Which Claude Model Should You Use? A Work-by-Work Guide

The Claude model picker encourages the wrong first question. The useful question is not which model is smartest. It is which combination of model, effort, and product surface will finish this job without wasting your plan limit.

As of July 26, 2026, the lowest-regret default for most people is Claude Sonnet 5 at medium or high effort. Claude Opus 5 is the better choice when the task is ambiguous, expensive to get wrong, or likely to require several rounds of checking. Claude Fable 5 belongs on long-running frontier work where continuity and planning matter more than usage cost. Claude Haiku 4.5 is for speed, routing, and repetitive low-stakes work.

That conclusion is slightly different from Anthropic’s current product defaults. Opus 5 is now the default on Max and the strongest model on Pro, while Sonnet 5 is the default on Free and Pro. The apparent contradiction is the point: a product default is not a universal work recommendation.

The short answer

• Use Sonnet 5 for most daily work. It is the best starting point for drafting, editing, summarizing, ordinary research, routine data work, and most coding.
• Use Opus 5 when the cost of a weak first pass is high. That includes architecture, difficult debugging, conflicting-source synthesis, high-stakes analysis, and complex spreadsheet or document review.
• Use Fable 5 for work that stays hard for a long time. Large migrations, multi-day agents, broad codebase audits, and long research programs fit its official positioning. Its access and credit rules make it a poor casual default.
• Use Haiku 4.5 when volume matters more than depth. Triage, extraction, classification, formatting, quick edits, and routing are its lane.
• Do not choose a legacy model for new work by default. Use one only to reproduce an earlier result, test a migration, or support an existing integration.

Claude models at a glance

Claude Sonnet 5: the practical default

Anthropic positions Sonnet 5 as the current high-performance model for coding and agents. Its API model string is claude-sonnet-5. It is available across all plans, defaults on Free and Pro, and is also available in Claude Code and the API. API pricing is $2 per million input tokens and $10 per million output tokens through August 31, 2026, then $3 and $15. Anthropic also warns that its tokenizer can turn the same input into roughly 1.0 to 1.35 times as many tokens as Sonnet 4.6, which is one reason per-token price does not settle per-task cost. Anthropic’s Sonnet 5 announcement contains the current availability and transition pricing.

Choose Sonnet 5 when the task has a clear shape and you can inspect the answer. It gives you enough capability for most work without starting every request at the highest credit burn.

Claude Opus 5: the hard-work default

Opus 5 uses the API string claude-opus-5. It is available across Anthropic’s paid Claude surfaces, with account and administrator controls determining what appears in Team and Enterprise. Anthropic describes it as an everyday model for complex coding and professional work, makes it the Max default, and calls it the strongest option on Pro. API pricing is $5 per million input tokens and $25 per million output tokens. Fast mode runs at about 2.5 times normal speed and costs twice the base rate. Opus 5 supports adjustable effort, and thinking cannot be switched off in the Claude chat product. The launch page and model settings guide document those constraints.

Use Opus 5 when the bottleneck is judgment, not typing speed. A difficult bug, a cross-cutting refactor, a disputed research conclusion, or a financial model review can cost more in retries than the higher model rate.

Claude Fable 5: frontier capacity with a plan penalty

Fable 5 uses claude-fable-5. Anthropic positions it as next-generation intelligence for long-running agents and says its lead grows as work gets longer and more complex. API pricing is $10 per million input tokens and $50 per million output tokens. It is available on all paid plans, but access is not equal: Max and premium Team or legacy Enterprise seats can use it inside plan limits up to 50 percent of weekly usage, while Pro and standard seats use pay-as-you-go credits. Anthropic’s current Fable plan guide is the source of truth for those limits.

Fable is not the automatic answer to which Claude model is best. Opus 5 now comes close to Fable’s official capability position at half the API token price. Fable earns its premium only when your own evaluation shows fewer missed dependencies, better long-horizon planning, or less rework on the exact workflow you run.

Claude Haiku 4.5: the throughput model

Haiku 4.5 is the fastest and least expensive current Claude model. It appears in Anthropic’s paid-plan model matrix and Claude Code’s supported-model list, while exact picker visibility remains account-dependent. Its dated API string is claude-haiku-4-5-20251001, with the alias claude-haiku-4-5. API pricing is $1 per million input tokens and $5 per million output tokens. It has a 200,000-token API context window, compared with one million tokens for the current Fable, Opus, and Sonnet models, and it does not expose the current adaptive-effort controls. Anthropic’s live model overview lists the IDs, prices, context windows, and feature differences.

Haiku is the right model for work you would rather run ten times than inspect for ten minutes: tagging, routing, extracting fields, normalizing text, quick lookups, and small scripted edits. It is not the right place to save credits on a task whose failure will be hard to detect.

Claude Mythos 5: not a public recommendation

Mythos 5 is the same underlying model family as Fable 5 with different safeguards for selected cybersecurity work. Anthropic says access is invitation-only through trusted programs. It is not a generally selectable model, so it should not appear in a normal recommendation list. Anthropic’s Fable and Mythos announcement confirms that status.

