text model comparison
Claude Fable 5.1 vs Claude Mythos 5.2
Claude Fable 5.1 and Claude Mythos 5.2 are both current text models, from Anthropic. Claude Mythos 5.2 is 20% cheaper per 1M input tokens than Claude Fable 5.1, $8 vs $10. In Anthropic's Claude Fable 5.2 launch table, Claude Fable 5.1 scores 52.6% on Terminal-Bench-Science 0.1 and Claude Mythos 5.2 75.3%. Both accept 1,000,000 tokens of context.
- Lower price per 1M input tokens
- Claude Mythos 5.2$8 against $10
- Newer release
- Claude Mythos 5.2Nov 2026 against Sep 2026
Data verified November 10, 2026 · Dataset 2026-11-10
Side by side
Claude Fable 5.1 and Claude Mythos 5.2, 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 Fable 5.1 | Claude Mythos 5.2 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $10 | $8 (better) |
| Price per 1M output tokens | $50 | $40 (better) |
| Independent benchmarks | ||
| Arena Text | 1503 Elo (#6 of 53) | Not measured |
| Arena WebDev | 1745 Elo (#5 of 48) | Not measured |
| FrontierMath Tiers 1-3 (v2) | 90.2% (#6 of 43) | Not measured |
| SimpleQA Verified | 70.8% (#7 of 40) | Not measured |
| Specs | ||
| Provider | Anthropic | Anthropic |
| Release date | September 1, 2026 | November 9, 2026 |
| Access | API only | limited access |
| 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 Fable 5.1 and Claude Mythos 5.2. 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 Fable 5.1 | Claude Mythos 5.2 |
|---|---|---|
| Terminal-Bench-Science 0.1 | 52.6% | 75.3% (better) |
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 Fable 5.1 and Claude Mythos 5.2 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
Only Claude Fable 5.1 has a current Arena Text score: #6 of 53. Each bar is the share of current models it beats.
Independent benchmarks
Arena Text
Claude Fable 5.1:#6of 53
1,503 Elo · ahead of 90%
Claude Mythos 5.2: Not scored
Arena WebDev
Claude Fable 5.1:#5of 48
1,745 Elo · ahead of 91%
Claude Mythos 5.2: Not scored
FrontierMath Tiers 1-3 (v2)
Claude Fable 5.1:#6of 43
90.2% · ahead of 88%
Claude Mythos 5.2: Not scored
SimpleQA Verified
Claude Fable 5.1:#7of 40
70.8% · ahead of 85%
Claude Mythos 5.2: Not scored
Price and context
Price per 1M input tokens
Claude Fable 5.1:#55of 61
$10 · cheaper than 5%
Claude Mythos 5.2:#53of 61
$8 · cheaper than 12%
Price per 1M output tokens
Claude Fable 5.1:#55of 61
$50 · cheaper than 5%
Claude Mythos 5.2:#53of 61
$40 · cheaper than 12%
Context window
Claude Fable 5.1:#28of 70
1M tokens · longer than 23%
Claude Mythos 5.2:#28of 70
1M tokens · longer than 23%
Quality against price
Claude Fable 5.1 scores 1,503 at $20 (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 Fable 5.1 costs 1.3 times as much as Claude Mythos 5.2, at each provider's listed rates.
10M input and 2M output tokens
Claude Fable 5.1 costs 1.3× as much
- Claude Fable 5.1
- $200
- Claude Mythos 5.2
- $160
The same, with 9M of the input tokens cached
Claude Fable 5.1 costs 1.3× as much
- Claude Fable 5.1
- $112.25
- Claude Mythos 5.2
- $89.80
The same, through the batch API
Claude Fable 5.1 costs 1.3× as much
- Claude Fable 5.1
- $100
- Claude Mythos 5.2
- $80
| Workload or rate | Claude Fable 5.1 | Claude Mythos 5.2 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $200 | $160 (better) |
| The same, with 9M of the input tokens cached | $112.25 | $89.80 (better) |
| The same, through the batch API | $100 | $80 (better) |
| Other listed rates | ||
| 1M input tokens, cached | $0.25 | $0.20 (better) |
| 1M input tokens, 5-minute cache write | $12.50 | $10 (better) |
| 1M input tokens, 1-hour cache write | $20 | $16 (better) |
| 1M input tokens, batch | $5 | $4 (better) |
| 1M output tokens, batch | $25 | $20 (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 Fable 5.1
Where it leads
No measured lead over Claude Mythos 5.2 in this data.
