选择 Claude 模型
入门
Anthropic 提供了一系列处于不同能力/成本/速度定位的模型。选好模型的关键在于让模型与任务匹配——并且不为你用不到的能力多花钱。
当前的模型
Last verified: 2026-11-02 · Official models & pricing
| Model | API model ID | Tier | Best for |
|---|---|---|---|
| Claude Fable 5.1 | claude-fable-5-1 | Mythos-classflagship (above Opus) | Released September 1, 2026. For demanding reasoning and long-horizon agentic work, or when Opus 5.5 at higher effort still falls short on your evals — Anthropic's models overview recommends starting with Opus 5.5 for most workloads and reaching for Fable 5.1 only when it falls short. Same list price as Fable 5 with cache reads at a quarter of the cost. Three breaking changes vs Fable 5: forced tool_choice (any/tool) returns 400, thinking blocks are readable only by Fable 5.1 or newer, and editing earlier turns invalidates thinking blocks. Refuses in-band (HTTP 200, stop_reason: refusal); fallback targets are Opus 5 and Opus 4.8. 30-day retention (not ZDR-eligible unless expressly authorized by Anthropic); not on Priority Tier. (Supersedes Claude Fable 5, now a legacy model.) |
| Claude Mythos 5.1 | claude-mythos-5-1 | Mythos-classverification required | Same capabilities, specs and pricing as Fable 5.1, available only to organizations verified through Anthropic's verification programs. Since October 6, 2026 that is an application, not an invitation: Project Glasswing was restructured into the Cyber Verification Program's three tiers — Defense Access (organizations, and individuals on paid plans), Red Team Access (organizations only) and Specialized Access (organizations only, reviewed with the US government, where Glasswing members landed) — each granting Opus 5.5, Sonnet 5.5 and Mythos 5.1. Apply at portal.anthropic.com/programs; decisions typically within seven business days. Does not run the conversation-binding check on thinking blocks. Customers without access should use Fable 5.1. |
| Claude Opus 5.5 | claude-opus-5-5 | Opusmost capable | Anthropic's recommended starting point for most workloads, released September 22, 2026: long-running agentic coding and knowledge work, 1M context, 128k output, June 2026 reliable knowledge cutoff. Beats the larger Fable 5.1 on every row of Anthropic's launch table at 40% of its list price. Default effort is 'medium' (shared only with Haiku 5.5 — every other model that supports effort defaults to 'high'), and at a given level it thinks more per turn than Opus 5 — re-run your effort sweep instead of carrying settings over. Four breaking changes vs Opus 5: thinking cannot be disabled at any effort level (400), forced tool_choice (any/tool) returns 400 including on token counting, thinking blocks are bound to both the model and the conversation prefix, and computer_20251124 is rejected on the Claude API and Google Cloud (still accepted on Bedrock). A fifth change returns 200: text between tool calls now arrives in progress-update thinking blocks, empty at the default display of 'omitted'. Refuses in-band (HTTP 200, stop_reason: refusal) with new 'bio' and 'reasoning_extraction' categories; server-side fallback does NOT retry 'reasoning_extraction'. Fast mode is Claude API only. Retirement no sooner than September 22, 2027. (Supersedes Claude Opus 5, now a legacy model.) |
| Claude Opus 5 | claude-opus-5 | Opusmost capable | Legacy since September 22, 2026 (superseded by Opus 5.5) but still available. Complex agentic coding and enterprise work, 1M context, 128k output. Two reasons to stay on it for now: it accepts thinking: {type: 'disabled'} at 'high' effort or below, and its thinking blocks are readable by more models than Opus 5.5's (only Fable 5.1 and Mythos 5.1 read Opus 5.5's). (Supersedes Claude Opus 4.8, now a legacy model.) |