Which Claude model to use by work type

Writing and editing

Start with Sonnet 5 at medium effort for drafts, rewrites, summaries, briefs, and ordinary long-form work. Move to high effort when the source set is large or the argument needs a stronger structure. Use Opus 5 for high-stakes editorial judgment, conflicting constraints, or a final review where missed claims matter. Fable can be worth testing for unusually long creative or document programs, but its premium is hard to justify for a single article.

Research and synthesis

Use Sonnet 5 with Research or web search for most desk research. Move to Opus 5 when sources conflict, the evidence is technical, or the answer depends on separating fact from inference. Use Fable only when the research is agentic and long-running. Model choice does not make Claude current by itself. Freshness comes from the web search tool or the paid-plan Research feature.

Data, spreadsheets, and file creation

Use Sonnet 5 for cleaning data, writing formulas, generating routine charts, and producing a first spreadsheet or deck. Use Opus 5 when the file contains interdependent formulas, a financial model, an audit trail, or a decision that needs numerical checking. Claude’s ability to execute code and create Excel, PowerPoint, Word, and PDF files is a product capability, not an Opus-only feature. Anthropic says file creation and code execution are available from Free through Enterprise, subject to organization controls.

Quick lookups, extraction, and classification

Use Haiku 4.5 when the expected answer is short, the schema is clear, and mistakes are easy to catch. That includes support-ticket routing, metadata extraction, document labeling, simple transformations, and bulk first-pass review. Use Sonnet when the categories overlap or the input requires interpretation.

Agentic multi-step work

Use Opus 5 at high or xhigh effort for a task that must plan, use tools, recover from errors, and verify its own work. Use Fable 5 when that loop may run for hours or days across a large codebase or research program. Use Sonnet 5 at medium or high when the plan is already clear and the remaining work is execution.

For coding, the surface matters as much as the model

The best Claude model for coding is not a model-only decision. Claude Code can inspect a repository, run commands, edit files, test changes, and carry context through an agent loop. A stronger model in a plain chat window can still lose to a cheaper model inside the right coding surface.

Anthropic’s own Claude Code model guide gives a useful baseline: Sonnet is right for the large majority of coding work, Opus is for difficult debugging, architecture, and large refactors, and Haiku is for quick edits or high-volume runs. It also recommends a hybrid pattern: plan with Opus, then execute with Sonnet without clearing the conversation.

• Routine implementation, tests, and bounded bugs: Sonnet 5 at medium or high.
• Architecture, unfamiliar systems, cross-cutting refactors, and stubborn bugs: Opus 5 at high or xhigh.
• Large migrations, codebase audits, and long autonomous sessions: Fable 5, but only with explicit tests and checkpoints.
• Small edits, routing, and repetitive scripted work: Haiku 4.5.

The model does not remove the need for verification. Early user reports on r/Anthropic include false completion claims, while other users report stronger self-checking. That split is a warning against judging a coding model from one clean demo.

Effort is a separate choice

Model and effort are separate controls. Anthropic currently exposes effort on Fable 5, Opus 5, Sonnet 5, Opus 4.8, Opus 4.7, Opus 4.6, and Sonnet 4.6. Low and medium are intended for routine work and longer usage. High is the default balance of quality and speed. Xhigh is aimed at long-running coding and agentic tasks, while max spends the most reasoning budget. Higher effort takes longer and consumes limits faster.

This changes the recommendation shape. Sonnet 5 at medium is not the same product decision as Sonnet 5 at xhigh. Nor is Opus 5 at low the same as Opus 5 at max. Anthropic’s model selection guide says effort can be a better cost-and-latency lever than switching models.

Use this escalation order:

1. Start Sonnet 5 at medium for a clear, inspectable task.
2. Raise Sonnet to high if the first failure is missing depth rather than missing access to tools or context.
3. Move to Opus 5 at high when the task needs better judgment, planning, or error recovery.
4. Use xhigh or max only when the task is long-running enough to justify the extra token use.
5. Move to Fable only after a representative test shows it reduces rework on that workflow.

This is a decision rule, not a benchmark claim. A user-run comparison on LinkedIn found that the lower per-token model was sometimes more expensive per completed task because it used more output and took more passes. The sample is not a controlled study, but it identifies the right unit of comparison: completed, verified work.

What users report that pricing pages miss

The community evidence is user-reported, not measured performance. It is also early: Opus 5 launched two days before this guide was updated. The threads reviewed are useful for failure modes and workarounds, not market-wide conclusions.

Consensus: model names alone do not predict cost per task. Users repeatedly distinguish token price from the number of steps, retries, and verification passes a workflow consumes. That appears in discussions of Sonnet 5’s task cost, effort-related usage burn, and an Opus-versus-Sonnet discovery task.

The split: some Fable users report better planning, fewer hasty conclusions, and more caught dependencies. Others prefer Opus 5 because it is faster, cheaper per token, and close enough in capability. The disagreement shows up in first impressions of Opus 5 versus Fable, Fable comparisons in r/ClaudeCode, and public practitioner posts on planning with Fable and executing with Opus.

