tokevenClaude Mythos 5.1 vs Claude Opus 5.5
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
Claude Mythos 5.1
FlagshipClaude Opus 5.5
FlagshipQuality
Task confidence comparison
Guidance
When to use Claude Mythos 5.1 vs Claude Opus 5.5
Choose Claude Mythos 5.1 when...
- Similar performance; consider provider preference or ecosystem fit.
Choose Claude Opus 5.5 when...
- -Cost matters: 60% cheaper on input tokens
At scale
Cost at scale
FAQ
When should I use Claude Mythos 5.1 instead of Claude Opus 5.5?
Claude Mythos 5.1 and Claude Opus 5.5 perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is Claude Opus 5.5 cheaper than Claude Mythos 5.1?
Yes. Claude Opus 5.5 input costs $4.00/MTok vs $10.00/MTok for Claude Mythos 5.1, saving 60% on input.
What are the context window sizes for Claude Mythos 5.1 and Claude Opus 5.5?
Claude Mythos 5.1 has a 1,000K token context window. Claude Opus 5.5 has a 1,000K token context window.
Go deeper on either model
Per-call cost calculators, provider lineups, and price history for both models on this page.
Other comparisons
How Claude Mythos 5.1 and Claude Opus 5.5 stack up against the rest of the field.
Track your real costs
Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.