| Claude Sonnet 5.5 | claude-sonnet-5-5 | Sonnetbalanced | The best combination of speed and intelligence, released September 28, 2026: well-scoped everyday tasks, bug fixes, multistep tool use and polished documents, 1M context, 128k output (300k on Batches with a beta header), June 2026 reliable knowledge cutoff. Exactly Sonnet 5's prices and the same tokenizer, yet Anthropic claims output 30%+ faster and up to 30% less per task — the saving is in the token and turn counts, not the rate card. Beats Opus 5.5 on Terminal-Bench 4.0 (70.6% vs 66.4%) and ties it on knowledge-work Elo, but trails it by ~8 points on FrontierCode 1.1. Default effort is 'high' and levels are recalibrated — re-run your sweep. Minimum cacheable prompt drops to 512 tokens (1,024 on Sonnet 5). Five breaking changes vs Sonnet 5: thinking: {type: 'disabled'} returns 400 (use 'between_tools', accepted only at 'high' effort or below and with no companion field), forced tool_choice (any/tool) returns 400 including on token counting, thinking blocks are bound to the model, the conversation prefix and the producing account, computer_20251124 is rejected on the Claude API and Google Cloud (still accepted on Bedrock), and Opus 4.8 / Opus 4.7 / Sonnet 5 are rejected as advisor-tool advisors. A sixth change returns 200: text between tool calls arrives in progress-update thinking blocks, empty at the default display of 'omitted'. Refuses in-band (HTTP 200, stop_reason: refusal) in five categories; server-side fallback retries only 'cyber' and 'frontier_llm', on Sonnet 5. temperature/top_p/top_k at non-default values return 400. Retirement no sooner than September 28, 2027. (Supersedes Claude Sonnet 5, now a legacy model.) |
| Claude Sonnet 5 | claude-sonnet-5 | Sonnetbalanced | Legacy since September 28, 2026 (superseded by Sonnet 5.5) but still available. The balanced pick when speed and cost matter more than Opus-level depth, 1M context. Two reasons to stay on it for now: it accepts thinking: {type: 'disabled'} at any effort level including 'xhigh' and 'max' (Sonnet 5.5's 'between_tools' tops out at 'high'), and it supports forced tool_choice, which Sonnet 5.5 does not. It is also the server-side fallback target for Sonnet 5.5's 'cyber' and 'frontier_llm' refusals. (Supersedes Claude Sonnet 4.6, now a legacy model.) |
| Claude Haiku 5.5 | claude-haiku-5-5 | Haikufastest & cheapest | The fastest model, released October 7, 2026: high-volume, latency-sensitive work — classification, extraction, routing, and cheap sub-agents. 1M context (up from Haiku 4.5's 200k), 128k output (up from 64k, 300k on Batches with a beta header), June 2026 reliable knowledge cutoff (up from Feb 2025), and the first Haiku with adaptive thinking and the effort parameter (default 'medium'). THE ONLY CURRENT MODEL PRICED BY PROMPT LENGTH: every other 4.6-and-later model bills the full 1M window at standard rates, but Haiku 5.5 has two rate cards split at 100,000 tokens, and crossing that line reprices the WHOLE request — input, output, cache writes, cache reads and batch — at 5x. It also moves to the newer tokenizer, so the same text counts ~30% more tokens than on Haiku 4.5: the real saving is ~87% below the cliff and ~35% above it, not the 90% on the rate card. Five breaking changes vs Haiku 4.5: budget_tokens thinking returns 400, non-default temperature/top_p/top_k return 400, assistant prefill returns 400 even with thinking off, computer_20250124 is rejected on the Claude API and Google Cloud, and sending thinking blocks back after editing earlier turns returns 400. Unusually permissive where the bigger 5.5 models are not — it accepts both thinking: {type: 'disabled'} (at 'high' effort or below) and forced tool_choice, which Opus 5.5 and Sonnet 5.5 both reject. Refuses in-band (HTTP 200, stop_reason: refusal) in four categories with NO server-side fallback. Priority Tier is not supported. Retirement no sooner than October 7, 2027. (Supersedes Claude Haiku 4.5, now a legacy model.) |
