On June 10, 2026, Anthropic officially released two new large models, Claude Fable 5 and Claude Mythos 5. The two share the underlying architecture, targeting both general users and specific research and security institutions. They have significantly surpassed their predecessors and competitors such as GPT 5.5 and Gemini 3.1 Pro in multiple authoritative benchmark tests, while relying on differentiated security strategies to achieve a balance between capabilities and risks (Source: Anthropic's official account on social media platform X, June 10, 2026). This iteration not only refreshes the performance limit of the model, but also establishes a new paradigm for AI security control in the industry.
Two model positioning: Same origin kernel, targeting different usage scenarios
Claude Fable 5 and Claude Mythos 5 are developed based on the same underlying model, with the core difference being the level of security protection and external access permissions.
| dimension | Fable 5 | Mythos 5 |
|---|---|---|
| positioning | Mythos level model fully open to ordinary users worldwide | Targeted opening, limited to partners, security agencies, and research teams only |
| scene | Enterprise office, software development, visual analysis, comprehensive reasoning | Network security, biological research, zero day vulnerability mining |
| safety | Equipped with an intelligent classifier, high-risk scenarios are automatically downgraded to Opus 4.8 | No additional security restrictions, retaining all native capabilities |
| price | $10 per million input tokens/$50 per million output tokens | Same as above (unified pricing, half of the previous generation Mythos Preview) |
Product ranking: Mythos 5>Fable 5>Claude Opus 4.8>Other mid-range versions
Benchmark score: Leading mainstream AI models in multiple dimensions
The Claude 5 series consistently ranks first in over ten authoritative evaluations, including coding, vision, inference, and network security, with a particularly prominent advantage in long cycle complex tasks.
The biggest highlight of the Claude 5 series is not a single round of Q&A, but the processing of long cycle complex tasks. The larger the task volume, the more obvious the gap with competitors, "said Zhou Hang, Chief Analyst of the AI evaluation agency IMC. (Source: 36Kr, June 10, 2026)
Test case: This model can complete the migration of 50 million lines of Ruby code within 1 day, while manual completion of the same workload usually takes two months.
Security architecture design: Fable 5 dynamic risk control, guarding the bottom line of applications
Claude Fable 5 is equipped with a new intelligent classifier that sets up dynamic interception and model degradation mechanisms for high-risk areas, achieving a balance between openness and security risks.
Protection objects: two high-risk scenarios of network security and biochemistry
Trigger mechanism: System recognizes sensitive requests → automatically intercepts instructions → seamlessly switches to Claude Opus 4.8 response (Source: Anthropic Official Announcement, June 10, 2026)
Mythos 5 has not been equipped with any safety barriers and retains all its capabilities. This model has repeatedly discovered high-risk zero day vulnerabilities in mainstream operating systems and browsers, and its powerful attack and defense capabilities have become the core reason for its restrictions on external openness.
Anthropic Security Director Emma Taylor explained at the press conference:
"We split the model into two versions in order to distinguish the target audience, allowing ordinary users to enjoy high performance and professional institutions to use full capabilities, while minimizing the risk of abuse"
In the testing of biological and network security with star markers, there was a significant difference between the two models - Fable 5 showed a decline in performance due to security restrictions, while Mythos 5 maintained a high score, which intuitively reflects the ability difference brought by security mechanisms.
Core competency breakdown: covering general scenarios and cutting-edge scientific research
The Claude 5 series covers four core areas of software development, visual analysis, life sciences, and network security, balancing civilian productivity with cutting-edge scientific research value.
4.1Software Development and Automation
The model has end-to-end coding capability, which not only enables code writing and bug fixing, but also supports complete code library refactoring and project migration. Relying on a high benchmark coding system, it can independently undertake enterprise level engineering projects, significantly reducing research and development labor costs. Currently, multiple overseas technology companies have integrated it into their internal research and development processes.
4.2 Visual Understanding and Content Restoration
Support multimodal tasks such as complex chart analysis, reverse engineering of web screenshots, and autonomous game screen completion. Without the need for additional auxiliary tools, interactive tasks can be completed solely through visual images, and the depth of visual understanding surpasses that of the previous generation model.
4.3 Life Science Research
Mythos 5 performs well in protein design, genomics, drug blind testing, and other scenarios, and can shorten the cycle of new drug development and biological experiments. At present, multiple overseas biological laboratories have incorporated it into scientific research tools to promote the intelligent upgrading of the life science field.
4.4 Network Security Attack and Defense
This series of models has outstanding strength in vulnerability mining and attack and defense exercises. Mythos 5 is specifically open to security defense teams for actively investigating system vulnerabilities, becoming an important technical tool for network security protection.
Industry impact and market pattern changes
The Claude 5 series has been released, further consolidating Anthropic's advantages in enterprise level AI, coding, and professional research tracks, and rewriting the global competitive landscape of big models.
The release of Claude 5, combined with a half price pricing strategy, will further expand its market share in enterprise services and developer communities.
This model also confirms two major trends in the AI industry:
| trend | explanation |
|---|---|
| Graded openness has become mainstream | Top models will no longer be fully liberalized across the board, but will divide permissions based on user identity and usage scenarios |
| Security is no longer the opposite of ability | Technologies such as dynamic risk control and model degradation enable high-performance AI to be implemented in compliance |
Target audience and usage recommendations
| crowd | recommendation model | reason |
|---|---|---|
| Ordinary individuals, small and medium-sized enterprises, development teams | Claude Fable 5 | Balancing performance, cost, and compliance, suitable for general scenarios such as daily office work, code development, and graphic analysis. Automatically downgrade sensitive content without worrying about compliance issues |
| Network security defense agencies, biological/pharmaceutical laboratories | Claude Mythos 5 | Apply for targeted permissions, fully utilize the top capabilities of the model in the professional field, and assist in cutting-edge research and security protection |
General usage tips:
When dealing with lengthy documents, large code repositories, and multi-step complex tasks, Claude 5 maximizes its advantages and is recommended to prioritize undertaking long-term projects
Simple Q&A scenarios can be paired with lightweight models to control usage costs
