text model comparison
Claude Mythos 5.2 vs Claude Opus 5.5
Claude Mythos 5.2 and Claude Opus 5.5 are both current text models, from Anthropic. Claude Opus 5.5 is 50% cheaper per 1M input tokens than Claude Mythos 5.2, $4 vs $8. In Anthropic's Claude Fable 5.2 launch table, Claude Mythos 5.2 scores 75.3% on Terminal-Bench-Science 0.1 and Claude Opus 5.5 58.7%. Both accept 1,000,000 tokens of context.
- Lower price per 1M input tokens
- Claude Opus 5.5$4 against $8
- Newer release
- Claude Mythos 5.2Nov 2026 against Sep 2026
Data verified November 10, 2026 · Dataset 2026-11-10
Side by side
Claude Mythos 5.2 and Claude Opus 5.5, 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 5.2 | Claude Opus 5.5 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $8 | $4 (better) |
| Price per 1M output tokens | $40 | $20 (better) |
| Independent benchmarks | ||
| Arena Text | Not measured | 1506 Elo (#4 of 53) |
| Arena WebDev | Not measured | 1818 Elo (#1 of 48) |
| GPQA Diamond | Not measured | 90.6% (#27 of 43) |
| FrontierMath Tiers 1-3 (v2) | Not measured | 91.2% (#4 of 43) |
| SimpleQA Verified | Not measured | 72.2% (#6 of 40) |
| Specs | ||
| Provider | Anthropic | Anthropic |
| Release date | November 9, 2026 | September 22, 2026 |
| Access | limited access | API only |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Input | text, image | text, image |
| Output | text | text |
No independent benchmark has scored both models yet. Each rank counts the current models scored on that benchmark.
Provider results
What the labs report
Results tables a lab published with one of its models, where it lists both Claude Mythos 5.2 and Claude Opus 5.5. These are the lab's own figures, not independent measurements, and each table is read on its own: labs run benchmarks with different harnesses and budgets.
Anthropic, Claude Fable 5.2 launch table, November 9, 2026Anthropic · 2026-11-10
| Benchmark | Claude Mythos 5.2 | Claude Opus 5.5 |
|---|---|---|
| Terminal-Bench-Science 0.1 | 75.3% (better) | 58.7% |
Anthropic's table from the Claude Fable 5.2 and Mythos 5.2 announcement, each model at its highest available effort, with Anthropic's safeguards on; competitor figures come from their developers' system cards or the benchmarks' leaderboards. On FrontierCode 2.0 Fable 5.2 and 5.1 ran at xhigh effort and Gemini 4 Carbon at medium. Anthropic gives a Mythos 5.2 score for Terminal-Bench-Science only. Left out here: Anthropic's own evaluations (CVE Rediscovery, de novo binder design, RoboDojo Sim), Irregular's CyScenarioBench, where each lab's score covers different tasks, and Artificial Analysis's AA-Briefcase.
Charts
Against every current text model
Where Claude Mythos 5.2 and Claude Opus 5.5 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
Only Claude Opus 5.5 has a current Arena Text score: #4 of 53. Each bar is the share of current models it beats.
Independent benchmarks
Arena Text
Claude Mythos 5.2: Not scored
Claude Opus 5.5:#4of 53
1,506 Elo · ahead of 94%
Arena WebDev
Claude Mythos 5.2: Not scored
Claude Opus 5.5:#1of 48
1,818 Elo · ahead of 100%
GPQA Diamond
Claude Mythos 5.2: Not scored
Claude Opus 5.5:#27of 43
90.6% · ahead of 38%
FrontierMath Tiers 1-3 (v2)
Claude Mythos 5.2: Not scored
Claude Opus 5.5:#4of 43
91.2% · ahead of 93%
SimpleQA Verified
Claude Mythos 5.2: Not scored
Claude Opus 5.5:#6of 40
72.2% · ahead of 87%
Price and context
Price per 1M input tokens
Claude Mythos 5.2:#53of 61
$8 · cheaper than 12%
Claude Opus 5.5:#47of 61
$4 · cheaper than 20%
Price per 1M output tokens
Claude Mythos 5.2:#53of 61
$40 · cheaper than 12%
Claude Opus 5.5:#47of 61
$20 · cheaper than 20%
Context window
Claude Mythos 5.2:#28of 70
1M tokens · longer than 23%
Claude Opus 5.5:#28of 70
1M tokens · longer than 23%
Quality against price
Claude Opus 5.5 scores 1,506 at $8 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.