| Claude Haiku 4.5 | claude-haiku-4-5-20251001 | Haikufastest & cheapest | Legacy since October 7, 2026 (superseded by Haiku 5.5) but still available, and still the only model with a 200k context window (not 1M), a 64k output cap, and no support for the effort parameter; its reliable knowledge cutoff is Feb 2025. Three reasons to stay on it for now: it accepts assistant prefill and manual extended thinking (budget_tokens), both of which Haiku 5.5 rejects with a 400, and it supports Priority Tier, which Haiku 5.5 does not. It is also flat-rated — Haiku 5.5's cheaper price applies only to prompts up to 100,000 tokens. Watch its lifecycle closely: its earliest-possible retirement date of October 15, 2026 has now PASSED, so it can be deprecated at any time — yet as of November 2, 2026 the status table still lists it Active with no deprecation announced. It is the only current model past its floor (Opus 4.5 is next, on November 24, 2026) and it now has a direct successor. This is a signal to plan, not an outage: Anthropic commits to at least 60 days' notice once a deprecation is announced, so a migration started now has room. |
| Claude Fable 5 | claude-fable-5 | Mythos-classflagship (above Opus) | Legacy since September 1, 2026 (superseded by Fable 5.1) but still available. Multiday autonomous runs, first-shot on ambiguous specs, dense vision, sustained delegation to parallel subagents. GA June 9 2026. Refuses in-band (HTTP 200, stop_reason: refusal) — configure server-side or client-side fallback. Adaptive thinking only; raw thinking never returned. 30-day retention (NOT ZDR-eligible). Two reasons to stay on it for now: it supports forced tool_choice and Priority Tier (existing commitments only — new ones are no longer sold), which Fable 5.1 does not. |
| Claude Mythos 5 | claude-mythos-5 | Mythos-classverification required, legacy | Superseded by Mythos 5.1. Shares Fable 5's specs and pricing, offered separately for defensive cybersecurity workflows to organizations verified through Anthropic's verification programs — originally the invite-only Project Glasswing. Since October 6, 2026 the way in is an application to the Cyber Verification Program, and what its tiers grant is Mythos 5.1, not this model. Customers without access should use Fable 5.1. |
Model IDs are exact; tiers and 'best for' are guidance. Pricing, context-window sizes and rate limits change frequently and are intentionally NOT listed here — always read them on the official page above. This file is the single source of truth: never hard-code model facts in prose, link to this table instead.
试一试：哪个模型合适？
回答三个问题，获得一个起步建议：
模型选择
任务难度
最看重什么
请求量
Recommended
Claude Sonnet
均衡的默认之选——以 Opus 的零头成本提供强劲的推理和编码能力。先从这里起步，只有真正撞到质量天花板时再往上升。
在以下位置查询确切的模型 ID： 模型表. 仅为经验法则——用你自己的输入快速跑一次评测才能确定。
心智模型：一条能力阶梯
- 从 Sonnet 开始。 它是默认的主力——具备强大的推理与编码能力，且成本合理。大多数任务都应从这里起步。
- 仅在 Sonnet 力不从心、且质量比成本更重要时（高难度推理、棘手的智能体、棘手的代码）才升级到 Opus。
- 对于高并发、对延迟敏感或简单的工作（分类、抽取、路由、廉价的子智能体），降级到 Haiku。
实际该如何选择
- 默认使用 Sonnet 并上线。
- 遇到质量瓶颈？ 只在困难的子集上尝试 Opus。
- 成本或延迟吃不消？ 看看 Haiku 是否足以胜任那一步。
- 混合使用模型。 用 Haiku 做廉价的前/后处理，用 Sonnet/Opus 攻克核心难题。这种"模型分层"是最有力的成本杠杆之一——参见 成本与延迟。
不要只凭基准测试来选
公开的基准测试是一个起点提示，而不是针对 你的 任务的定论。在两个模型上，用你的少量真实输入跑一个小型 评测——只需几分钟，胜过靠猜。
查找确切的模型 ID
始终传入当前的 API 模型 ID（例如在你的 messages.create 调用中）。从 上面的模型表 或官方模型页面获取它——并且最好从配置中读取，而不是在多处硬编码，这样模型升级就只需改一行。