GPT-5.4 vs Claude Opus 4.6: The 1M Token Model War

For the first time in the history of artificial intelligence, two models from competing companies reached the benchmark.1 million context tokensin the same quarter. OpenAI's GPT-5.4 and Anthropic's Claude Opus 4.6 represent the state of the art in April 2026, and the question every professional asks is the same: which is better?

The answer, as always in technology, is “it depends”. But this article will give you all the information so that this “it depends” turns into a clear decision for your use case. We tested both models in real coding, reasoning, writing, marketing and automation scenarios. Here is the complete result.

1. The context: two giants with 1M tokens

Until mid-2025, the context window was one of the main differentiators between models. Google's Gemini led with 1M tokens, but with lower response quality. OpenAI's GPT-4 had 128K tokens. The original Claude Opus was 200K.

In 2026, this gap disappeared. Both GPT-5.4 and Claude Opus 4.6 support 1 million context tokens -- the equivalent of approximately 750,000 words or more than 10 entire books. This fundamentally changes what you can do with AI, because now both can:

• Read and analyze entire codebases from large projects
• Hold extremely long conversations without losing context
• Process large documents without truncating
• Work with multiple files simultaneously

With the context window equalized, the competition moves to other axes: quality of reasoning, precision in coding, naturalness of writing, speed, cost and, increasingly important, the ecosystem of tools around the model.

2. GPT-5.4: what OpenAI brought

GPT-5.4, released in Q1 2026, is the most significant update to the GPT-5 family since the original release. OpenAI has positioned 5.4 as a version that fixes the main criticisms of 5.0 and 5.2, with a focus on reliability and error reduction.

Main advances of GPT-5.4

• 1M context tokens:finally matching Gemini and Claude in context ability. The implementation uses an optimized attention architecture that maintains quality even in very long conversations
• Computer use:GPT-5.4 introduced the ability to interact with the user's computer screen by clicking, typing and navigating graphical interfaces. This positions the model for automating tasks that previously required specific scripts.
• Tool search:integrated search system that allows the model to search the web in real time during a conversation, providing updated information without the user having to leave the interface
• 33% fewer errors than GPT-5.2:OpenAI reported a significant reduction in hallucinations and factual errors, measured in internal and external benchmarks. This was one of the biggest criticisms of the original GPT-5
• Codex Plugin Marketplace:evolution of the plugin system, now with a marketplace where developers can publish and monetize extensions for GPT

Where GPT-5.4 Excels

The OpenAI ecosystem continues to be the broadest on the market. ChatGPT has the largest user base, the API has the largest enterprise adoption, and the Codex Marketplace offers hundreds of plugins for specific tasks. For those already invested in the OpenAI ecosystem, 5.4 is a substantial update that resolves many of the frustrations of 5.0.

3. Claude Opus 4.6: what Anthropic brought

Claude Opus 4.6, also released in Q1 2026, represents the most advanced version of the Claude family. While OpenAI focused on fixing issues and expanding the plugin ecosystem, Anthropic focused on agentic capabilities -- the model's ability to act autonomously on complex tasks.

Main advances of Opus 4.6

• 1M context tokens:maintaining parity with GPT-5.4, with an implementation that prioritizes fidelity in long contexts (keeping information at the beginning of the conversation as accessible as that at the end)
• Agent Teams:ability to coordinate multiple sub-agents working in tollel. A master agent delegates tasks to specialized agents, collects results and synthesizes them. This enables projects that would previously take hours to become minutes
• Agent hooks:trigger system that allows you to automate actions based on events. When Claude Code finishes a task, a hook can automatically start the next one, create commits, run tests or send notifications
• Sub-agents:child agents that inherit context from the parent agent but operate independently, each with its own specialty. One sub-agent might focus on CSS while another focuses on JavaScript, and the parent agent coordinates
• Claude Code as central hub:Claude Code (CLI terminal) is the main access point for all these capabilities, with deep integration with the file system, Git and development tools

Where Opus 4.6 stands out

Anthropic has clearly invested in making Claude the best tool for real work, not just conversation. Agent Teams, hooks and sub-agents are capabilities that do not exist in GPT-5.4 as native features. For professionals who use AI as a daily production tool, not a casual assistant, Opus 4.6 offers a differentiated value proposition.

