Claude has three flagship models in 2026: Opus 4.7, Sonnet 4.6, and Haiku 4.5. All three share the same training philosophy (Constitutional AI) and a 1M token long context, but they differ clearly in reasoning depth, speed, price, and use cases. This article summarizes—based on real-world testing—the prices, performance, context window, tokenizer changes, and how to choose among the three, so you can decide which one to use within 5 minutes without reading official docs.
A quick one-table overview of the three models: core differences at a glance
Model Opus 4.7 Sonnet 4.6 Haiku 4.5 Positioning Strongest reasoning Daily workhorse Fastest, cheapest Launch time 2026/4/16 2026/2 Monitored in service 2026/3 Monitored in service Context Window 1M tokens 1M tokens 1M tokens API rate (per 1M token) $5／$25 (input／output) $3／$15 $1／$5 SWE-bench (programming) 87.6% ~80% ~65% Speed (relative) Slowest（deepest thinking） Medium Fast Special features Visual parsing resolution 3x, new tokenizer Adaptive Thinking Extremely low latency Use cases Complex multi-step code refactoring, research, strategy planning Everyday coding, content generation, customer support Large-scale classification, summarization, batch processing
Opus 4.7: strongest reasoning, but pay attention to tokenizer changes
Opus 4.7 is Anthropic’s flagship model released on April 16, 2026, and currently the strongest reasoning engine in the Claude series. Compared with the previous-generation Opus 4.6, the main upgrades in 4.7 include: visual parsing resolution increased 3x (more precise for reading images, interpreting screenshots, and parsing charts in PDFs), stricter instruction following (internally called “instruction adherence” by Anthropic—more rule-bound code rather than freeform), and SWE-bench programming benchmark score of 87.6%.
But Opus 4.7 introduces a new tokenizer. With the same Traditional Chinese text, the number of tokens it splits into is 37% to 47% higher than Opus 4.6. Although the official pricing remains unchanged at input $5／output $25, because the “same text consumes more tokens,” enterprise-validated bills will rise by 37% to 47%. Traditional Chinese users who are cost-sensitive should take special care: before switching from Opus 4.6 to 4.7, it’s recommended to first run a token-calibrated benchmark using your real prompts, then decide whether to migrate.
Opus 4.7 is well-suited for scenarios like complex multi-step code restructuring, legal/medical document analysis that requires strict compliance, long-document research and integrated reports, and strategy planning that demands extremely high accuracy. If it’s just daily chatting or simple coding tasks, Opus 4.7’s compute is wasted.
Sonnet 4.6: the daily workhorse with the best balance of performance and cost
Sonnet 4.6 is an intermediate model released by Anthropic in February 2026, and also the default model most commonly used by Claude.ai subscription users (Pro, Team, Max). Its biggest feature is “Adaptive Thinking”—Claude judges the complexity of the problem, decides how many internal reasoning tokens to spend, answers quickly for simple questions, and automatically thinks deeply for complex ones.
For developers, Sonnet 4.6’s cost-to-performance ratio is usually the sweet spot: its API rate is only 60% of Opus 4.7, while reasoning quality reaches 80% or more of Opus 4.7 across most benchmark-style tests. For enterprise Claude Code users, Sonnet 4.6 is the default model; when you need stronger reasoning, switch to
/model
and route the task to Opus 4.7.
Sonnet 4.6 fits scenarios like the overwhelming majority of day-to-day work—writing articles, writing general code, automated customer support replies, long-document summarization, organizing meeting notes, and translation. If you just want Claude to “get the job done,” Sonnet 4.6 is the default answer.
Haiku 4.5: fastest, cheapest, ideal for large-scale batch tasks
Haiku 4.5 is Anthropic’s entry-level model released in March 2026, replacing the 2024 Haiku 3. Haiku 3 (claude-3-haiku-20240307) was officially retired on April 19, 2026, and any existing API calls need to be switched to Haiku 4.5.
Haiku 4.5’s core positioning is “speed and unit cost”—its API rate is only one-third of Sonnet 4.6 and one-fifth of Opus 4.7, and its reasoning speed is the fastest among the three. The trade-off is shallower reasoning depth, weaker quality for creative writing and generation, and weaker capability for complex code. SWE-bench is about 65%, clearly lower than Sonnet’s 80%.
Haiku 4.5 is suited for scenarios like batch processing large volumes of data (classification, summarization, extracting structured data), real-time customer support bots (millisecond-level responses), simple intent detection (is this message complaining or praising?), and low-cost RAG Q&A systems. If your application “runs millions of similar queries per month,” Haiku 4.5 is the right choice.
