Anthropic Claude Models Guide: Every Model Compared (2026)

Anthropic’s current Claude lineup has 4 public models: Fable 5.1, Opus 5.5, Sonnet 5.5, and Haiku 5.5, and Opus 5.5 is the right starting point for most workloads. All 4 share a 1M-token context window, 128K output tokens, and a June 2026 knowledge cutoff, so price and speed separate them more than raw features do.

I went through Anthropic‘s model documentation and pricing pages in October 2026 and scanned dozens of recent Reddit threads on how people choose between the tiers. My pick: start on Opus 5.5, move routine work to Sonnet 5.5 or Haiku 5.5, and keep Fable 5.1 for jobs where cheaper models fail.

For the competitor view, see our Claude vs ChatGPT comparison.

How I Researched This Guide

Every spec and price here comes from Anthropic’s official model overview, pricing page, and model-selection guide, checked in October 2026. I added community signals from Reddit threads collected through Apify on r/ClaudeAI, r/ClaudeCode, and r/claude.

This is a documentation and pricing review, not a benchmark. I did not run the models side by side, so quality claims are limited to what Anthropic documents and what users report.

Which Claude Models Are Current in 2026?

Four Claude models are current: Fable 5.1 for the hardest work, Opus 5.5 for agentic coding and knowledge work, Sonnet 5.5 for everyday speed and intelligence, and Haiku 5.5 for high-volume, low-latency tasks. The table below lists the specs Anthropic publishes for each.

Model	API ID	Best for	Speed	Input / output price per MTok
Claude Fable 5.1	claude-fable-5-1	Demanding reasoning, long-horizon agents	Slower	$10 / $50
Claude Opus 5.5	claude-opus-5-5	Long-running agentic coding, knowledge work	Moderate	$4 / $20
Claude Sonnet 5.5	claude-sonnet-5-5	Best mix of speed and intelligence	Fast	$2 / $10
Claude Haiku 5.5	claude-haiku-5-5	Classification, extraction, routing, sub-agents	Fastest	From $0.10 / $0.50

All 4 models accept text and image input, return text, use adaptive thinking, and support tool use. Anthropic commits to keeping them available until at least September 1, 2027 for Fable 5.1, September 22, 2027 for Opus 5.5, September 28, 2027 for Sonnet 5.5, and October 7, 2027 for Haiku 5.5.

What Is Claude Fable 5.1?

Claude Fable 5.1 is Anthropic’s most capable model open to all customers, built for demanding reasoning and long-horizon agentic work. It extends Claude Fable 5 with stronger long-running coding, knowledge work, and research at the same prices, with cache reads at 2.5% of the base input price.

Anthropic’s documentation recommends it for agent sessions that run for hours, multistep deep research, and analysis carried through to a finished document, spreadsheet, or deck. It costs $10 per million input tokens, which is 2.5 times Opus 5.5.

The honest trade-off is speed and cost. Anthropic’s own guidance says to move to Fable only when your tests on Opus 5.5 at xhigh or max effort still fall short.

What Is Claude Opus 5.5?

Claude Opus 5.5 is the default recommendation in Anthropic’s documentation for most workloads, built for long-running agentic coding and knowledge work. It costs $4 per million input tokens and $20 per million output tokens, which is lower than the $5 and $25 charged for Opus 5 and Opus 4.8.

Its default effort level is medium, and adaptive thinking is always on. That matters if your code forces tool use, turns thinking off, or uses the computer_20251124 tool, because Anthropic lists breaking changes for those cases in its migration guide.

Use it for multi-hour coding agents, large refactors, complex systems engineering, and vision-heavy work. For a coding-tool angle, read our Claude Code vs Cursor comparison.

What Is Claude Sonnet 5.5?

Claude Sonnet 5.5 is the speed-and-intelligence model, priced at $2 per million input tokens and $10 per million output tokens. Anthropic positions it for code generation, data analysis, content creation, visual understanding, and agentic tool use.