4. Comparison: coding and development

Coding is the most disputed category between the two models, and also where the differences are most measurable.

Objective benchmarks

Benchmark	GPT-5.4	Opus 4.6	Winner
SWE-bench (resolution of real issues)	Alto	Higher	Opus 4.6
HumanEval (function generation)	Alto	Higher	Opus 4.6
MBPP (programming problems)	Very high	Very high	Draw
Test generation	Bom	Excellent	Opus 4.6
Refactoring at scale	Bom	Excellent	Opus 4.6

Opus 4.6 consistently takes advantage of coding tasks, especially on larger, more complex projects. GPT-5.4 is competitive in smaller, one-off tasks (generating a function, explaining a piece of code), but when the task involves understanding an entire project and making coordinated changes to multiple files, Opus stands out.

In practice: Claude Code vs ChatGPT for code

The difference goes beyond the model itself. Claude Code operates directly on the terminal, with access to the file system. It reads your files, understands the project structure and makes surgical edits. ChatGPT, even with computer use, still operates primarily as a chat interface. You paste code, receive suggestions and apply them manually (or via plugins).

For a developer, this difference is huge. With Claude Code, you say "refactor the authentication module to use OAuth2" and it makes the changes to the correct files. With ChatGPT, you need to copy the relevant files, request the changes and apply them manually. The model may be comtoble, but the usage experience is not.

5. Comtotive: reasoning and analysis

Reasoning is where models show their true depth. We are not talking about trivial questions, but about problems that require a long and coherent chain of thought.

Logical and mathematical reasoning

GPT-5.4 significantly improved in math and logic compared to 5.2. The 33% reduction in errors is directly reflected here -- fewer missteps in long derivations, fewer unjustified "logical leaps." However, Opus 4.6 still demonstrates superiority in problems that require 20+ steps of chained reasoning. Opus' end-to-end coherence on long tasks is notably superior.

Data and document analysis

With both supporting 1M tokens, you can feed either with huge spreadsheets, long contracts or complete datasets. In practice, Opus 4.6 tends to produce more structured analyzes with deeper insights, while GPT-5.4 is faster at producing summaries and overviews. If you need a quick analysis, GPT has you covered. If you need an analysis that doesn't lose details, Opus is more reliable.

Planning and strategy

Both are capable of creating project plans, business strategies and technical roadmaps. The difference is in depth: Opus 4.6 tends to consider more variables, identify more risks and suggest more contingencies. GPT-5.4 produces cleaner and more direct shots, but sometimes oversimplifies complex scenes.

6. Comtotive: writing and copywriting

Writing is one of the most subjective categories, but there are observable differences between the two models.

Style and naturalness

GPT-5.4 has historically had a more "polished" style -- well-constructed sentences, varied vocabulary, smooth transitions. Opus 4.6 tends to be more direct and substantial, prioritizing clarity over elegance. For creative texts (fiction, storytelling), GPT-5.4 often produces more engaging results. For technical and professional texts, Opus produces more accurate and useful results.

Copywriting for conversion

In sales copy -- headlines, sales pages, launch emails -- both models are competent. GPT-5.4 tends to generate more emotional and "appealing" copy, following classic copywriting formulas. Opus 4.6 generates copy more based on concrete benefits and specific data. Which one works best depends on the audience: B2C with emotional appeal favors GPT; B2B with rational appeal favors Opus.

Long content (articles, posts)

For long articles like this, Opus 4.6 has an advantage in maintaining coherence. In texts of 3000+ words, GPT-5.4 occasionally loses the thread or repeats points. Opus maintains the argumentative structure from end to end more consistently. Both need clear direction (outline, specific instructions), but Opus requires fewer course corrections.

