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Claude Mythos 5.1 vs Claude Mythos 5

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

Claude Mythos 5.1 Cost
$20.00
Claude Mythos 5 Cost
$20.00
Same cost at this usage
FeatureClaude Mythos 5.1Claude Mythos 5
ProviderAnthropicAnthropic
Input Price (1M)$10.00$10.00
Output Price (1M)$50.00$50.00
Context Window1,000,0001,000,000

Verdict

Claude Mythos 5.1 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. Claude Mythos 5 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. Claude Mythos 5.1 and Claude Mythos 5 have identical input token pricing. For output tokens, Claude Mythos 5.1 is the more affordable option at $50.00/1M vs $50.00.

On context window, Claude Mythos 5.1 supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.

When to choose Claude Mythos 5.1

  • ✓ You are already integrated with Anthropic

When to choose Claude Mythos 5

  • ✓ You are already integrated with Anthropic

Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.

Frequently Asked Questions

Is Claude Mythos 5.1 cheaper than Claude Mythos 5?

Claude Mythos 5.1 and Claude Mythos 5 have identical input token pricing at $10.00/1M tokens.

What is the context window of Claude Mythos 5.1 vs Claude Mythos 5?

Claude Mythos 5.1 has a 1,000,000-token context window. Claude Mythos 5 has a 1,000,000-token context window. Claude Mythos 5.1 supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: Claude Mythos 5.1 or Claude Mythos 5?

The best choice depends on your use case. For cost efficiency on input tokens, Claude Mythos 5.1 is the cheaper option. For maximum context length, Claude Mythos 5.1 supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.