Model comparison
Claude Mythos 5.1 vs Claude Haiku 4.5
Compare Claude Mythos 5.1 vs Claude Haiku 4.5 API pricing: input/output token costs, cache pricing, context windows, workload estimates, and routing fit.
Claude Mythos 5.1
anthropic · claude-mythos-5-1
- Input
- $10
- Output
- $50
- Context
- 1M
Claude Haiku 4.5
anthropic · claude-haiku-4-5
- Input
- $1
- Output
- $5
- Context
- 200K
Quick take
Claude Haiku 4.5 has the lower input price at $1 per 1M input tokens. Claude Haiku 4.5 is cheaper for the example blended workload below. Claude Mythos 5.1 has the larger context window at 1M tokens.
Choose Claude Mythos 5.1 if...
- Claude Mythos 5.1 is safer for long documents, repository analysis, and RAG prompts because it has the larger context window.
- Claude Mythos 5.1 gives more room for long generated answers, reports, or code output.
Choose Claude Haiku 4.5 if...
- Claude Haiku 4.5 is the better default for cost-sensitive traffic and repeated high-volume calls.
Example workload cost
Estimates use input tokens plus 20% output tokens. They exclude provider discounts, cache hits, and tool/search surcharges.
| Workload | Claude Mythos 5.1 | Claude Haiku 4.5 | Cheaper |
|---|---|---|---|
| 1M input + 200K output | $20.00 | $2.00 | Claude Haiku 4.5 |
| 10M input + 2M output | $200.00 | $20.00 | Claude Haiku 4.5 |
| 100M input + 20M output | $2,000.00 | $200.00 | Claude Haiku 4.5 |
Context, output, and capability fit
Claude Mythos 5.1 provides the larger context window. Check max output separately when the task needs long reports, code generation, or full-document rewrites.
- Claude Mythos 5.1 max output
- 128K
- Claude Haiku 4.5 max output
- 64K
- Claude Mythos 5.1 features
- prompt caching, function calling, vision
- Claude Haiku 4.5 features
- prompt caching, function calling, vision
Risk notes for Claude Mythos 5.1
- High output price: cap max tokens for verbose generation workloads.
Risk notes for Claude Haiku 4.5
- No major capability risk is flagged in this snapshot, but provider pages should still be verified before production routing.
Routing tags
frontierpremiumreasoningcodingagentslong-contextmultimodalcache-friendlymythos-classlimited-availabilityragfastbudgetenterprise-rag