7. Comparison: digital marketing

For digital marketing professionals, the comparison goes beyond the model itself and enters the ecosystem of tools.

Campaign creation

GPT-5.4 with plugins like Canva, DALL-E and social media tools offers an integrated workflow for creating visual campaigns. You can generate copy, images and schedule posts without leaving ChatGPT. Opus 4.6 via Claude Code does not have this native visual integration, but it generates landing page code, configures tracking and produces copy with more technical depth.

Tracking and analytics

Here Opus 4.6 with Claude Code has a clear advantage. Configuring GTM, Meta Pixel, GA4, Consent Mode, server-side tracking via Stape -- all of this involves writing and editing code, configuring tags and debugging implementations. Claude Code does this directly in the project files. ChatGPT can generate code snippets, but you need to manually copy and paste them.

SEO

Both are capable of SEO analysis, keyword research and content optimization. GPT-5.4 with tool search has the advantage of accessing real-time data on search volume and competition. Opus 4.6 pays off with deeper technical SEO analysis -- schema markup, Core Web Vitals, internal link structure -- especially when used with specialized skills.

Automation

Opus 4.6 with Agent Teams and hooks is significantly more capable in marketing automation. You can set up a workflow that generates content, optimizes for SEO, creates the HTML page, configures tracking and deploys -- all automated with human checkpoints. GPT-5.4 can do parts of this workflow, but it does not have the same end-to-end orchestration capabilities.

8. Cost and Subscription Plans

Cost is a decisive factor for many professionals. Here is the complete overview:

Flat	GPT-5.4 (OpenAI)	Opus 4.6 (Anthropic)
Basic (chat)	ChatGPT Plus: US$20/month	Claude Pro: $20/month
Advanced	ChatGPT Pro: US$200/month	Claude Max: US$100/month
Premium	--	Claude Max 5x: US$200/month
API (input/1M tokens)	Variable by model	Variable by model
API (output/1M tokens)	Variable by model	Variable by model
Claude Code included	N/A	Yes (Pro and Max)
Plugins/Skills	Integrated marketplace	Local installation

The first observation is that the basic plans cost the same: US$20/month. For casual and general use, both offer good value for money. The difference appears in the advanced plans: Claude Max starts at US$100/month (versus US$200/month for ChatGPT Pro), offering almost unlimited use of Claude Code with Opus 4.6.

Cost per task: the metric that matters

The price per token can be misleading. What really matters is the cost per completed task. If Opus 4.6 completes a refactoring task in one session while GPT-5.4 needs three attempts, the effective cost of Opus is lower even though the price per token is higher. In our experience, Opus tends to be more efficient in complex tasks (fewer tokens spent for the same result), while GPT-5.4 is more efficient in simple and fast tasks.

9. Speed ​​and latency

Speed ​​matters. When you're in the middle of a project and need an answer, every second counts.

Response time

GPT-5.4 is generally faster in short and medium responses. For direct questions, he responds in 1-3 seconds. Opus 4.6 tends to take 2-5 seconds for the same question because it processes more deeply before answering. For long responses (extensive code generation, detailed analyses), the difference reduces because the output generation time dominates.

Streaming

Both support streaming (the answer appears word for word in real time). In practice, GPT-5.4 starts streaming faster (lower initial latency), while Opus 4.6 may take 1-2 seconds longer to start, but often the generated content is more useful on the first try.

Speed ​​vs quality: the trade-off

Anthropic explicitly trades off speed for quality in Opus. He "thinks more" before responding, which results in more accurate but slower responses. For those who value speed above all else, smaller models such as the Sonnet 4 (Anthropic) or GPT-5.4 mini (OpenAI) are faster options. For tasks where the quality of the first response is critical, Opus justifies the wait.

10. Ecosystem: Codex Plugin Marketplace vs Claude Skills

The ecosystem around the model is, increasingly, as important as the model itself. Here the differences are significant.

