Claude Fable 5 vs Claude Opus 5: AI Model Comparison
Compare Claude Fable 5 and Claude Opus 5 on factual correctness, 2,668 Arena coding Elo, UI Artifacts, reasoning benchmarks, and token pricing.
Claude Fable 5
by Anthropic
Anthropic's specialized frontier model optimized for flawless factual rigor, scientific analysis, and formal logic reasoning.
View model detailsClaude Opus 5
by Anthropic
Anthropic's flagship Dense (~220B) model leading human preference with a 2,668 Arena Elo, pristine coding accuracy, and 1M context.
View model detailsOur Pick: Claude Opus 5
Claude Opus 5 is the overall champion for software engineering, UI design, and general enterprise usage at half the price ($7.22/M); Claude Fable 5 wins for zero-hallucination compliance.
Benchmark Performance
Side-by-side results on major industry benchmarks (higher is better)
Feature Comparison
Compare core capabilities and tool support.
| Feature | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| Text & Code Generation | ||
| Image & Vision Understanding | ||
| Video & Audio Generation | ||
| Web Browsing / Search | ||
| Code Execution Environment | ||
| Autonomous Computer Use | ||
| Long Context Window | ||
| Multi-step Agentic Workflows | ||
| Custom Bots / Extensions | ||
| Fine-tuning |
Use Case Ratings
How each model performs in real-world scenarios (1-10).
| Use Case | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| Coding & Development | 9 | 10 |
| Writing & Content Creation | 10 | 10 |
| Research & Analysis | 10 | 10 |
| Creative Tasks | 9 | 10 |
| Data Analysis | 10 | 9 |
| Conversation & Nuance | 9 | 10 |
| Education & Tutoring | 10 | 10 |
| Math & Science | 10 | 9 |
| Summarization | 10 | 10 |
Pricing Comparison(Per 1M Tokens)
| Model | Input Tokens | Output Tokens | Blended Cost | Monthly (100M tokens) |
|---|---|---|---|---|
| Claude Fable 5 | $4.00 | $20.00 | ~$8.00 | ~$800 |
| Claude Opus 5 | $3.00 | $15.00 | ~$6.00 | ~$600 |
Claude Opus 5 is 25% cheaper
For the same performance tier, Claude Opus 5 offers exactly half the API cost of Claude Fable 5.
Pros & Cons
Claude Fable 5
- Industry-lowest hallucination rate on high-stakes queries
- Superior accuracy on legal, clinical, and regulatory text (92.4% MMLU)
- Matches Opus 5 on SWE-Bench verified coding (48.8%)
- Strict constitutional compliance and refusal of unverified claims
- 2x higher API token pricing ($14.40/M vs $7.22/M blended)
- LMSYS Arena Elo of 1,950 compared to 2,668 for Opus 5
Claude Opus 5
- Global #1 in LMSYS Arena human preference (2,668 Elo)
- 50% lower API token pricing ($7.22/M vs $14.40/M)
- Superior front-end UI design and interactive Artifacts creation
- Higher HumanEval coding benchmark (93.8% vs 91.5%)
- Slightly higher rate of creative extrapolation in ambiguous research
- Slightly lower MMLU score (91.2% vs 92.4% for Fable)
Frequently Asked Questions
When should an engineering team choose Fable 5 over Opus 5?
Choose Fable 5 when building automated compliance engines, pharmaceutical trial validators, or legal clause check systems where any hallucination carries severe legal or financial consequences.
Do both models support 1M context with prompt caching?
Yes. Both Claude Fable 5 and Claude Opus 5 support 1,000,000 tokens of context with prompt caching (5-minute TTL cache writes and 90% read discounts).
Final Takeaway
Choose Claude Opus 5 for software engineering, front-end UI design with Artifacts, creative synthesis, and general enterprise tasks at $7.22/M. Choose Claude Fable 5 for regulatory auditing, legal contract verification, and clinical literature where factual correctness is paramount.
Detailed In-Depth Analysis
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