Its default effort level is high, and it is rated “Fast” against Opus 5.5’s “Moderate.” Prompt cache reads cost 5% of the base input price, or $0.10 per million tokens.

Sonnet 5.5 costs half of Opus 5.5 on both input and output. Reddit users in r/ClaudeCode debate whether running it above medium effort pays off, and that question is worth testing on your own prompts.

What Is Claude Haiku 5.5?

Claude Haiku 5.5 is the fastest and cheapest current model, priced from $0.10 per million input tokens and $0.50 per million output tokens for prompts up to 100,000 tokens. Anthropic recommends it for real-time applications, high-volume processing, cost-sensitive deployments, and sub-agent tasks.

Pricing steps up for long prompts. Above 100,000 tokens, Haiku 5.5 costs $0.50 input and $2.50 output per million tokens.

For short prompts, Opus 5.5 costs exactly 40 times more than Haiku 5.5 on both input ($4 vs $0.10) and output ($20 vs $0.50). That 40x gap explains why r/ClaudeCode treats Haiku as the default for Explore-style sub-agents.

What Is Claude Mythos 5.1?

Claude Mythos 5.1 offers the same capabilities as Fable 5.1 but only to organizations verified through Anthropic’s programs, such as the Cyber Verification Program. It is priced like Fable 5.1 at $10 input and $50 output per million tokens.

Most readers cannot select it. Anthropic lists it as limited availability, so it sits outside the normal model picker.

Which Claude Models Are Legacy or Retired?

Anthropic still serves 9 legacy models: Fable 5, Opus 5, Opus 4.8, Opus 4.7, Opus 4.6, Opus 4.5, Sonnet 5, Sonnet 4.6, and Haiku 4.5. Four older models are retired except on cloud partners: Opus 4.1 and Sonnet 4 remain on Bedrock and Google Cloud, while Opus 4 and Haiku 3.5 remain only on Google Cloud.

Legacy models keep their old prices, so the newer models often cost less:

• Opus 5.5 at $4 / $20 undercuts Opus 5 and Opus 4.8 at $5 / $25.
• Sonnet 5.5 at $2 / $10 undercuts Sonnet 4.6 at $3 / $15.
• Haiku 5.5 at $0.10 / $0.50 undercuts Haiku 4.5 at $1 / $5.

If you still call a pinned legacy ID, check the retirement notes on Anthropic’s model deprecations page before building on it.

How Much Does Each Claude Model Cost?

Claude API pricing runs from $0.10 to $10 per million input tokens and $0.50 to $50 per million output tokens across the 4 current models. Batch API requests get 50% off, and cache reads cost a fraction of the base input price.

Model	Input	Output	5-minute cache write	Cache read
Fable 5.1	$10	$50	$12.50	$0.25
Opus 5.5	$4	$20	$5	$0.20
Sonnet 5.5	$2	$10	$2.50	$0.10
Haiku 5.5 (up to 100K prompt)	$0.10	$0.50	$0.125	$0.01

A workload of 10 million input tokens and 2 million output tokens costs $200 on Fable 5.1, $80 on Opus 5.5, $40 on Sonnet 5.5, and $2 on Haiku 5.5 at list prices. Those figures assume prompts under 100K tokens and no caching or batch discounts.

Which Claude Model Should You Use?

Use Opus 5.5 by default, Sonnet 5.5 for faster everyday work, Haiku 5.5 for volume, and Fable 5.1 only when evaluations show the cheaper models fall short. Anthropic’s own selection matrix backs this order, and it adds that tuning the effort parameter is often a better lever than switching models.

Match the model to the job with this 4-step rule set:

1. Start with Opus 5.5 for coding agents, large refactors, and complex enterprise work.
2. Drop to Sonnet 5.5 for code generation, data analysis, and content when latency matters.
3. Route classification, extraction, and sub-agent tasks to Haiku 5.5.
4. Escalate to Fable 5.1 for multi-hour agent sessions and deep research.

