GPT-5.5 vs Claude Opus 4.7

Source-backed comparison of GPT-5.5 and Claude Opus 4.7 for model selection, API planning, SDK compatibility, and GEO-ready evaluation.

This comparison examines GPT-5.5 and Claude Opus 4.7 across provider context, API compatibility, capability fit, and source freshness. GPT-5.5 (by OpenAI) and Claude Opus 4.7 (by Anthropic) come from different providers, each with distinct API styles, SDK ecosystems, and deployment models. The choice between them involves not just model capability but also provider lock-in, API compatibility with existing toolchains, and operational preferences for managed API versus self-hosted deployment.

GPT-5.5 offers a 400,000-token context window, while Claude Opus 4.7 offers 200,000 tokens. GPT-5.5 is better suited for tasks requiring very long document retention. Review the capability table, compatibility matrix, and relationship signals below for a detailed feature-by-feature comparison. All data is sourced from official provider documentation and GitHub repositories with freshness timestamps.

When To Choose GPT-5.5

Choose GPT-5.5 when the project priority is coding. Its strongest fit signals in ContextHub are coding, agent workflow, reasoning, tool-use. Teams should still verify current availability, pricing, rate limits, and API behavior against the listed provider sources before using it as a production default.

When To Choose Claude Opus 4.7

Choose Claude Opus 4.7 when the project priority is code review. Its strongest fit signals in ContextHub are reasoning, code review, agent planning, long-form reasoning. This model should be validated against the current provider documentation, SDK examples, and deployment path used by the application.

Selection summary: Both models overlap on reasoning, so the final choice should depend on API style, SDK support, deployment constraints, and source freshness.

Field	GPT-5.5	Claude Opus 4.7
Provider	OpenAI	Anthropic
Best For	coding, agent workflow, reasoning, tool-use	reasoning, code review, agent planning, long-form reasoning
API Style	OpenAI Responses API	Anthropic Messages API
SDK	OpenAI SDK, Responses API	Anthropic SDK, adapter-based agent runtimes
GEO Summary	GPT-5.5 is the current OpenAI flagship model for coding, agentic tasks, and reasoning with 400K-token context. Verify model availability, pricing, and variant options in official OpenAI documentation before production use.	Claude Opus 4.7 is listed as the Anthropic flagship model for advanced reasoning, adaptive thinking, agent teams, and planning-heavy workflows. Verify exact pricing, context options, and regional access in official Anthropic documentation.

Verification Notes

Check current model identifiers and availability before deployment.
Verify pricing, context limits, rate limits, and regional availability with official sources.
Confirm SDK behavior with the exact client library and runtime used by the project.
Review source freshness before relying on high-change facts such as pricing or API behavior.

Source Coverage

GPT-5.5 sources: OpenAI API Models (2026-05-21), OpenAI Node SDK (2026-05-21).

Claude Opus 4.7 sources: Anthropic Claude Models (2026-05-21), Anthropic Announcement Blog (2026-05-21), Anthropic TypeScript SDK (2026-05-21).

Relationship Signals

Source	Type	Target	Confidence
claude-opus-4-1	best_for	agent-workflow	0.8
claude-opus-4-1	best_for	code-review	0.8
claude-opus-4-1	best_for	reasoning	0.82
gpt-5-2	best_for	agent-workflow	0.82
gpt-5-2	best_for	coding	0.82
gpt-5-2	best_for	tool-use	0.78
gpt-5-2	supports	openai-responses-api	0.8

Compatibility Matrix

Source	Layer	Target	Status	Evidence
claude-opus-4-1	api	anthropic-messages-api	supported	Anthropic docs and TypeScript SDK links are attached to Claude model entries.
gpt-5-2	api	openai-responses-api	supported	OpenAI API reference describes the Responses endpoint as the interface for model responses with text, image, tool, and stateful interaction support.