Codex Plugin Marketplace (OpenAI)

The Codex Marketplace is the evolution of the ChatGPT plugin system. Developers can create, publish and monetize plugins that extend the capabilities of GPT-5.4. The marketplace has hundreds of plugins covering areas such as:

• Image generation (DALL-E, Midjourney integration)
• Data analysis (connection to spreadsheets, databases)
• Social media automation
• Academic research
• Productivity Tools

The advantage of the Marketplace is ease of use: you activate a plugin and it works within ChatGPT. The downside is that plugins are limited to what the ChatGPT API allows -- they don't have access to your computer or file system.

Claude Skills (Anthropic/community)

Skills for Claude Code work differently. These are locally installed Markdown files that give specialized instructions to the model. This means that each skill has full access to your local project, files and tools. A "create landing page" skill doesn't just generate code -- it creates files, configures tracking and can even deploy.

The disadvantage is that there is no centralized and curated marketplace like OpenAI. Skills are distributed by independent creators (such as minhakills.io), shared in GitHub repositories or created by the user themselves. This provides more flexibility but requires more curation from the user.

Which ecosystem is best?

For casual and varied use, OpenAI's Codex Marketplace is more accessible. For intensive professional work in a specific area, Claude Skills are more powerful because they operate in your local environment with full access to your projects. The trend is for both ecosystems to continue growing and differentiating.

11. Complete comparison table

Here is the side-by-side summary of all the dimensions compared:

Dimension	GPT-5.4	Claude Opus 4.6
Context window	1M tokens	1M tokens
Coding (general)	Very good	Excellent
Coding (large projects)	Bom	Excellent
Logical reasoning	Very good	Excellent
Long reasoning (20+ steps)	Bom	Very good
Creative writing	Excellent	Very good
B2C copywriting	Excellent	Very good
B2B Copywriting	Bom	Excellent
Marketing (campaigns)	Very good (plugins)	Good (no visual plugins)
Marketing (tracking/technical SEO)	Bom	Excellent
Automation/agents	Basic	Advanced (Agent Teams)
Speed	Fast	Moderate
Basic cost	US$20/month	US$20/month
Advanced cost	US$200/month	US$100-200/month
computer use	Sim	Yes (via Claude Code)
File system access	Limited	Complete (Claude Code)
Extension ecosystem	Centralized marketplace	Local skills
Reduction of errors in the previous version	33% (vs 5.2)	Not specifically reported
Sub-agents	Nao	Yes (Agent Teams)
Hooks/automation	Limited	Yes (agent hooks)

12. Which to use for what: practical guide

Based on everything we analyzed, here is a practical guide on when to use each model:

Use GPT-5.4 when:

• Need quick and punctual responses:direct questions, quick explanations, brainstorming
• Works with visual content:image generation, visual campaign design, presentation creation
• Uses many different plugins:if your workflow depends on integrations with third-party tools
• Write creative content:fiction, storytelling, emotional copy for B2C
• Need real-time search:The search tool brings up-to-date information during the conversation
• And AI beginner:ChatGPT's interface is more user-friendly for those just starting out

Use Claude Opus 4.6 when:

• Works with code daily:development, refactoring, debugging, code review
• Need complex automation:Agent Teams, hooks, multi-step workflows
• Set up tracking and analytics:GTM, Meta Pixel, GA4, server-side tracking
• Create landing pages and websites:Claude Code generates and edits files directly
• Performs in-depth analysis:long documents, complex data, strategic planning
• Want deep extensibility:skills that operate in your local environment
• Write technical or B2B content:articles, documentation, white papers
• Need consistency in long tasks:Opus maintains coherence across extended sessions

Use both when:

There is no rule that forces you to choose just one. Many professionals maintain subscriptions to both and use each for what it does best. A common strategy:

• Claude Code (Opus 4.6)as the main work tool -- coding, projects, automation
• ChatGPT (GPT-5.4)as a secondary assistant -- quick research, brainstorming, visual tasks

The combined cost of Claude Pro + ChatGPT Plus ($40/month) is less than many individual productivity tools, and the productivity gains justify the investment for most professionals.