Claude Mythos 5.1 vs Claude Opus 5
Pricing verdict: Claude Mythos 5.1 vs Claude Opus 5: Claude Opus 5 is cheaper for input-heavy usage ($5.00/M vs $10.00/M input tokens), while Claude Mythos 5.1 is better for long-context tasks (1,000,000 tokens).
Direct answer: choose Claude Opus 5 for lower token spend and choose Claude Mythos 5.1 when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Claude Mythos 5.1
Claude Opus 5
Cost Differences
Claude Opus 5 costs less than Claude Mythos 5.1
Quick Recommendation
Winner for direct API pricing: Claude Opus 5. At the default workload, Claude Opus 5 saves about $52.50/month ($638.75/year) versus Claude Mythos 5.1.
Feature Comparison
| Feature | Claude Mythos 5.1 | Claude Opus 5 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Input Price | $10.00/1M tokens | $5.00/1M tokens |
| Output Price | $50.00/1M tokens | $25.00/1M tokens |
| Context Window | 1,000,000 tokens | 1,000,000 tokens |
| Max Output | 128,000 tokens | 128,000 tokens |
| Category | flagship | flagship |
| Capabilities | textvisionreasoningcode | textvisionreasoningcode |
| Release Date | 9/1/2026 | 7/24/2026 |
Claude Mythos 5.1 vs Claude Opus 5: Which Should You Choose?
Choosing between Claude Mythos 5.1 and Claude Opus 5 depends on your priorities: cost efficiency, context length, or raw capability. Claude Opus 5 is the more affordable option at $5.00/1M input tokens — 50% cheaper than Claude Mythos 5.1.
Both models are in the flagship category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Claude Opus 5 would save you roughly $5,250.00/month compared to Claude Mythos 5.1. For startups and indie developers, that difference can be significant.
Output costs matter too. Claude Mythos 5.1 charges $50.00/1M output tokens vs $25.00 for Claude Opus 5. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Claude Opus 5 has the edge here at $25.00/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose Claude Mythos 5.1 when:
- • You're already using Anthropic's API ecosystem
Choose Claude Opus 5 when:
- • Budget is a primary concern
- • You're already using Anthropic's API ecosystem
Pros and Caveats at a Glance
Claude Mythos 5.1
- • Input pricing: $10.00/M tokens
- • Output pricing: $50.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Higher input cost than Claude Opus 5
- • Higher output cost than Claude Opus 5
Claude Opus 5
- • Input pricing: $5.00/M tokens
- • Output pricing: $25.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Mythos 5.1 (Anthropic)
Claude Opus 5 (Anthropic)
Start using Claude Mythos 5.1 today
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Sign Up for Anthropic →Frequently Asked Questions
Which is cheaper, Claude Mythos 5.1 or Claude Opus 5?▼
What is the context window difference between Claude Mythos 5.1 and Claude Opus 5?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
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