Decision tree for when to use the three models
When faced with “which one to choose,” you can quickly decide with three simple questions:
Question 1: Does your task require extremely high accuracy? (e.g., production-environment code, legal documents to send to customers, complex investment analysis) → Choose Opus 4.7.
Question 2: Will your task run more than 100k times per month? (batch classification, customer support conversations, batch summarization) → Choose Haiku 4.5 for the lowest unit cost.
Question 3: None of the above? (general daily use, coding, writing, research) → Choose Sonnet 4.6 as the default answer.
For Claude.ai subscription users, Pro/Team/Max plans allow switching among the three models; you can switch anytime using
/model
between different tasks without paying in advance to lock in a model. For API users, each model is billed independently, and Anthropic also provides an Advisor strategy: plan with Opus, execute with Sonnet—real-world performance improves and cost drops by about 12%.
Claude models vs ChatGPT, Gemini: what matters in testing
Cross-vendor comparisons usually involve too many variables. This section focuses on the one-to-one matchup between “Claude’s three models and their direct competitors”:
Claude Opus 4.7 vs OpenAI GPT-5.5 Pro: Opus wins on strict instruction adherence and long-document retention; GPT-5.5 Pro still has advantages in creative writing and open-ended generation
Claude Sonnet 4.6 vs OpenAI GPT-5.5 and Google Gemini 2.5 Pro: across most real-world tests, all three trade wins; Sonnet is often the first choice for developers when it comes to code edits and refactoring
Claude Haiku 4.5 vs OpenAI GPT-5.5-mini and Google Gemini 2.5 Flash: performance is close across the three; selection often depends on the overall ecosystem you’re in (which API you’ve already adopted and which tools your team is familiar with)
It’s important to emphasize that model benchmark scores are only for reference. What matters more is whether the model is “useful for your workflow.” The recommendation: use Sonnet 4.6 as your daily baseline; switch to Opus 4.7 for high-difficulty tasks; switch to Haiku 4.5 for batch tasks; and then adjust based on your actual experience—not just the benchmark score.
Frequently asked questions (FAQ)
How much stronger is Claude Opus 4.7 than Sonnet 4.6?
SWE-bench is about 87.6% vs 80%, a gap of roughly 8 percentage points. The day-to-day experience gap usually isn’t obvious, but in complex code refactoring, long-document strict instruction following, and research-grade analysis tasks, Opus’s advantages get amplified.
How much more does Sonnet 4.6 cost than Haiku 4.5?
Sonnet 4.6’s API rate is about 3x Haiku 4.5 (input $3 vs $1, output $15 vs $5). For heavy batch workloads (millions of queries per month), the gap widens; for typical users (thousands of queries per month), the absolute cost difference is usually < $100.
Can older Claude 3 / 3.5 / 4 series models still be used?
Older versions of Sonnet and Opus can still be specified in the API, but Anthropic has sent multiple notices about retirement timelines. Haiku 3 (claude-3-haiku-20240307) was officially retired on April 19, 2026. It’s recommended that all new projects start with the 4.x series to avoid being forced to migrate later.
Why did Opus 4.7’s tokenizer change, and why did my bill increase?
Opus 4.7 switched to a new tokenizer, and the same text (especially Traditional Chinese) gets split into more tokens, so both input and output token counts rise. Official rates are unchanged, but with more tokens, the bill increases. The difference is about 37% to 47%, depending on content type. Before switching, it’s recommended to estimate real cost using a token-calibrated benchmark.
What is Claude Mythos? Can I use it?
Mythos is Anthropic’s internal codename for a stronger model. It’s only available as a research preview to about 40 audited enterprise and national security organizations; general Claude.ai users and API users can’t access it. Anthropic publishes very limited information, and it’s not expected to open to ordinary users in the near term.
Does Claude Pro subscription have usage limits for Opus/Sonnet/Haiku?
Claude.ai Pro ( $20 per month) has usage caps for all three models: Opus has the lowest quota, while Sonnet and Haiku have higher quotas. Real usage limits will be adjusted based on load, and Anthropic will remind users when nearing the limit. Team and Max plans provide higher Opus usage; Enterprise plans can negotiate for fully unlimited usage.
Full comparison of Claude model versions in this article: how to choose Opus 4.7, Sonnet 4.6, and Haiku 4.5 first appeared on 鏈新聞 ABMedia.
