Claude AI All Models Available: Opus 4.5, Sonnet 4.5, Haiku 4.5, 3-Series Legacy, and How to Choose the Right Tier
- Graziano Stefanelli
- 15 minutes ago
- 3 min read
Anthropic’s Claude family now covers a broad spectrum of model sizes, features, and context windows — ranging from cutting-edge “frontier” reasoning in Opus 4.5 to ultra-fast, budget-friendly inference in Haiku 4.5 and reliable legacy support from the Claude 3 series.
Understanding how these models differ by architecture, context capacity, access route, and cost is crucial for anyone selecting a Claude version for research, document workflows, chat automation, or agent-based tasks in late 2025/2026.
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Claude 4.5 family introduces Opus, Sonnet, and Haiku — each optimized for different priorities and workloads.
Claude Opus 4.5 is Anthropic’s flagship, high-logic model built for enterprise research, advanced coding, agent chains, and massive context workloads.
Claude Sonnet 4.5 balances reasoning depth and cost, excelling at structured analysis, coding, and extended chat, with an “extended-thinking” toggle for heavy Q&A.
Claude Haiku 4.5 delivers near-frontier results at minimal latency and low price, making it the default for everyday chat and document tasks.
Legacy Claude 3 variants — Opus 3, Sonnet 3, and Haiku 3 — remain supported on certain APIs and partner clouds for backward compatibility and bulk automation.
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Claude 4.5 Model Family Overview
Model | Context Window | Max Output Tokens | Best For |
Opus 4.5 | 1 048 576 tokens | 64 000 | Large projects, coding, multi-step agents |
Sonnet 4.5 | 200 000 tokens | 64 000 | Hybrid reasoning, extended chat |
Haiku 4.5 | 200 000 tokens | 64 000 | Fast Q&A, document tasks |
Opus 3 / Sonnet 3 / Haiku 3 | 200 000 tokens | 32 000 | Automation, low-cost jobs |
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Context window and output token limits scale with model size and subscription level.
Opus 4.5 offers a true “frontier” experience with 1 million token context — perfect for ingesting full books, multi-document corpora, or large codebases.
Sonnet 4.5 and Haiku 4.5 provide 200 000-token windows, sufficient for most research, compliance, or analytical workloads.
All Claude 4.5 models output up to 64 000 tokens per response, supporting ultra-long reports, detailed summaries, and rich code reviews.
Legacy Claude 3 models are capped at 32 000 output tokens and lack the efficiency, cost benefits, and accuracy of the newer 4.5 architecture.
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Claude Context Window Comparison
Model | Context Window | Output Tokens | Notes |
Opus 4.5 | 1 048 576 | 64 000 | Enterprise, frontier use |
Sonnet 4.5 | 200 000 | 64 000 | Pro, extended tasks |
Haiku 4.5 | 200 000 | 64 000 | Free, fast jobs |
Claude 3 series | 200 000 | 32 000 | Legacy, cost-saving |
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Pricing, access, and plan features vary from free Haiku to premium Opus and business enterprise tiers.
Claude Haiku 4.5 anchors the free tier with periodic refreshes and fast, accurate results for general use.
Sonnet 4.5 is available in Claude Free and Pro ($20/month), offering higher quotas and switching between Sonnet and Haiku as needed.
Opus 4.5 is reserved for Claude Pro and enterprise API users, with pricing at $5 per million input tokens and $25 per million output tokens.
Enterprise plans provide pooled usage, SAML SSO, audit logs, and 24/7 support for regulated or large-scale teams.
Legacy 3-series models remain supported for cost-sensitive workloads through at least 2027.
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Claude Plan and Pricing Comparison
Tier | Included Models | Key Limits | Monthly Cost |
Free | Haiku 4.5, Sonnet 4.5 | Usage refresh every 5h | $0 |
Pro | Haiku 4.5, Sonnet 4.5, Opus 4.5 | Quotas, API access | $20 |
Enterprise | All | Pooled quota, compliance | Custom |
Legacy | Opus 3, Sonnet 3, Haiku 3 | Lower cost, API only | Usage-based |
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Selecting the right Claude model depends on document size, workload complexity, and required reasoning depth.
Choose Opus 4.5 for full-book summarization, complex agent workflows, coding tasks, and enterprise R&D.
Use Sonnet 4.5 for advanced Q&A, structured reporting, hybrid analysis, and chat pipelines where cost efficiency is needed.
Pick Haiku 4.5 for instant chat, document review, and light analysis — especially on the free tier or when speed is more important than deepest logic.
Deploy Claude 3 series for automation or compatibility with older projects, especially when costs are critical.
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Claude Model Selection Table
Use Case | Best Model | Why |
Large document review | Opus 4.5 | 1 M context, premium output |
Analytical Q&A | Sonnet 4.5 | Hybrid, extended thinking |
Chatbots, summaries | Haiku 4.5 | Fast, efficient |
Cost-driven jobs | Sonnet 3, Haiku 3 | Cheapest, API-first |
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Anthropic’s roadmap promises Opus 5 previews and broader multimodal capabilities in all Claude families.
Upcoming Opus 5 models will introduce advanced vision, audio, and agentic skills — extending Claude’s role in web navigation and autonomous workflows.
Sonnet and Haiku will receive larger context windows, lower price points, and enhanced safety guardrails as Anthropic expands access to regulated industries.
Legacy Claude 3 APIs will continue supporting legacy automation and cost-effective scripting well into 2027.
With clear distinctions in capability, price, and supported use cases, Claude’s evolving lineup lets users match the right model to each project, from small chatbots to full-scale document automation.
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