Build a small evaluation set from your real prompts before committing. Anthropic calls that the most important step in picking a model.

What Do Developers on Reddit Say About Choosing a Claude Model?

The most-discussed question is whether cheap Haiku 5.5 can replace Opus 5.5 for routine work. The Haiku 5.5 launch thread on r/ClaudeAI drew 2,383 upvotes and 329 comments, and a r/ClaudeCode thread titled “Haiku 5.5 is 40x cheaper than Opus 5.5” reached 740 upvotes.

Other recurring questions come straight from thread titles:

• “Is it better to use Opus on low reasoning or Sonnet on high reasoning?”
• “Is Haiku 5.5 good enough to be your main coding agent?”
• “How do you decide which Claude model to use?”

These threads show real demand for a routing answer, but they are anecdotes. Treat the posted cost comparisons as starting points and verify them on your own tasks.

How Do Claude Plans Map to These Models?

Claude’s consumer plans start free and rise to $100 per month for Max, with Pro at $17 per month on annual billing or $20 month to month. Anthropic’s pricing page lists these plans, and usage limits reset on a rolling 5-hour window.

Plan	Price	What it adds
Free	$0	Everyday chat on web, desktop, and mobile; up to 5 projects
Pro	$17/mo annual ($200 up front) or $20/mo monthly	At least 5x Free usage per session; Claude Code, Opus, and Research
Max	From $100/mo	5x or 20x Pro usage; higher output limits
Team	$20/seat/mo annual or $25 monthly (Standard)	2 to 150 users; Premium seats at $100 annual or $125 monthly
Enterprise	$20/seat/mo plus usage at API rates	SSO, SCIM, audit logs; 20-seat minimum

For the full cross-vendor cost picture, see our AI chatbot pricing comparison.

Frequently Asked Questions (FAQ)

What is the newest Claude model?

Claude Fable 5.1 is the most capable current model, and Opus 5.5, Sonnet 5.5, and Haiku 5.5 are the other 3 current public models. Claude Mythos 5.1 matches Fable 5.1 but is limited to verified organizations.

What is the difference between Claude Opus, Sonnet, and Haiku?

Opus is the high-capability tier, Sonnet balances speed and intelligence, and Haiku is the fastest and cheapest. In the 5.5 generation they cost $4, $2, and $0.10 per million input tokens.

Which Claude model is best for coding?

Opus 5.5 is the best starting point for long-running agentic coding, and Sonnet 5.5 handles everyday code generation at half the price. Fable 5.1 is the escalation path for the hardest work.

How big is the Claude context window?

Every current Claude model has a 1M-token context window, roughly 555,000 words on the current tokenizer. Maximum synchronous output is 128K tokens.

Is Claude free to use?

Yes, Claude has a free plan with everyday chat on web, desktop, and mobile. Paid plans start at Pro for $17 per month billed annually.

Which Claude model is cheapest?

Claude Haiku 5.5 is the cheapest current model at $0.10 per million input tokens for prompts up to 100,000 tokens. Prompts above that size cost $0.50 per million input tokens.

How does Claude compare with Gemini?

Both vendors offer a tiered lineup with a 1M-token context window, but prices and plan limits differ. Read our Claude vs Gemini 2025 comparison and the companion Google Gemini models guide.

Final Verdict

Opus 5.5 is the best default Claude model in 2026, Sonnet 5.5 is the best value for everyday work, Haiku 5.5 is the best for volume, and Fable 5.1 is the premium option for the hardest jobs. The 40x price gap between Opus 5.5 and Haiku 5.5 on short prompts makes routing the biggest cost lever you have.

Confirm every figure on Claude’s pricing page and Anthropic’s model overview before you budget, since plans and prices changed several times during 2026. For wider comparisons, see the best AI models hub or the AI Comparison homepage.