Anthropic Claude (foundation models) vs OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4)
Anthropic Claude (foundation models) vs OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4): side-by-side comparison of two foundation models (substrate reference) systems — architecture, taxonomy, license, pricing, MCP/A2A support, and direct edges.
Anthropic Claude (foundation models) · OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4)
Cost & capability
| Anthropic Claude (foundation models) | OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4) | |
|---|---|---|
| Capability band | frontier | frontier |
| Capability composite | 94 | 95 |
| Cost tier | premium | mid |
| $/Mtok input | 5 | 1.25 |
| $/Mtok output | 25 | 10 |
| 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 (13)
Rows where both sides have data and the values disagree — the shortlist of dimensions that actually distinguish these two systems.
| Anthropic Claude (foundation models) | OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4) | |
|---|---|---|
| Capability composite | 94 | 95 |
| Cost tier | premium | mid |
| $/Mtok input | 5 | 1.25 |
| $/Mtok output | 25 | 10 |
| Type | Frontier foundation model family (Sonnet 4 / Opus 4.5 / Haiku 4.5) | Frontier foundation model family (GPT-5 / GPT-4o / o3 / o4) |
| 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) | 2018 (GPT-1); 2020-06 (GPT-3); 2023-03 (GPT-4); 2024-05 (GPT-4o); 2024-09 (o1); 2025-01 (o3); 2025-08 (GPT-5) |
| Latest release | Claude Opus 5.5 (2026-09-22); Claude Fable 5.1 (2026-09-01); Sonnet 5.5 + Haiku 5.5 current | GPT-6.1 Terra (2026-10-26; computer use) and GPT-6.1 Sol; earlier GPT-6 Sol / Luna / Instant in ChatGPT (2026-10-07) and API flagship GPT-6 Astra (announced 2026-09-03) |
| 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 flagship GPT-6 Astra $10 input / $50 output per 1M tokens (Fast mode 2x price); ChatGPT Free / Go / Plus / Pro / Business / Enterprise plans |
| Funding | $65B Series H at $965B post-money (2026-05-28); S-1 filed for a proposed IPO (2026-10-26) | $57.9B+ total raised; $500B valuation (2025 secondary tender); Microsoft $13B+ strategic investment |
| Deployment | Managed-only — Claude API/Platform plus Amazon Web Services, Google Cloud and Microsoft Azure | Managed-only — OpenAI API + ChatGPT, also Microsoft Azure and AWS Bedrock (separate gpt-oss open-weight models exist) |
| API surface | REST + SDK (Python, TS, Java, Go, Ruby); also via AWS Bedrock + GCP Vertex AI APIs | REST + SDK (Python, TS, Java, Go, .NET); Azure OpenAI variant; Realtime API (WebRTC) |
| Optimised for | reasoning, code, agentic tool-use, long-form writing, safety/alignment | general-purpose reasoning, coding, multimodal, voice/real-time |
| 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) | weights closed; data residency limited (US/EU/Asia regions only); rate-limited without enterprise; no open-weights option; Sora video gated |
At a glance
| Anthropic Claude (foundation models) | OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4) | |
|---|---|---|
| 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 family (GPT-5 / GPT-4o / o3 / o4) |
| 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) | 2018 (GPT-1); 2020-06 (GPT-3); 2023-03 (GPT-4); 2024-05 (GPT-4o); 2024-09 (o1); 2025-01 (o3); 2025-08 (GPT-5) |
| Latest release | Claude Opus 5.5 (2026-09-22); Claude Fable 5.1 (2026-09-01); Sonnet 5.5 + Haiku 5.5 current | GPT-6.1 Terra (2026-10-26; computer use) and GPT-6.1 Sol; earlier GPT-6 Sol / Luna / Instant in ChatGPT (2026-10-07) and API flagship GPT-6 Astra (announced 2026-09-03) |
| License | — | proprietary (API 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 flagship GPT-6 Astra $10 input / $50 output per 1M tokens (Fast mode 2x price); ChatGPT Free / Go / Plus / Pro / Business / Enterprise plans |
| Funding | $65B Series H at $965B post-money (2026-05-28); S-1 filed for a proposed IPO (2026-10-26) | $57.9B+ total raised; $500B valuation (2025 secondary tender); Microsoft $13B+ strategic investment |
| Deployment | Managed-only — Claude API/Platform plus Amazon Web Services, Google Cloud and Microsoft Azure | Managed-only — OpenAI API + ChatGPT, also Microsoft Azure and AWS Bedrock (separate gpt-oss open-weight models exist) |
| API surface | REST + SDK (Python, TS, Java, Go, Ruby); also via AWS Bedrock + GCP Vertex AI APIs | REST + SDK (Python, TS, Java, Go, .NET); Azure OpenAI variant; Realtime API (WebRTC) |
| Optimised for | reasoning, code, agentic tool-use, long-form writing, safety/alignment | general-purpose reasoning, coding, multimodal, voice/real-time |
| 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) | weights closed; data residency limited (US/EU/Asia regions only); rate-limited without enterprise; no open-weights option; Sora video gated |
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.
OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4)
Pros: Most-deployed frontier LLM (800M+ MAU ChatGPT); full multimodal stack (vision + audio + image gen + video gen); largest ecosystem of fine-tunes / RAG / agent integrations; Azure distribution.
Cons: Closed weights; expensive at Pro/o3 tier; legal exposure (multiple ongoing NYT / Authors Guild lawsuits); Sora & advanced features behind waitlists; SWE-bench trails Claude Opus 4.5.