Quality against price: the data
| Model | Provider | Blended price per 1M tokens | Arena Text (Elo) |
|---|---|---|---|
| Gemini 4 Carbon | $4 | 1,526 | |
| Gemini 4 Argon | $4 | 1,522 | |
| Muse Wonder | Meta | $8 | 1,511 |
| Claude Opus 5.5 | Anthropic | $8 | 1,506 |
| Claude Fable 5 | Anthropic | $20 | 1,504 |
| Claude Fable 5.1 | Anthropic | $20 | 1,503 |
| Gemini 3.8 Flash | $1.50 | 1,497 | |
| Muse Spark 1.3 | Meta | $2 | 1,496 |
| Claude Opus 5 | Anthropic | $10 | 1,490 |
| Kimi K3 | Moonshot Kimi | $6 | 1,487 |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,484 |
| Gemini 3.6 Flash | $3 | 1,483 | |
| GLM-5.3 | Z.ai | $2.15 | 1,483 |
| Claude Opus 4.8 | Anthropic | $10 | 1,482 |
| GPT-6.1 Sol | OpenAI | $4 | 1,482 |
| GPT-5.5 | OpenAI | $11 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,475 |
| GPT-6 Astra | OpenAI | $20 | 1,474 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,474 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,468 |
| Grok 4.5 | xAI | $3 | 1,466 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,464 |
| Claude Sonnet 5 | Anthropic | $4 | 1,461 |
| GPT-6 Sol | OpenAI | $4 | 1,457 |
| Grok 4.6 | xAI | $3 | 1,456 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,455 | |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,453 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,448 |
| Step 5 Preview | StepFun | $1.43 | 1,448 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| Grok 4.7 | xAI | $3 | 1,442 |
| GPT-6 Luna | OpenAI | $0.20 | 1,441 |
| Mistral Large 4 | Mistral AI | $1.05 | 1,423 |
| Claude Haiku 5.5 | Anthropic | $0.20 | 1,422 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Inkling 2 Small | Thinking Machines Lab | $0.47 | 1,412 |
| Solar Pro 4 | Upstage | $0.52 | 1,387 |
| GPT-4.1 mini | OpenAI | $0.70 | 1,383 |
| GPT-4.1 nano | OpenAI | $0.18 | 1,322 |
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, Claude Mythos 5.2 costs 2.0 times as much as Claude Opus 5.5, at each provider's listed rates.
10M input and 2M output tokens
Claude Mythos 5.2 costs 2.0× as much
- Claude Mythos 5.2
- $160
- Claude Opus 5.5
- $80
The same, with 9M of the input tokens cached
Claude Mythos 5.2 costs 2.0× as much
- Claude Mythos 5.2
- $89.80
- Claude Opus 5.5
- $45.80
The same, through the batch API
Claude Mythos 5.2 costs 2.0× as much
- Claude Mythos 5.2
- $80
- Claude Opus 5.5
- $40
| Workload or rate | Claude Mythos 5.2 | Claude Opus 5.5 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $160 | $80 (better) |
| The same, with 9M of the input tokens cached | $89.80 | $45.80 (better) |
| The same, through the batch API | $80 | $40 (better) |
| Other listed rates | ||
| 1M input tokens, cached | $0.20 | $0.20 |
| 1M input tokens, 5-minute cache write | $10 | $5 (better) |
| 1M input tokens, 1-hour cache write | $16 | $8 (better) |
| 1M input tokens, batch | $4 | $2 (better) |
| 1M output tokens, batch | $20 | $10 (better) |
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 5.2
Where it leads
No measured lead over Claude Opus 5.5 in this data.
