X apps; also via Amazon Bedrock, Microsoft Foundry, GitHub Copilot (older Grok-1 / Grok 2 weights downloadable) |
| API surface | REST + SDK (Python, TS, Java, Go, Ruby); also via AWS Bedrock + GCP Vertex AI APIs | REST + SDK (Python, TS); OpenAI-compatible |
| Optimised for | reasoning, code, agentic tool-use, long-form writing, safety/alignment | real-time information (X firehose access); contrarian / less-filtered persona; benchmark frontier-tier reasoning |
| Anti-fit | not for image generation; not for audio synthesis (text-output only); high cost at Opus tier; 200k context smaller than Gemini 3 (10M) | X/Twitter integration is unique selling point but creates Musk-political-association risk; weights closed at Grok 4 tier; no on-prem; less polished tool-use than Claude/GPT |
Pros & cons
Anthropic Claude (foundation models)
Pros: Frontier coding capability (Opus 4.5); strong safety profile via Constitutional AI; native computer-use + tool-use; broad SDK coverage; AWS Bedrock + GCP Vertex distribution.
Cons: 200k context smaller than Gemini 3's 10M; Opus pricing at premium tier; no open-weights option; no image / audio output; rate-limited at API tier without enterprise contract.
xAI Grok 4
Pros: Real-time X/Twitter data access (unique among frontier models); Colossus supercluster gives independent training capacity; ARC-AGI-2 leader (vendor-stated).
Cons: Owner Musk political controversy creates enterprise procurement headwind; closed weights at Grok 4; no on-prem; less mature ecosystem than Anthropic/OpenAI/Google.