Best for
- Long-horizon agentic coding where a large prompt prefix is replayed across many turns
- Work where Claude Opus 5 at higher effort has already been evaluated and fell short
Watch out for
- Base input and output pricing is unchanged from Fable 5 at $10 / $50; the saving is entirely in cache reads, so a workload with little cache reuse sees no discount
- 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 are not directly comparable across generations
- Anthropic’s launch comparisons are self-reported and were not reproduced independently here
- Claude Fable 5.2 (November 9, 2026) costs less at $8 input and $40 output per 1M tokens, and Anthropic now lists Fable 5.1 among its legacy models
Claude Mythos 5.2
Where it leads
- Lower input and output prices, $8 and $40 vs $10 and $50 per 1M tokens
- Cheaper cached input, $0.20 vs $0.25 per 1M tokens
- Cheaper batch processing, $80 vs $100 for 10M input and 2M output tokens
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
From benchmark to production
Building on Claude Fable 5.1 or Claude Mythos 5.2?
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 Fable 5.1 vs Claude Mythos 5.2 FAQ
Which is cheaper, Claude Fable 5.1 or Claude Mythos 5.2?
Claude Mythos 5.2 is 20% cheaper per 1M input tokens than Claude Fable 5.1, $8 vs $10. For 10M input and 2M output tokens, Claude Fable 5.1 costs $200 and Claude Mythos 5.2 $160 at standard rates.
Which is cheaper with prompt caching, Claude Fable 5.1 or Claude Mythos 5.2?
Claude Fable 5.1 charges $0.25 per 1M cached input tokens, 98% below its standard input rate, and Claude Mythos 5.2 $0.20, 98% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Fable 5.1 costs $112.25 and Claude Mythos 5.2 $89.80.
How do Claude Fable 5.1 and Claude Mythos 5.2 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 52.6%. These are Anthropic's figures, not independent measurements.
Which has the larger context window, Claude Fable 5.1 or Claude Mythos 5.2?
Both accept 1,000,000 tokens of context. Both return up to 128,000 tokens per response.
Further reading
More on Claude Fable 5.1 and Claude Mythos 5.2
Articles on Claude Fable 5.1 and Claude Mythos 5.2
- Claude Fable 5.2 vs Opus 5.5, GPT-6 Astra and Mythos 5.2November 10, 2026
- Grok 4.7 vs Fable 5.1 vs GPT-6 Astra: Real Cost per TaskSeptember 23, 2026
- Jev vs Fable 5.1 vs GPT-6 Astra: Which Model for Which JobSeptember 22, 2026
- GPT-6 Astra vs Fable 5.1: Two Scoreboards, Two WinnersSeptember 22, 2026
- Claude Fable 5.1: Same Price, 75% Cheaper CacheSeptember 2, 2026
- Fable 5.1 vs Opus 5 vs GPT-5.6: Which to UseSeptember 1, 2026
Related comparisons
- Claude Fable 5.1 vs Gemini 4 Argon
- Claude Fable 5.2 vs Claude Mythos 5.2
- Claude Fable 5.1 vs Claude Sonnet 5.5
- Claude Fable 5 vs Claude Mythos 5.2
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Mythos 5.1 vs Claude Mythos 5.2
- Claude Fable 5.1 vs Grok 4.7
- Claude Mythos 5.2 vs Claude Opus 5.5
- Claude Fable 5.1 vs GPT-6 Astra
- Claude Mythos 5.2 vs Gemini 4 Carbon
- Claude Fable 5.1 vs Claude Opus 4.8
- Claude Mythos 5.2 vs GPT-5.6 Cyber
Production evaluation
Choosing between Claude Fable 5.1 and Claude Mythos 5.2?
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