Best for
- Vetted security teams finding, reproducing and fixing vulnerabilities
- Dual-use research in security or biology that Claude Fable 5.2's safeguards block
Watch out for
- Limited access: only organisations verified through Anthropic's programs, such as the Cyber Verification Program, can call it
- No independent benchmark has scored it; every number for it comes from Anthropic
Claude Opus 5.5
Where it leads
- Lower input and output prices, $4 and $20 vs $8 and $40 per 1M tokens
- Cheaper batch processing, $40 vs $80 for 10M input and 2M output tokens
Best for
- Long-running agentic coding and knowledge work as the general-purpose default
- Cache-heavy agent loops where the 0.05x read multiplier compounds
Watch out for
- The API effort default is medium here, not high as on Claude Fable 5.1 and Claude Sonnet 5.5, so a like-for-like comparison has to set effort explicitly
- The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates do not compare directly across generations
From benchmark to production
Building on Claude Mythos 5.2 or Claude Opus 5.5?
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 5.2 vs Claude Opus 5.5 FAQ
Which is cheaper, Claude Mythos 5.2 or Claude Opus 5.5?
Claude Opus 5.5 is 50% cheaper per 1M input tokens than Claude Mythos 5.2, $4 vs $8. For 10M input and 2M output tokens, Claude Mythos 5.2 costs $160 and Claude Opus 5.5 $80 at standard rates.
Which is cheaper with prompt caching, Claude Mythos 5.2 or Claude Opus 5.5?
Claude Mythos 5.2 charges $0.20 per 1M cached input tokens, 98% below its standard input rate, and Claude Opus 5.5 $0.20, 95% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Mythos 5.2 costs $89.80 and Claude Opus 5.5 $45.80.
How do Claude Mythos 5.2 and Claude Opus 5.5 compare in Anthropic's own results?
In the Claude Fable 5.2 launch table (November 9, 2026), Claude Mythos 5.2 leads on Terminal-Bench-Science 0.1, 75.3% to 58.7%. These are Anthropic's figures, not independent measurements.
Which has the larger context window, Claude Mythos 5.2 or Claude Opus 5.5?
Both accept 1,000,000 tokens of context. Both return up to 128,000 tokens per response.
Further reading
More on Claude Mythos 5.2 and Claude Opus 5.5
Articles on Claude Mythos 5.2 and Claude Opus 5.5
- Claude Fable 5.2 vs Opus 5.5, GPT-6 Astra and Mythos 5.2November 10, 2026 · compares both
- GDPval-AA Chart Fact-Check: Opus 5.5 vs GPT-6 Astra on CostSeptember 24, 2026
- GPT-6 Sol vs Claude Opus 5.5, Plus Luna: Best Value per TaskSeptember 24, 2026
- Claude Opus 5.5 Benchmarks: What the Chart Shows and HidesSeptember 23, 2026
- Claude Opus 5.5: Tops the Independent Index at a Lower PriceSeptember 23, 2026
Related comparisons
- Claude Fable 5.1 vs Claude Mythos 5.2
- Claude Haiku 5.5 vs Claude Opus 5.5
- Claude Fable 5.2 vs Claude Mythos 5.2
- Claude Opus 5.5 vs Gemini 4 Argon
- Claude Fable 5 vs Claude Mythos 5.2
- Claude Opus 5.5 vs GPT-6.1 Sol
- Claude Mythos 5.1 vs Claude Mythos 5.2
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Mythos 5.2 vs Gemini 4 Carbon
- Claude Fable 5 vs Claude Opus 5.5
- Claude Mythos 5.2 vs GPT-5.6 Cyber
- Claude Opus 4.8 vs Claude Opus 5.5
Production evaluation
Choosing between Claude Mythos 5.2 and Claude Opus 5.5?
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