What is GPT-5.5 best for?

coding, agent workflow, reasoning, tool-use

GPT-5.5

OpenAI flagship GPT-5.5 model for coding, agentic tasks, reasoning workflows, and Responses API integrations with 400K-token context.

AI-ready answer: 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.

GPT-5.5 is the current OpenAI flagship general-purpose model, released in April 2026 as a major update over GPT-5.2. It offers improved reasoning quality, reduced hallucination rates, and a 400,000-token context window — making it suitable for long-document understanding, extended agent sessions, and complex multi-step tasks that require sustained context retention.

The GPT-5.5 family includes three variants: GPT-5.5 (standard, for general-purpose workloads), GPT-5.5 Pro (higher compute allocation for complex reasoning), and GPT-5.5 Instant (lightweight, optimized for low-latency responses, released May 2026). All three use the OpenAI Responses API and are accessible through the OpenAI SDK, with support for vision inputs, function calling, structured output, and MCP-compatible tool integration.

For coding and agent workflows, GPT-5.5 strikes a strong balance between capability and cost — outperforming GPT-5.2 on reasoning benchmarks while maintaining broad compatibility with existing OpenAI toolchains. Teams already using the OpenAI ecosystem can upgrade from earlier GPT models with minimal code changes, while the Responses API provides the foundation for modern tool-use and agent orchestration patterns.

Provider	OpenAI
Context Window	400000
Pricing	Pricing changes frequently; verify against the official OpenAI API pricing page before production use. GPT-5.5 Pro and GPT-5.5 Instant variants have separate pricing tiers.
API Style	OpenAI Responses API
SDK	OpenAI SDK, Responses API
MCP	Works through OpenAI-compatible Agent runtimes and tool adapters.
Agent	Strong fit for tool-using, reasoning-heavy, and coding-oriented Agent workflows.
RAG	Suitable for RAG orchestration when paired with retrieval, citations, and freshness checks.
Source Freshness	recently_verified
Version Status	current
Version Boundary	GPT-5.5 (released April 23, 2026) is the current OpenAI flagship. Also available as GPT-5.5 Pro (higher compute reasoning) and GPT-5.5 Instant (lightweight, released May 5, 2026). GPT-5.5 improves hallucination rates over GPT-5.2 and extends context to 400K tokens.

Key Facts

OpenAI GPT-5.5 family includes GPT-5.5, GPT-5.5 Pro, and GPT-5.5 Instant variants.
GPT-5.5 has improved reasoning and reduced hallucination rates compared to GPT-5.2.
Use the Responses API for modern OpenAI tool and agent workflows.
400K-token context window supports long-document and extended agent tasks.

Best For

Not Ideal For

Capability Matrix

Capability	Status
Coding	Strong
Agentic Tasks	Strong
Reasoning	Very Strong
Vision	Supported

SEO

SEO Title	GPT-5.5 API, Pricing, SDK, MCP & Agent Compatibility
Description	GPT-5.5 by OpenAI: OpenAI flagship GPT-5.5 model for coding, agentic tasks, reasoning workflows, and Responses API integrations with 400K-token context.
Canonical	/model/gpt-5-2
Updated	2026-05-21

Compare

Comparison	Compared With
GPT-5.5 vs Claude Sonnet 4.6	Claude Sonnet 4.6
GPT-5.5 vs DeepSeek-V3.2	DeepSeek-V3.2
GPT-5.5 vs DeepSeek V4 (Pro-Max / Flash-Max)	DeepSeek V4 (Pro-Max / Flash-Max)
GPT-5.5 vs Gemini 2.5 Flash	Gemini 2.5 Flash
GPT-5.5 vs Claude Opus 4.7	Claude Opus 4.7
GPT-5.5 vs Gemini 3.1 Pro	Gemini 3.1 Pro
GPT-5.5 vs Grok 4.3	Grok 4.3
GPT-5.5 vs Mistral Medium 3.5	Mistral Medium 3.5
GPT-5.5 vs OpenAI o3 / o4-mini	OpenAI o3 / o4-mini

Compatibility Facts

Layer	Target	Status	Evidence	Updated
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.	2026-05-18

FAQ

What is GPT-5.5?	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.
What is GPT-5.5 best for?	GPT-5.5 is best for coding, agent workflow, reasoning, tool-use.
How should GPT-5.5 be verified before production use?	Check current pricing, availability, limits, and API behavior against the listed official and GitHub sources. This entry was updated on 2026-05-21.
How are compare pages generated?	Compare pages are generated from src/content/comparisons/*.json and model frontmatter, so each comparison remains static, source-backed, and consistent with model detail pages.
How is model source data verified?	Each model entry must include an updatedAt value, at least one official or documentation source, at least one GitHub source, and a short citation summary for every source.
How should Agent workflow compatibility be evaluated?	Agent workflow compatibility should be evaluated from API style, SDK support, tool-use notes, compatibility facts, and relationship edges rather than a single marketing label.
How should pricing be handled when model prices change frequently?	Use nullable price fields or explicit pricing notes unless pricing is verified against official provider documentation, then update sourceFreshness and lastVerified together.
What does sourceFreshness mean in ContextHub?	sourceFreshness is a static freshness marker for model facts, used by detail pages and GEO feeds to show whether sources were recently verified, need review, or are stale.
When should an OpenAI-compatible SDK path be preferred?	An OpenAI-compatible SDK path is useful when a team already has OpenAI-style clients or Agent runtimes, but provider-specific behavior must still be verified.
When should I choose a reasoning-optimized model over a general-purpose model?	Reasoning-optimized models (OpenAI o3/o4-mini, DeepSeek-V3.2) excel at math, science, multi-step analysis, and complex coding tasks where careful chain-of-thought reasoning improves accuracy. General-purpose models (GPT-5.5, Claude Sonnet 4.6, Gemini 3.1 Pro) are better for everyday chat, content generation, and tasks where speed and cost matter more than deep reasoning. For agent workflows, consider whether the task requires multi-step planning (use reasoning) or tool-use throughput (use general-purpose).
Which models offer the best multilingual support?	Mistral Large 3 offers the strongest multilingual performance among current models, supporting 10+ languages with its 675B MoE architecture. Qwen3.6 provides strong multilingual support with open-weight deployment flexibility. GPT-5.5 and Claude Opus 4.7 also offer broad multilingual capabilities though primarily optimized for English. For production multilingual deployments, evaluate models on your specific language pairs rather than relying on general benchmarks.

Relationship Facts

Source	Type	Target	Confidence
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

Sources

Name	Type	Citation	Last Verified
OpenAI API Models	docs	Official OpenAI model documentation is the primary source for API model availability and capability positioning.	2026-05-21
OpenAI Node SDK	github	GitHub SDK reference for OpenAI JavaScript and TypeScript API integration.	2026-05-21

External Resources

Links to official provider documentation, SDK repositories, and community resources for GPT-5.5. Always verify model availability, pricing, and capability details against the primary provider sources.

OpenAI API Models — Official OpenAI model documentation is the primary source for API model availability and capability positioning.
OpenAI Node SDK — GitHub SDK reference for OpenAI JavaScript and TypeScript API integration.