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.
Quick Verdict
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.
Within Anthropic's flagship Claude 5 family, software engineers and enterprise architects face a crucial choice between Claude Fable 5 and Claude Opus 5. Claude Opus 5 stands as the undisputed champion of software development and human preference with a historic 2,668 LMSYS Arena rating, while Claude Fable 5 is specifically calibrated for uncompromising factual rigor and scientific compliance.
Models at a Glance
Claude Fable 5
by Anthropic
$20/month
Claude Pro
Claude Opus 5
by Anthropic
$20/month
Claude Pro
Capabilities Comparison
| Capability | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| Text Generation | ||
| Code Generation | ||
| Image Generation | ||
| Vision / Image Understanding | ||
| Video Generation | ||
| Audio / Voice Generation | ||
| Web Browsing / Search | ||
| Code Execution | ||
| Function Calling | ||
| Structured Output (JSON) | ||
| Advanced Reasoning (CoT) | ||
| File Upload & Analysis | ||
| Fine-Tuning | ||
| Plugins / Extensions | ||
| Memory / History | ||
| Agentic Capabilities | ||
| Custom Bots |
Use Case Ratings
Claude Fable 5
Claude Opus 5
Benchmark Scores
| Benchmark | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| MMLU (Knowledge) | 92.4% | 91.2% |
| MMLU-Pro | 85.0% | 83.5% |
| HumanEval (Coding) | 91.5% | 93.8% |
| GPQA (Graduate Q&A) | 73.2% | 71.4% |
| MATH (Competition) | 90.4% | 91.6% |
| GSM8K (Grade Math) | 97.2% | 97.8% |
| ARC (Reasoning) | 98.4% | 98.1% |
| HellaSwag | 97.1% | 96.9% |
| MT-Bench | 9.52 | 9.58 |
| LMSYS Arena ELO | 1950 | 2668 |
| SWE-Bench | 48.8% | 48.8% |
| AIME (Advanced Math) | 79.8% | 80.6% |
Feature-by-Feature Comparison
| Feature | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| LMSYS Arena ELO Rating | 1,950 | 2,668 (Global #1) |
| Factual Rigor & Compliance | Top Industry Benchmark | Standard Frontier |
| Blended Price / 1M Tokens | $14.40 | $7.22 (50% cheaper) |
| Frontend UI Artifacts | Standard | Optimized Artifacts Champion |
Pricing Comparison
| Plan | Claude Fable 5 | Claude Opus 5 |
|---|---|---|
| Free Version | ||
| Subscription | $20/month | $20/month |
| API Input (1M tokens) | $4.00 | $3.00 |
| API Output (1M tokens) | $20.00 | $15.00 |
Pros & Cons
Claude Fable 5
✅ Pros
- 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
❌ Cons
- 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
✅ Pros
- 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%)
❌ Cons
- Slightly higher rate of creative extrapolation in ambiguous research
- Slightly lower MMLU score (91.2% vs 92.4% for Fable)
🏆 Who Wins in Each Category?
Coding & UI Artifacts
Claude Opus 5 achieves a 2,668 Arena Elo and 93.8% HumanEval score.
Factual Non-Hallucination
Claude Fable 5 achieves 92.4% MMLU and 73.2% GPQA Diamond.
Cost Efficiency
Opus 5 costs $7.22/M compared to $14.40/M for Fable 5.
Our 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.
Try Claude Opus 5Frequently 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).
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