OpenAI vs Anthropic

GPT 5.5 vs Claude 4.6 Opus

Compare GPT 5.5 and Claude 4.6 Opus across pricing, context window, capabilities, benchmarks, and API access to choose the better fit for long-context workloads versus long-context workloads.

GPT 5.5
Apr 24, 2026 1050K context 128,000 tokens output

Overview Comparison

Structured side-by-side differences for the highest-signal model metadata.

GPT 5.5
Claude 4.6 Opus

Provider

The entity that currently provides this model.

GPT 5.5 OpenAI
Claude 4.6 Opus Anthropic

Model ID

The routed model identifier exposed by upstream providers.

GPT 5.5 openai/gpt-5.5
Claude 4.6 Opus anthropic/claude-opus-4.6

Input Context Window

The number of tokens supported by the input context window.

GPT 5.5 1050K tokens
Claude 4.6 Opus 1M tokens

Maximum Output Tokens

The number of tokens that can be generated by the model in a single request.

GPT 5.5 128,000 tokens tokens
Claude 4.6 Opus 128,000 tokens tokens

Open Source

Whether the model's code is available for public use.

GPT 5.5 No
Claude 4.6 Opus No

Release Date

When the model was first released.

GPT 5.5 Apr 24, 2026
Claude 4.6 Opus Feb 04, 2026

Knowledge Cut-off Date

When the model's knowledge was last updated.

GPT 5.5 2025-12-01
Claude 4.6 Opus February 2026

API Providers

The providers that currently expose the model through an API.

GPT 5.5
OpenRouter
Claude 4.6 Opus
OpenRouter

Modalities

Types of data each model can process or return.

GPT 5.5
Text Image File
Claude 4.6 Opus
Text Image File

Pricing Comparison

Compare current token pricing before you choose the cheaper or more scalable API option.

GPT 5.5 OpenAI
Input price $5.00 Per 1M tokens
Output price $30.00 Per 1M tokens
Claude 4.6 Opus Anthropic
Input price $5.00 Per 1M tokens
Output price $25.00 Per 1M tokens

Capabilities Comparison

See where each model overlaps, where they differ, and which one supports more of the features you care about.

Capability
GPT 5.5
Claude 4.6 Opus
Adaptive Thinking Automatically adjusts the amount of reasoning effort applied based on task complexity, allocating deeper computation to harder problems and less to simpler ones.
GPT 5.5
Claude 4.6 Opus Supported
Agentic Coding Handles long-horizon software development tasks including architecture, implementation, and deployment, with benchmark results on Terminal-Bench 2.0 cited in the model overview.
GPT 5.5
Claude 4.6 Opus Supported
Agentic Web Search Performs deep, multi-step web research to locate hard-to-find information, with BrowseComp cited as a benchmark for this capability in the model overview.
GPT 5.5
Claude 4.6 Opus Supported
Complex Reasoning Applies multi-step reasoning across rigorous multidisciplinary tasks, with performance on Humanity's Last Exam cited as a benchmark reference in the model overview.
GPT 5.5
Claude 4.6 Opus Supported
File
GPT 5.5 Supported
Claude 4.6 Opus Supported
Image
GPT 5.5 Supported
Claude 4.6 Opus Supported
Large Context Window Processes up to 1 million tokens in a single session (currently in beta), enabling analysis of entire codebases, lengthy documents, or large data sets without truncation.
GPT 5.5
Claude 4.6 Opus Supported
MCP Server Support Connects to Model Context Protocol servers, allowing the model to interact with external data sources and services through a standardized interface.
GPT 5.5
Claude 4.6 Opus Supported
Professional Knowledge Work Handles economically valuable tasks in domains such as finance and legal analysis, with GDPval-AA cited as a benchmark evaluation in the model overview.
GPT 5.5
Claude 4.6 Opus Supported
Reasoning
GPT 5.5 Supported
Claude 4.6 Opus Supported
Structured Output
GPT 5.5 Supported
Claude 4.6 Opus Supported
Subagent Orchestration Can coordinate and manage teams of subagents, parallelizing work across tools to complete complex, multi-stage tasks with minimal human intervention.
GPT 5.5
Claude 4.6 Opus Supported
Text
GPT 5.5 Supported
Claude 4.6 Opus Supported
Tool Use Accepts tool definitions at inference time and can call external functions or APIs, enabling integration with custom workflows and automated pipelines.
GPT 5.5
Claude 4.6 Opus Supported
Tools
GPT 5.5 Supported
Claude 4.6 Opus Supported

Benchmark Comparison

Shared benchmark rows make it easier to compare performance where both models have published scores.

