Model comparison
GPT-5.5 vs Claude Mythos 5
Compare GPT-5.5 vs Claude Mythos 5 API pricing: input/output token costs, cache pricing, context windows, workload estimates, and routing fit.
GPT-5.5
openai · gpt-5.5
- Input
- $5
- Output
- $30
- Context
- 1.1M
Claude Mythos 5
anthropic · claude-mythos-5
- Input
- $10
- Output
- $50
- Context
- 1M
Quick take
GPT-5.5 has the lower input price at $5 per 1M input tokens. GPT-5.5 is cheaper for the example blended workload below. GPT-5.5 has the larger context window at 1.1M tokens.
Choose GPT-5.5 if...
- GPT-5.5 is the better default for cost-sensitive traffic and repeated high-volume calls.
- GPT-5.5 is safer for long documents, repository analysis, and RAG prompts because it has the larger context window.
Choose Claude Mythos 5 if...
- Claude Mythos 5 is a reasonable pick when its provider, latency, or integration path fits your stack better.
Example workload cost
Estimates use input tokens plus 20% output tokens. They exclude provider discounts, cache hits, and tool/search surcharges.
| Workload | GPT-5.5 | Claude Mythos 5 | Cheaper |
|---|---|---|---|
| 1M input + 200K output | $11.00 | $20.00 | GPT-5.5 |
| 10M input + 2M output | $110.00 | $200.00 | GPT-5.5 |
| 100M input + 20M output | $1,100.00 | $2,000.00 | GPT-5.5 |
Context, output, and capability fit
GPT-5.5 provides the larger context window. Check max output separately when the task needs long reports, code generation, or full-document rewrites.
- GPT-5.5 max output
- 128K
- Claude Mythos 5 max output
- 128K
- GPT-5.5 features
- prompt caching, function calling, vision
- Claude Mythos 5 features
- prompt caching, function calling, vision
Risk notes for GPT-5.5
- High output price: cap max tokens for verbose generation workloads.
Risk notes for Claude Mythos 5
- High output price: cap max tokens for verbose generation workloads.
Routing tags
frontierreasoningcodingagentslong-contextmultimodalcache-friendlyragpremiummythos-classlimited-availability