Claude Fable 5 vs Claude Mythos 5
Claude Fable 5 and Claude Mythos 5 share the same Mythos-class architecture, but they are not interchangeable products. At launch, Fable 5 was the general Claude route for production teams, while Mythos 5 was invite-only through Project Glasswing for approved cybersecurity defenders and biomedical researchers. Anthropic has since suspended both routes while it works to restore access, so this page separates launch capability evidence from current availability.
Do not pick either Claude Fable 5 or Claude Mythos 5 for new production work while access remains unavailable. When access returns, pick Fable 5 for normal production adoption across Claude API, Bedrock, Vertex AI, and Microsoft Foundry at the tracked $10/M input and $50/M output launch price. Track Mythos 5 only if you are eligible for Project Glasswing or a trusted access program. Do not attribute Mythos 5 starred benchmark scores, including Terminal-Bench 2.1 88.0% and HLE with-tools 64.5%, to Fable 5.
Decision scorecard
Local evidence first| Signal | Claude Fable 5 | Claude Mythos 5 |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 1m |
| Cheapest output | $50/1M tokens | $50/1M tokens |
| Provider routes | 8 tracked | 3 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Claude Fable 5 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Claude Fable 5 for Coding, RAG, and Agents.
- Claude Mythos 5 uniquely exposes Code execution in local model data.
- Local decision data tags Claude Mythos 5 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Fable 5
$20,500
Cheapest tracked route/tier: Anthropic
Claude Mythos 5
$20,500
Cheapest tracked route/tier: Anthropic
Estimated monthly gap: $0.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
- Claude Mythos 5 adds Code execution in local capability data.
- Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
- Check replacement coverage for Code execution before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-09 | 2026-06-09 |
| Context window | 1m | 1m |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Claude Fable 5 | Claude Mythos 5 |
|---|---|---|
| Input price | $10/1M tokens | $10/1M tokens |
| Output price | $50/1M tokens | $50/1M tokens |
| Providers |
Capabilities
| Capability | Claude Fable 5 | Claude Mythos 5 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Continue comparing
Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.