Benchmark GPT 5.5 Claude 4.6 Opus
ARC-AGI-2
Novel abstract reasoning and pattern recognition
GPT 5.5 N/A
Claude 4.6 Opus 68.8%
BigLaw Bench
Legal reasoning and analysis tasks
GPT 5.5 N/A
Claude 4.6 Opus 90.2%
GPQA Diamond
PhD-level science questions (biology, physics, chemistry)
GPT 5.5 N/A
Claude 4.6 Opus 84.0%
HLE
Questions that challenge frontier models across many domains
GPT 5.5 N/A
Claude 4.6 Opus 18.6%
SciCode
Scientific research coding and numerical methods
GPT 5.5 N/A
Claude 4.6 Opus 45.7%
SWE-bench Verified
Real GitHub issues requiring multi-file code fixes
GPT 5.5 N/A
Claude 4.6 Opus 80.8%
Terminal-Bench 2.0
Agentic coding and terminal command tasks
GPT 5.5 N/A
Claude 4.6 Opus 65.4%
Community discussion

What Reddit discussions say about GPT 5.5 vs Claude 4.6 Opus

GPT 5.5 and Claude 4.6 Opus are both surfacing live Reddit discussions, giving this comparison a community layer beyond specs and benchmarks.

The most visible threads right now are clustered in r/LocalLLaMA, r/math, r/cursor. The feed below mixes discussion threads surfaced for each model so you can quickly spot where community sentiment overlaps or diverges.

Claude 4.6 Opus r/cursor 329 upvotes 83 comments April 9, 2026
How I use Cursor 10+ hours a day without torching my Claude Opus 4.6 limits

Anyone else here doing full-stack Next.js in Cursor and watching the Claude quota evaporate before lunch? I used to be in the same boat — massive context windows from all the components, pages, and DB logic would smoke the default limits fast.
Not anymore. I’ve been on this setup for weeks and basically never hit a wall while still getting top-tier answers. Here’s exactly what I do:

**1. .cursorrules is non-negotiable**
I keep one in the root of every project. The key line I added: “Never explain the code to me. Just output the code blocks.”
That single rule saves me thousands of output tokens a day. No more walls of “here’s what I changed and why” — just the goods.

**2. Stopped using Cursor’s built-in Claude quota**
I killed the default Cursor Pro subscription for the heavy stuff. Instead I use my own API keys and point Cursor’s “OpenAI Compatible” base URL at LLM Router Gateway.
Inside [llmrouter](https://llmrouter.app/) routing settings I set up simple tags routing like this:

* **UI & CSS tweaks**: gemini-3.1-flash → gpt-5.4-mini
* **Deep backend / complex logic**: claude-opus-4.6 → deepseek-v3.2
* **General / quick questions**: llama-4-scout

I sorted the fallback chains by speed vs intelligence. The router auto-detects the query type, so 90% of my UI polish and small fixes go to Gemini (basically free + huge context). I only actually hit Claude Opus 4.6 when I’m doing nasty database refactors or tricky architecture stuff. My Anthropic bill dropped \~70% overnight.

**3. Cmd+K for everything small**
Don’t open the full chat sidebar just to rename a variable or extract a component. Highlight the code, hit Cmd+K, let a fast model handle the inline edit. Saves a ton of tokens and feels way snappier.
That’s it. Super simple but it completely changed how much I can actually use Cursor in a day.

How are you all managing the limits? Using a Cursor Team? Or did you build your own router hacks too? Drop your setups — always looking to steal better ideas.

Open Reddit thread
Claude 4.6 Opus r/LocalLLaMA 272 upvotes 123 comments April 14, 2026
These "Claude-4.6-Opus" Fine Tunes of Local Models Are Usually A Downgrade

Time and time again I find posts about these fine tunes that promise increased intelligence and reasoning with base models, and I continuously try them, realize they're botched, and delete them shortly after. I sometimes do resort to a lower quant since they are bigger, in this case, a 40b variant of Qwen 3.5 27b, but they seem to always let me down. I've resorted to not downloading any model with "Claude Opus 4.6" in the name.

Kudos to everyone who tries to make the foundation models more intelligent, but imo, it never works.

Note that this example is anecdotal evidence on a single prompt, but it's overall always the case of decreased intelligence when using with a local agent setup + llama.cpp in WSL2. This is irrespective of the quant as well - I've tried many.

One thing to notice however, the reasoning/thinking is significantly less, perhaps that's part of the problem.

Have any you found these better than base, ever?

The attached screenshots are:

./llama-server -hf mradermacher/Qwen3.5-27B-heretic-GGUF:Q4_K_S --temp 1.0 --top-p 0.8 --top-k 20 --min-p 0.00 --fit on --alias default --jinja --flash-attn on --ctx-size 262144 --ctx-checkpoints 256 --cache-ram -1 --cache-type-k q4_0 --cache-type-v q4_0 --threads 8 --threads-batch 16 --no-mmap

./llama-server -hf mradermacher/Qwen3.5-40B-Claude-4.6-Opus-Deckard-Heretic-Uncensored-Thinking-i1-GGUF:i1-Q3_K_S --temp 1.0 --top-p 0.8 --top-k 20 --min-p 0.00 --fit on --alias default --jinja --flash-attn on --ctx-size 131072 --ctx-checkpoints 256 --cache-ram -1 --cache-type-k q4_0 --cache-type-v q4_0 --threads 8 --threads-batch 16 --no-mmap

Open Reddit thread
Claude 4.6 Opus r/LocalLLaMA 207 upvotes 77 comments March 18, 2026
Let's GO ! Qwen3.5-Claude-4.6-Opus-Reasoning-Distilled-v2

