Claude Fable 5 vs Claude Mythos 5
Explore the differences in features and access for businesses.
Restricted as of July 1, 2026: Claude Mythos 5 is not generally available and is limited to Anthropic's Project Glasswing program; Claude Fable 5 is generally available worldwide. Both models share the same underlying model, released June 9, 2026. The difference is safeguards and who can get access.
Claude Fable 5 keeps its safeguards on and is open to everyone. Claude Mythos 5 has safeguards lifted for authorized defenders, so Anthropic gates it behind a restricted program. For nearly every business, the model you can deploy today is Claude Fable 5.
This page compares the two on availability, who each is for, safeguards, price, and compliance. It does not cover offensive-security techniques. It focuses on governance, access, and buying decisions.
Claude Fable 5 vs. Claude Mythos 5: Side-by-Side
| Dimension | Claude Fable 5 | Claude Mythos 5 |
|---|---|---|
| Availability | Generally available worldwide as of July 1, 2026 | Not generally available; restricted to Project Glasswing partners |
| Who it is for | Any business or developer | Vetted cyberdefenders, infrastructure providers, and (planned) biomedical researchers |
| Safeguards | Safeguards on; blocks high-risk cyber and bio requests | Safeguards lifted for authorized offensive-security and research work |
| Price | $10 per million input tokens, $50 per million output | Not publicly priced; access is through the program |
| Data retention | Mandatory 30-day safety retention; full zero-retention not available | Mandatory 30-day safety retention; program-specific terms |
| Compliance surface | Standard Enterprise: SOC 2, ISO 27001, ISO 42001, HIPAA BAA | Program-specific; standard Enterprise BAA and ZDR not automatic |
| Best for | Software, knowledge work, vision, and research at scale | High-stakes technical defense work by authorized users |
Are Claude Fable 5 and Claude Mythos 5 the same model?
Yes, Claude Fable 5 and Claude Mythos 5 share the same underlying model. Both were released June 9, 2026. What changes is the safeguard layer around that shared model.
Claude Fable 5 runs with safeguards on. Claude Mythos 5 has those safeguards lifted for authorized users. So the raw capability is the same, but the guardrails and the access rules are not.
- Shared base model, released June 9, 2026.
- Fable 5: safeguards on, open access.
- Mythos 5: safeguards lifted, restricted access.
Deciding between Claude Fable 5 and Claude Mythos 5 for your team? We can map which one fits your access, safeguards, and compliance needs.
Book a ConsultationAvailability: which one can you actually get?
Claude Fable 5 is the only one you can buy and deploy today. It became generally available worldwide on July 1, 2026, after a June 12 export-control suspension was lifted by the US Commerce Department. AWS Bedrock, Google Cloud, and Microsoft Foundry are re-enabling it in stages.
Claude Mythos 5 is not generally available. Access is limited to vetted partners in Anthropic's Project Glasswing program, with a planned expansion to biomedical researchers. US organizations' access was restored June 26, 2026 after US government approval.
Who is each model for?
Claude Fable 5 is for any business or developer doing software, knowledge work, vision, or research. It is Anthropic's most capable public model for these tasks and can work autonomously for longer than earlier Claude models.
Claude Mythos 5 is for a narrow group of authorized users. That means cyberdefenders, infrastructure providers, and a planned expansion to biomedical researchers. It supports high-stakes technical work that the public Fable 5 model blocks.
- Fable 5: general business, engineering, and research teams.
- Mythos 5: vetted cyber-defense and infrastructure partners.
- Mythos 5 biomedical access is planned, not open.
Safeguards: what is blocked and what is allowed?
Claude Fable 5 blocks high-risk cyber and bio requests and falls back to Claude Opus 4.8 when it does. Anthropic reports that more than 95% of Fable 5 sessions never trigger this fallback. So most normal work runs on the full model.
Claude Mythos 5 has those safeguards lifted for authorized users, which is why access is restricted. Anthropic published a red-team assessment of its cybersecurity capabilities. This page does not cover offensive techniques; the point is governance, not method.
Price and compliance side by side
Claude Fable 5 is publicly priced at $10 per million input tokens and $50 per million output tokens. Claude Mythos 5 is not publicly priced; you get it through the program, not a price list. That alone makes Fable 5 the practical buy for most budgets.
Both carry a mandatory 30-day safety retention on business accounts, so full zero-data-retention is not available on either. Fable 5 uses the standard Enterprise surface with SOC 2, ISO 27001, ISO 42001, and a HIPAA BAA on the API and Enterprise plans. Mythos 5 ships through a restricted program, so its terms are program-specific and the usual Enterprise BAA and zero-retention terms do not automatically apply.
- Fable 5 price: $10 input / $50 output per million tokens.
- Mythos 5: not publicly priced; program access only.
- Both: mandatory 30-day safety retention.
- Fable 5: standard Enterprise BAA available; Mythos 5: not automatic.
The Verdict
For nearly every business, Claude Fable 5 is the right choice. It is generally available worldwide, publicly priced, and runs on the standard Enterprise compliance surface. Claude Mythos 5 is only an option if you are an authorized Project Glasswing partner.
Claude Mythos 5 exists for a specific, narrow need: authorized defenders who need safeguards lifted for high-stakes technical work. If that is not you, its restricted access and program-specific compliance terms make it a poor fit anyway. You would still fall back to Fable 5 for day-to-day work.
The practical takeaway is simple. Deploy Claude Fable 5 now, confirm the 30-day safety retention fits your data rules, and only pursue Claude Mythos 5 if you qualify for the program and truly need it.
Researched from primary Anthropic documentation and public regulator sources. Pricing and availability are accurate as of Jul 3, 2026 and can change — confirm current terms with each vendor before you buy.
Frequently Asked Questions
- No, Claude Mythos 5 is not generally available. Access is limited to vetted partners in Anthropic's Project Glasswing program, with a planned expansion to biomedical researchers. Most businesses should use Claude Fable 5 instead.
- Yes, Claude Fable 5 is generally available worldwide as of July 1, 2026. This followed a June 12 export-control suspension that the US Commerce Department later lifted. Cloud platforms are re-enabling it in stages.
- Yes, they share the same underlying model, released June 9, 2026. The difference is that Fable 5 keeps safeguards on while Mythos 5 has them lifted for authorized users.
- Claude Fable 5 costs $10 per million input tokens and $50 per million output tokens. Claude Mythos 5 is not publicly priced because access is through the program, not a price list.
- Claude Fable 5 inherits Anthropic SOC 2, ISO 27001, and ISO 42001, with a HIPAA BAA on the API and Enterprise plans. It carries a mandatory 30-day safety retention, so full zero-data-retention is not available on it.
- No, Claude Mythos 5 does not automatically include the standard Enterprise BAA or zero-retention terms. Because it ships through a restricted program, its compliance terms are program-specific. Business accounts still carry a mandatory 30-day safety retention.
- Claude Mythos 5 is for authorized cyberdefenders, infrastructure providers, and planned biomedical researchers who need safeguards lifted for high-stakes technical work. If you do not qualify for Project Glasswing, Claude Fable 5 is the deployable alternative.
- Most businesses should choose Claude Fable 5. It is generally available, publicly priced, and runs on the standard Enterprise compliance surface. Claude Mythos 5 is restricted to program partners and is not a general-purpose option.
Not sure which Claude model fits your compliance needs?
Book a free 30-minute AI workflow audit with Layer3 Labs. We will map Claude Fable 5 to your workflows, data rules, and budget so you deploy the right model with confidence.
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