Claude Mythos 5.1 vs o3 Deep Research
Pricing verdict: Claude Mythos 5.1 vs o3 Deep Research: input pricing is tied at $10.00/M, o3 Deep Research is cheaper for output-heavy usage ($40.00/M output), and Claude Mythos 5.1 is better for long-context tasks (1,000,000 tokens).
Direct answer: input pricing is tied. Choose o3 Deep Research for cheaper output 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
o3 Deep Research
Cost Differences
o3 Deep Research costs less than Claude Mythos 5.1
Quick Recommendation
Winner for direct API pricing: o3 Deep Research. At the default workload, o3 Deep Research saves about $15.00/month ($182.50/year) versus Claude Mythos 5.1.
Feature Comparison
| Feature | Claude Mythos 5.1 | o3 Deep Research |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input Price | $10.00/1M tokens | $10.00/1M tokens |
| Output Price | $50.00/1M tokens | $40.00/1M tokens |
| Context Window | 1,000,000 tokens | 200,000 tokens |
| Max Output | 128,000 tokens | 32,768 tokens |
| Category | flagship | reasoning |
| Capabilities | textvisionreasoningcode | textreasoningvisioncode |
| Release Date | 9/1/2026 | 6/26/2025 |
Claude Mythos 5.1 vs o3 Deep Research: Which Should You Choose?
Choosing between Claude Mythos 5.1 and o3 Deep Research depends on your priorities: cost efficiency, context length, or raw capability. Both models charge $10.00/1M input tokens, but o3 Deep Research is cheaper on output at $40.00/1M. Meanwhile, Claude Mythos 5.1 offers a significantly larger context window at 1,000,000 tokens vs 200,000 for o3 Deep Research.
These models come from different providers — Anthropic and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Anthropic, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Claude Mythos 5.1 is a flagship model while o3 Deep Research is reasoning. This means they're optimized for different workloads. Claude Mythos 5.1 is built for complex tasks that require deeper reasoning, while o3 Deep Research offers better value for routine operations.
Output costs matter too. Claude Mythos 5.1 charges $50.00/1M output tokens vs $40.00 for o3 Deep Research. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. o3 Deep Research has the edge here at $40.00/1M 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 need a larger context window (1,000,000 tokens)
- • You need longer outputs (up to 128,000 tokens)
- • You're already using Anthropic's API ecosystem
Choose o3 Deep Research when:
- • You're already using OpenAI'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 output cost than o3 Deep Research
o3 Deep Research
- • Input pricing: $10.00/M tokens
- • Output pricing: $40.00/M tokens
- • Context window: 200,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Smaller context window than Claude Mythos 5.1
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Mythos 5.1 (Anthropic)
o3 Deep Research (OpenAI)
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Sign Up for OpenAI →Frequently Asked Questions
Which is cheaper, Claude Mythos 5.1 or o3 Deep Research?▼
What is the context window difference between Claude Mythos 5.1 and o3 Deep Research?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare Anthropic and OpenAI API pricing beyond this model matchup?▼
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