The recurring workaround: users split the workflow. They plan or audit with a stronger model, execute with Sonnet or Opus, route small tasks through Haiku, and switch models mid-session instead of restarting. Anthropic now documents a similar Opus-plan and Sonnet-execute pattern in Claude Code.

The omission: the runtime often matters more than the label. Tools, repository access, compaction, retries, and verification can change the result. A public LinkedIn discussion of Fable’s agent loop makes that argument directly. Treat it as practitioner interpretation, not a vendor-confirmed measurement.

Cross-subreddit check: a current r/ChatGPTCoding comparison splits heavily on limits, persistent project context, and verification loops, while a recent r/LocalLLaMA thread includes the same stage-with-Fable, execute-with-Sonnet workaround. These are practitioner reports, not a representative survey.

Claude does not generate images

No Claude model generates photos or illustrations in the way an image model does. Choosing Fable, Opus, Sonnet, or Haiku does not change that. Anthropic states this directly.

Claude can still produce visual work. It can analyze uploaded images, search for web images on supported models, build HTML or SVG diagrams and charts, create editable files and presentations, and use the separate Claude Design surface on eligible paid plans. Those are product tools and output formats, not latent image generation. The right answer to best Claude model for image generation is therefore none.

Do not confuse model features with product features

• Model-dependent: reasoning quality, speed, API price, context window, maximum output, effort support, and some tool compatibility.
• Product-level: Claude Code, Cowork, Research, code execution, file creation, projects, connectors, and Design. Availability is primarily controlled by plan, surface, and organization settings.
• Mixed: web search is a product tool, but Anthropic maintains a supported-model list. Current support includes Opus 5, Sonnet 5, Fable 5, Opus 4.8, Opus 4.7, Sonnet 4.6, Opus 4.6, and Haiku 4.5.

This distinction explains why changing model sometimes does nothing. If the task needs live sources, a repository, Python execution, or an editable spreadsheet, first choose the surface and enable the tool. Then choose the model that can reason over the result.

Plans, pricing, and usage limits

Anthropic’s live US pricing page lists Free at $0, Pro at $20 monthly or $200 annually, Max 5x at $100 monthly, Max 20x at $200 monthly, Team standard at $25 monthly or $20 per seat per month annually, and Team premium at $125 monthly or $100 per seat per month annually. Self-serve Enterprise starts at $20 per seat plus usage billed at API rates.

The plan changes access more than it changes the recommendation. Free defaults to Sonnet 5. Pro adds more models and Claude Code, but Fable runs on usage credits. Max makes Opus 5 the default and includes Fable within the separate 50-percent weekly cap. Team and Enterprise availability can vary by seat type and administrator controls.

Anthropic does not publish one simple message count because usage depends on model, effort, conversation length, attached context, tool use, and current capacity. Claude and Claude Code also share plan limits when signed in with the same subscription. The hard practical rule is that higher effort and longer conversations consume the allowance faster. Anthropic’s limits guide explains the variables.

What to do with More models and legacy options

The chat picker has a More models entry, and Enterprise administrators can hide models or effort levels. Claude Code’s current documented selector supports ten model entries:

• Opus 5: claude-opus-5
• Sonnet 5: claude-sonnet-5
• Fable 5: claude-fable-5
• Opus 4.8: claude-opus-4-8
• Opus 4.7: claude-opus-4-7
• Sonnet 4.6: claude-sonnet-4-6
• Opus 4.6: claude-opus-4-6
• Opus 4.5: claude-opus-4-5-20251101
• Haiku 4.5: claude-haiku-4-5-20251001
• Sonnet 4.5: claude-sonnet-4-5-20250929

Anthropic’s Claude Code configuration page is the live source for that list. Claude Code is included with Pro, Max, Team, and Enterprise, but the supported list is not a promise that every account will see every entry. Fable has separate credit rules, and Enterprise administrators can disable models. The in-product picker or the Claude Code model command remains the source of truth for your account.

Legacy API pricing is currently $5 per million input tokens and $25 per million output tokens for Opus 4.5 through 4.8, and $3 and $15 for Sonnet 4.5 and 4.6. Legacy models still have three defensible uses: regression testing, migration work, and reproducing a behavior that a production workflow depends on. They are not a secret value tier. Anthropic has a formal deprecation schedule, and older entries eventually retire. New work should start on the current four-model lineup unless a test proves a legacy dependency.

The practical escalation rule

Start with Sonnet 5 at medium effort. Move to high if the answer lacks depth. Move to Opus 5 when the problem itself is ambiguous or the cost of a wrong answer is high. Use Fable 5 only when the work remains difficult across a long agent run and a representative test shows less rework. Use Haiku 4.5 when you can define the output tightly and verify it cheaply.

The top model is not automatically wasteful, but it should buy something you can name: fewer retries, better planning, stronger verification, or continuity across a long task. If you cannot name the failure Sonnet is avoiding, stay on Sonnet.