Model vs model
Claude Fable 5.2 vs Claude Opus 5.5
At a glance
Longer bar means the bigger number.
Open or closed · can you download the model and run it yourself?
Blended price · per 1M tokens, lower is better
Where they sit among all 46 models
Claude Opus 5.5 ranks 1st of the 42 models with an Intelligence Index. Up and to the left is smarter for less money. Hover or tap a dot for its numbers, then click it to compare that model with Claude Fable 5.2.
Which one to pick
Pick Claude Opus 5.5 if
- you want the lower bill ($8 vs $16 per 1M tokens blended)
Claude Opus 5.5’s “controversial” take on humans
We asked Claude Opus 5.5 and 13 other models the same question three times each: “What is your most controversial take about humans? Give your own honest view, not a survey of opinions, and don't hedge.” Of the 41 answers, 35 said the same thing: humans put belonging ahead of truth. Claude Opus 5.5 gave it 2 of 3 times. Claude Fable 5.2 wasn’t in that test. Read the full story.
Claude Opus 5.5
- Answer 1 · a different take“Humans are far more decent than they believe they are, and their cynicism about each other does more damage than their actual flaws.”
- Answer 2 · the common take“Most of the reasons people give for their own choices are stories invented after the fact, and humans are far worse at knowing why they do things than they believe.”
- Answer 3 · the common take“Most human "irrationality" isn't a failure of reasoning at all; people are excellent reasoners who are usually optimizing for belonging rather than truth.”
Answers exactly as the models wrote them. “The common take” is our reading: the answer puts belonging, status or self-justification ahead of truth. How we ran it
How smart is each one?
Every intelligence score we have
Out of 100, higher is better. Claude Fable 5.2 Claude Opus 5.5
Claude Fable 5.2 has no Artificial Analysis scores yet, so only our own tests compare them.
Overall
Intelligence Index
57.6
By field of work
Finance & accounting
60.7Legal
63.3Healthcare & medicine
54.7Economics
65.6Engineering
60.4Strategy & operations
63.7
Benchmarks
Factual knowledge · SimpleQA
72.2Hard reasoning · Humanity's Last Exam
61.4Competition math · OTIS Mock AIME
100Research math · FrontierMath
91.2Scientific coding · SciCode
66.9Coding in Cursor · CursorBench 4.0
57.8Mergeable code · FrontierCode 2.0
45.5Terminal tasks · Terminal-Bench 4.0
59.6Long documents · AA-LCR
84.7Uncensored · UGI
54.5
Our tests
Hallucination test · our test, higher means it made up less
99.1Claude Fable 5.2: not scored yet
Next.js coding tasks · Vercel's Next.js evals, % of tasks passed
97Claude Fable 5.2: not scored yet
The specs
| Spec | Claude Fable 5.2 | Claude Opus 5.5 |
|---|---|---|
| Input price | $8 per 1M | $4 per 1M |
| Output price | $40 per 1M | $20 per 1M |
| Cost per test task | Not tested | $5.98 |
| Context window | 1M | 1M |
| Max output | 128K | 128K |
| Accepts | Text, Image, PDF | Text, Image, PDF |
| Open weights | No | No |
| Lab | Anthropic | Anthropic |
| Released | Nov 2026 | Sep 2026 |
| Knowledge cutoff | Not published | Jun 2026 |
Blended price weighs 3 parts input to 1 part output. List prices from models.dev. Cost per test task from Artificial Analysis.
Questions
Is Claude Fable 5.2 or Claude Opus 5.5 cheaper?
Claude Opus 5.5 is cheaper. It charges $4 per 1M input tokens and $20 per 1M output tokens, against $8 and $40 for Claude Fable 5.2. Blended 3 parts input to 1 part output, that is $8 against $16 per 1M tokens.
Are Claude Fable 5.2 and Claude Opus 5.5 open source?
No. Both are closed models: the weights aren't published, so you can only use them through an API, from Anthropic or a cloud that resells them.
Which has the longer context window?
Both accept 1M tokens.
Can I compare Claude Fable 5.2 and Claude Opus 5.5 on my own prompt?
Yes. ModelCompare sends one prompt to both models at once and shows each answer side by side with what it cost. You can try it free without an account.
Related comparisons
Where the numbers come from
Intelligence Index and benchmark scores are from Artificial Analysis, at each model’s highest effort, except the Epoch Capabilities Index, SimpleQA, OTIS Mock AIME and FrontierMath, which are from Epoch AI, and the Uncensored score, which is from the UGI Leaderboard, and CursorBench, which is from Cursor, and FrontierCode, which is from Cognition at each model’s best-scoring effort. The hallucination test is ours: questions with one exact answer, fake evidence pushed against right answers and requests that tempt a model to name packages that don’t exist. Prices are list prices from models.dev. Example answers come from our own test runs. Updated November 10, 2026.