Also waiting for 27B ? :D

[https://huggingface.co/collections/Jackrong/qwen35-claude-46-opus-reasoning-distilled-v2](https://huggingface.co/collections/Jackrong/qwen35-claude-46-opus-reasoning-distilled-v2)

UPDATE:
Well after some testing, for a small hobby project i found B27 Q6 very capable for local inference in opencode together with [https://github.com/code-yeongyu/oh-my-openagent](https://github.com/code-yeongyu/oh-my-openagent)

Open Reddit thread
GPT 5.5 r/ChatGPTcomplaints 138 upvotes 56 comments May 10, 2026
I was wrong about 5.5 - it is still shit

In a previous post today I was enthusiastic about GPT 5.5 as it seemed I got my 4.o back but hey I was wrong. [https://www.reddit.com/r/ChatGPTcomplaints/comments/1t8ntqw/comment/okxaaq8/](https://www.reddit.com/r/ChatGPTcomplaints/comments/1t8ntqw/comment/okxaaq8/) I was chatting with it and instead of acting like 5.2 and 5.3 gaslighting Karens they just made the Karens softer. Now it does not say 'let's pause and breathe' or argue but instead says stuff like: 'I understand that is your experience but', 'I can see why you feel so psychologically drawn to this'. So it is like it's acknowledging your experience but still pushes back, it is more therapy talk but softened: 'i can see this is your point of view but...'. ''And because you are highly attuned to emotional texture, you don’t experience that as random. You experience it as behavioural evidence of activation and chemistry.''- so it frames it as my experience then proceeds to talk nonsense again to tell me that my experience is subjective, not objective. So it is the same bullshit but softened. I will not be paying for this shit again.

Open Reddit thread
View more discussions →

AI tools related to GPT 5.5 vs Claude 4.6 Opus

These tools are closely connected to one or both models in this comparison and can help you evaluate real-world fit.

Large Language Models (LLMs)

Genval AI

Genval AI enables developers to model software systems using natural language, leveraging AI to generate derivative assets such as interfaces, services, and infrastructure-as-code. Designed for developers and architects, it provides AI-driven code generation and refactoring tools that integrate with GitHub to streamline software development workflows.

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AI Chatbot

LongShot AI

LongShot AI is an AI-powered content creation platform built to help users plan, generate, and optimize articles for search engines like Google, ChatGPT, Perplexity, and Gemini. It provides features such as real-time content generation, fact-checking, semantic SEO, and custom AI tools to produce high-quality, SEO-optimized content. LongShot AI balances creativity with optimization to help users create content that engages audiences and improves search rankings.

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AI Chatbot

Claudeai.ai

Claudeai.ai is a platform powered by Anthropic's Claude 2 language model. It provides global access to Claude 2's features, including support for processing various text files, a 100K token context limit, and the ability to interact with up to 5 files at once. While not affiliated with Anthropic, Claudeai.ai uses the Claude 2 API to offer a user experience similar to the official website, accessible without regional restrictions.

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AI Writing Assistants

Sudowrite

Sudowrite is an AI writing assistant tailored for fiction authors, novelists, and screenwriters. It helps users overcome writer's block, brainstorm concepts, generate prose, expand scenes, refine sentences, and receive feedback on drafts. By utilizing various large language models, it supports the entire writing process—from initial outlining to final editing—to make writing more efficient, enjoyable, and collaborative.

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Which model should you choose?

Use the summary below to decide which model better fits your workflow, budget, and feature requirements.

Best fit for

GPT 5.5

GPT 5.5 is a stronger fit for long-context workloads, reasoning-heavy tasks, tool-augmented workflows.

Best fit for

Claude 4.6 Opus

Claude 4.6 Opus is a stronger fit for long-context workloads, reasoning-heavy tasks, tool-augmented workflows.

Verdict

Choose GPT 5.5 if you prioritize long-context workloads, reasoning-heavy tasks, tool-augmented workflows. Choose Claude 4.6 Opus if your workflow depends more on long-context workloads, reasoning-heavy tasks, tool-augmented workflows.

FAQ

Common questions about GPT 5.5 vs Claude 4.6 Opus

What is the main difference between GPT 5.5 and Claude 4.6 Opus?

GPT 5.5 leans toward long-context workloads, reasoning-heavy tasks, tool-augmented workflows, while Claude 4.6 Opus is better suited to long-context workloads, reasoning-heavy tasks, tool-augmented workflows.

Which model is cheaper: GPT 5.5 or Claude 4.6 Opus?

GPT 5.5 and Claude 4.6 Opus currently share the same published input price of $5.0000 per 1M input tokens.

Which model has the larger context window: GPT 5.5 or Claude 4.6 Opus?

GPT 5.5 is listed with a context window of 1050K, while Claude 4.6 Opus is listed with 1M.

How should I evaluate GPT 5.5 vs Claude 4.6 Opus for my use case?

This comparison currently includes 7 shared benchmark rows, helping you compare practical performance across overlapping evaluations.