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Claude 3 Opus vs Claude Mythos 5.1

Pricing verdict: Claude 3 Opus vs Claude Mythos 5.1: Claude Mythos 5.1 is cheaper for input-heavy usage ($10.00/M vs $15.00/M input tokens), while Claude Mythos 5.1 is better for long-context tasks (1,000,000 tokens).

Direct answer: choose Claude Mythos 5.1 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.

Anthropic
Claude 3 Opus
vs
Anthropic
Claude Mythos 5.1

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

Claude 3 Opus

Per Request:$0.0525
Daily:$5.25
Monthly:$157.50
Yearly:$1,916.25

Claude Mythos 5.1

Per Request:$0.035
Daily:$3.50
Monthly:$105.00
Yearly:$1,277.50

Cost Differences

$0.0175
Per Request
$1.75
Daily
$52.50
Monthly
$638.75
Yearly

Claude Mythos 5.1 costs less than Claude 3 Opus

Quick Recommendation

Winner for direct API pricing: Claude Mythos 5.1. At the default workload, Claude Mythos 5.1 saves about $52.50/month ($638.75/year) versus Claude 3 Opus.

Feature Comparison

FeatureClaude 3 OpusClaude Mythos 5.1
ProviderAnthropicAnthropic
Input Price$15.00/1M tokens$10.00/1M tokens
Output Price$75.00/1M tokens$50.00/1M tokens
Context Window200,000 tokens1,000,000 tokens
Max Output4,096 tokens128,000 tokens
Categoryflagshipflagship
Capabilities
textvisionreasoning
textvisionreasoningcode
Release Date3/4/20249/1/2026

Claude 3 Opus vs Claude Mythos 5.1: Which Should You Choose?

Choosing between Claude 3 Opus and Claude Mythos 5.1 depends on your priorities: cost efficiency, context length, or raw capability. Claude Mythos 5.1 is the more affordable option at $10.00/1M input tokens — 33% cheaper than Claude 3 Opus. Meanwhile, Claude Mythos 5.1 offers a significantly larger context window at 1,000,000 tokens vs 200,000 for Claude 3 Opus.

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 Mythos 5.1 would save you roughly $5,250.00/month compared to Claude 3 Opus. For startups and indie developers, that difference can be significant.

Output costs matter too. Claude 3 Opus charges $75.00/1M output tokens vs $50.00 for Claude Mythos 5.1. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Claude Mythos 5.1 has the edge here at $50.00/1M 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 3 Opus when:

  • • You're already using Anthropic's API ecosystem

Choose Claude Mythos 5.1 when:

  • • Budget is a primary concern
  • • You need a larger context window (1,000,000 tokens)
  • • You need more capabilities (code)
  • • You need longer outputs (up to 128,000 tokens)
  • • You're already using Anthropic's API ecosystem

Pros and Caveats at a Glance

Claude 3 Opus

  • Input pricing: $15.00/M tokens
  • Output pricing: $75.00/M tokens
  • Context window: 200,000 tokens
  • Max output: 4,096 tokens

Watch out for

  • Higher input cost than Claude Mythos 5.1
  • Higher output cost than Claude Mythos 5.1
  • Smaller context window than Claude Mythos 5.1

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

  • Trade-offs are minor in this matchup.

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

Claude 3 Opus (Anthropic)

Claude Mythos 5.1 (Anthropic)

Start using Claude 3 Opus today

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Start using Claude Mythos 5.1 today

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Frequently Asked Questions

Which is cheaper, Claude 3 Opus or Claude Mythos 5.1?
Claude Mythos 5.1 is cheaper for input tokens at $10.00 per million tokens vs $15.00 for Claude 3 Opus — that's 33% savings on input costs.
What is the context window difference between Claude 3 Opus and Claude Mythos 5.1?
Claude 3 Opus supports 200,000 tokens while Claude Mythos 5.1 supports 1,000,000 tokens — a difference of 800,000 tokens in favor of Claude Mythos 5.1.
Which model is better for AI Chatbot?
Both models support text. For ai chatbot, Claude Mythos 5.1 is the lower-cost option, while Claude Mythos 5.1 offers a larger context window (1,000,000 vs 200,000 tokens). Choose Claude Mythos 5.1 for budget sensitivity or Claude Mythos 5.1 for longer context tasks.
Which model has better overall pricing for heavy usage?
At 100 requests/day with 1,000 input and 500 output tokens each, Claude 3 Opus costs about $157.50/month and Claude Mythos 5.1 costs about $105.00/month. Overall, Claude Mythos 5.1 has lower combined input + output rates ($10.00 in, $50.00 out) vs Claude 3 Opus.

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