text model comparison
Claude Mythos 5.1 vs GPT-6 Cyber
Claude Mythos 5.1 and GPT-6 Cyber are both current text models, from Anthropic and OpenAI. Claude Mythos 5.1 is 50% cheaper per 1M input tokens than GPT-6 Cyber, $10 vs $20.
- Lower price per 1M input tokens
- Claude Mythos 5.1$10 against $20
- Newer release
- GPT-6 CyberNov 2026 against Sep 2026
Data verified November 6, 2026 · Dataset 2026-11-06
Side by side
Claude Mythos 5.1 and GPT-6 Cyber, 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-6 Cyber |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $10 (better) | $20 |
| Price per 1M output tokens | $50 (better) | $100 |
| Specs | ||
| Provider | Anthropic | OpenAI |
| Release date | September 1, 2026 | November 5, 2026 |
| Access | API only | limited access |
| Context window | Not reported | 1,050,000 tokens |
| Max output | Not reported | 128,000 tokens |
| Input | text, image | text, image |
| Output | text | text |
Charts
Against every current text model
Where Claude Mythos 5.1 and GPT-6 Cyber 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:#52of 58
$10 · cheaper than 5%
GPT-6 Cyber:#58of 58
$20 · cheaper than 0%
Price per 1M output tokens
Claude Mythos 5.1:#52of 58
$50 · cheaper than 5%
GPT-6 Cyber:#58of 58
$100 · cheaper than 0%
Context window
Claude Mythos 5.1: Not listed
GPT-6 Cyber:#1of 67
1.05M tokens · longer than 85%
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-6 Cyber costs 2.0 times as much as Claude Mythos 5.1, at each provider's listed rates.
10M input and 2M output tokens
GPT-6 Cyber costs 2.0× as much
- Claude Mythos 5.1
- $200
- GPT-6 Cyber
- $400
The same, with 9M of the input tokens cached
GPT-6 Cyber costs 2.1× as much
- Claude Mythos 5.1
- $112.25
- GPT-6 Cyber
- $238
| Workload or rate | Claude Mythos 5.1 | GPT-6 Cyber |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $200 (better) | $400 |
| The same, with 9M of the input tokens cached | $112.25 (better) | $238 |
| Other listed rates | ||
| 1M input tokens, cached | $0.25 (better) | $2 |
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 $20 and $100 per 1M tokens
- Cheaper cached input, $0.25 vs $2 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-6 Cyber
Where it leads
No measured lead over Claude Mythos 5.1 in this data.
Best for
- Security teams approved for Daybreak Red that develop and validate exploits in authorized tests
- Vulnerability research and patch validation across large codebases such as browsers and kernels
Watch out for
- Limited access: OpenAI is rolling it out through the API and Codex to select approved Daybreak Red customers first, with identity verification, single sign-on, multi-factor authentication and API IP allowlisting
- OpenAI rates it Critical in cybersecurity under its Preparedness Framework, like GPT-6 Astra and up from High for GPT-5.6 Cyber, and adds checks that block high-risk activity against critical systems
- It does not beat GPT-6 Astra at general coding (82.95% against 83.24% on OpenAI's internal ExpertSWE), and on Irregular's FrontierCyber it solved 90 of 288 challenges against 96 for Astra; no independent benchmark score is recorded here yet
From benchmark to production
Building on Claude Mythos 5.1 or GPT-6 Cyber?
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-6 Cyber FAQ
Which is cheaper, Claude Mythos 5.1 or GPT-6 Cyber?
Claude Mythos 5.1 is 50% cheaper per 1M input tokens than GPT-6 Cyber, $10 vs $20. For 10M input and 2M output tokens, Claude Mythos 5.1 costs $200 and GPT-6 Cyber $400 at standard rates.
Which is cheaper with prompt caching, Claude Mythos 5.1 or GPT-6 Cyber?
Claude Mythos 5.1 charges $0.25 per 1M cached input tokens, 98% below its standard input rate, and GPT-6 Cyber $2, 90% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Mythos 5.1 costs $112.25 and GPT-6 Cyber $238.
Further reading
More on Claude Mythos 5.1 and GPT-6 Cyber
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Production evaluation
Choosing between Claude Mythos 5.1 and GPT-6 Cyber?
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