Available models
| Model | Context | Strengths | Premium? |
|---|---|---|---|
| Claude Opus 4.6 | 200k | Most capable Claude; complex reasoning, research, long-form analysis | Yes |
| Claude Sonnet 4.6 | 200k | Balanced speed + quality; excellent coding and writing | Yes |
| Claude Sonnet 4.5 | 200k | Strong all-rounder; previous minor version | Yes |
| Claude Sonnet 4.1 | 200k | Previous generation; reliable and well-tested | Yes |
| Claude Sonnet 4.0 | 200k | Previous generation flagship | Yes |
| Claude Haiku 4.5 | 200k | Fast and efficient; good for quick tasks at large context | Pro+ |
| Claude 3.5 Sonnet | 200k | Previous model generation; still highly capable | Yes |
| Claude 3.5 Haiku | 200k | Previous gen fast model | Pro+ |
Claude’s strengths
Long-document analysis
With 200k tokens of context, Claude can read and reason over very long documents without losing coherence. Send a 300-page PDF, a large codebase, or a lengthy research paper and ask questions, summarize, or extract specific information from it.Writing and editorial quality
Claude consistently produces natural, well-structured, stylistically nuanced writing. It handles tone shifts gracefully, follows editorial guidelines precisely, and produces content that reads as genuinely human.Nuanced instruction-following
Claude is trained to follow complex, multi-part instructions carefully — respecting constraints, format requirements, and conditional rules in a single prompt without requiring repeated correction.Safe and helpful responses
Anthropic’s safety research is built into Claude’s training, making it thoughtful about sensitive topics and generally more likely to acknowledge uncertainty than to confidently produce incorrect information.Extended thinking (reasoning)
Claude Sonnet 4.6, Claude Sonnet 4.5, and Claude Opus 4.6 support extended thinking — Anthropic’s reasoning capability that allows Claude to work through complex problems step by step before producing a final answer. When you select one of these models in ZeroTwo, a thinking level slider appears in the prompt bar:| Level | Behavior |
|---|---|
| Low | Light thinking — fast responses with some structured reasoning |
| Medium | Balanced depth — good default for most complex tasks |
| High | Deep, extended reasoning — most thorough; slower and uses more quota |
Best use cases
Long document analysis
Feed entire PDFs, contracts, codebases, or research papers. Ask questions, extract, compare, or summarize with 200k context.
Writing and content
Long-form articles, essays, reports, scripts, email drafts, and editorial work. Claude’s writing is natural and stylistically precise.
Complex coding
Architecture decisions, debugging, refactoring, code review, and multi-file reasoning. Claude Sonnet 4.6 is a strong coding model.
Research synthesis
Synthesizing multiple sources, building structured analyses, and producing well-reasoned conclusions from complex information.
Choosing a Claude model
- Claude Opus 4.6: Use for the most demanding tasks — complex research, lengthy synthesis, problems requiring maximum reasoning capability. Slowest and highest-cost per message.
- Claude Sonnet 4.6: The best default for most tasks. Excellent balance of capability and speed. Strong coding, writing, and reasoning. This is Anthropic’s current recommended general-purpose model.
- Claude Haiku 4.5: Use when you need fast responses at 200k context — iterative workflows, quick Q&A over long documents, high-frequency tasks.
Related
Reasoning models
How extended thinking works and when to use High thinking level.
Premium vs. Standard
Claude models are premium — understand quota and fallback behavior.
OpenAI models
Compare with GPT-5, GPT-4o, and the o-series.
Google Gemini
Compare with Gemini 2.5 Pro and 1M-token context models.