text model comparison
Claude Mythos 5.1 vs GPT-Rosalind-6
Claude Mythos 5.1 and GPT-Rosalind-6 are both current text models, from Anthropic and OpenAI. Claude Mythos 5.1 is 33% cheaper per 1M input tokens than GPT-Rosalind-6, $10 vs $15.
- Lower price per 1M input tokens
- Claude Mythos 5.1$10 against $15
- Newer release
- GPT-Rosalind-6Oct 2026 against Sep 2026
Data verified November 5, 2026 · Dataset 2026-11-05
Side by side
Claude Mythos 5.1 and GPT-Rosalind-6, line by line
Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.
| Fact | Claude Mythos 5.1 | GPT-Rosalind-6 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $10 (better) | $15 |
| Price per 1M output tokens | $50 (better) | $75 |
| Specs | ||
| Provider | Anthropic | OpenAI |
| Release date | September 1, 2026 | October 30, 2026 |
| Access | API only | limited access |
| Context window | Not reported | Not reported |
| Max output | Not reported | Not reported |
| Input | text, image | text |
| Output | text | text |
Charts
Against every current text model
Where Claude Mythos 5.1 and GPT-Rosalind-6 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
No independent benchmark has scored either model yet, so the tiles rank their prices among the current models of their task.
Price and context
Price per 1M input tokens
Claude Mythos 5.1:#51of 55
$10 · cheaper than 2%
GPT-Rosalind-6:#55of 55
$15 · cheaper than 0%
Price per 1M output tokens
Claude Mythos 5.1:#51of 55
$50 · cheaper than 2%
GPT-Rosalind-6:#55of 55
$75 · cheaper than 0%
Cost
What each costs
Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.
The same work, priced
For 10M input and 2M output tokens, GPT-Rosalind-6 costs 1.5 times as much as Claude Mythos 5.1, at each provider's listed rates.
10M input and 2M output tokens
GPT-Rosalind-6 costs 1.5× as much
- Claude Mythos 5.1
- $200
- GPT-Rosalind-6
- $300
The same, with 9M of the input tokens cached
GPT-Rosalind-6 costs 1.6× as much
- Claude Mythos 5.1
- $112.25
- GPT-Rosalind-6
- $178.50
| Workload or rate | Claude Mythos 5.1 | GPT-Rosalind-6 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $200 (better) | $300 |
| The same, with 9M of the input tokens cached | $112.25 (better) | $178.50 |
| Other listed rates | ||
| 1M input tokens, cached | $0.25 (better) | $1.50 |
Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.
Launch price $100, regular price $150
Verdict
When to choose each
Claude Mythos 5.1
Where it leads
- Lower input and output prices, $10 and $50 vs $15 and $75 per 1M tokens
- Accepts image input
- Cheaper cached input, $0.25 vs $1.50 per 1M tokens
Best for
- Organisations already admitted to Anthropic’s limited-availability programme that need frontier capability at Fable 5.1 rates
Watch out for
- Limited availability: access is restricted to organisations vetted through Anthropic’s Glasswing programme, so it cannot be assumed available for a general evaluation
- Anthropic’s public model comparison table does not list a context window or maximum output for Mythos 5.1, so both are recorded as unknown here rather than inferred from Fable 5.1
GPT-Rosalind-6
Where it leads
No measured lead over Claude Mythos 5.1 in this data.
Best for
- Drug discovery and life sciences research teams approved for OpenAI's trusted access
- Dual-use biology research that GPT-6 Astra is more likely to refuse
Watch out for
- Limited access: OpenAI offers it only through its trusted-access program, after reviewing each applicant's intended use, security controls and governance, for internal research
- OpenAI treats it as High capability in the biological and chemical domain, so access comes with security, monitoring and enforcement terms
- OpenAI publishes no context window for it and compares it only with GPT-Rosalind-5.5; no independent benchmark score is recorded here yet
From benchmark to production
Building on Claude Mythos 5.1 or GPT-Rosalind-6?
Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.
AI Model Cost AuditLaunch price $100, regular price $150What the audit includes
FAQ
Claude Mythos 5.1 vs GPT-Rosalind-6 FAQ
Which is cheaper, Claude Mythos 5.1 or GPT-Rosalind-6?
Claude Mythos 5.1 is 33% cheaper per 1M input tokens than GPT-Rosalind-6, $10 vs $15. For 10M input and 2M output tokens, Claude Mythos 5.1 costs $200 and GPT-Rosalind-6 $300 at standard rates.
Which is cheaper with prompt caching, Claude Mythos 5.1 or GPT-Rosalind-6?
Claude Mythos 5.1 charges $0.25 per 1M cached input tokens, 98% below its standard input rate, and GPT-Rosalind-6 $1.50, 90% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Mythos 5.1 costs $112.25 and GPT-Rosalind-6 $178.50.
How do Claude Mythos 5.1 and GPT-Rosalind-6 differ in features?
Claude Mythos 5.1 takes text and image input; GPT-Rosalind-6 takes text.
Further reading
More on Claude Mythos 5.1 and GPT-Rosalind-6
Articles on Claude Mythos 5.1 and GPT-Rosalind-6
- GPT-Rosalind-6: OpenAI's Biology Model and Trusted AccessNovember 1, 2026
Related comparisons
Production evaluation
Choosing between Claude Mythos 5.1 and GPT-Rosalind-6?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty