Model Comparison
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
vs. GPT-5.5 (xhigh)
Comparing 2 AI models · 7 benchmarks · Anthropic, OpenAI
Recommended Pick
An Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) 9 metric wins Strongest on: TTFT, Latency, Reasoning
Best Value
GPT-5.5 (xhigh)
100.0 value score
66.0 reasoning / $11.25/1M
Lowest Price
GPT-5.5 (xhigh)
$5.00/1M input price
Best Reasoning
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
70.3 reasoning score
Blends available reasoning benchmarks
Best for Coding
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
62.0 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Best value
GPT-5.5 (xhigh) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GPT-5.5 (xhigh) is 2.5x cheaper on input tokens than Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback).
Speed gap
GPT-5.5 (xhigh) generates about 1.1x as many tokens per second as Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback).
Reasoning gap
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) leads GPT-5.5 (xhigh) by 4.3 points on reasoning.
Coding gap
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) leads GPT-5.5 (xhigh) by 2.9 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
Anthropic
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
GPT-5.5 (xhigh)
OpenAI
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
Full Comparison
| Metric | Top Pick An Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) | Op GPT-5.5 (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $12.50/1M | $5.00/1M |
| Output Cost | $50.00/1M | $30.00/1M |
| Blended (3:1) | $21.88/1M | $11.25/1M |
| Specifications | ||
| Organization | Anthropic | OpenAI |
| Release Date | Jun 9, 2026 | Apr 23, 2026 |
| Performance & Speed | ||
| Throughput | 55.5 tok/s | 58.5 tok/s |
| TTFT | 42331ms | 78705ms |
| Latency | 42331ms | 78705ms |
| Composite Indices | ||
| Value Score | 54.8 | 100.0 |
| Reasoning Score | 70.3 | 66.0 |
| Intelligence | 64.9 | 60.2 |
| Coding | 62.0 | 59.1 |
| Standard Benchmarks | ||
| GPQA | 92.6% | 93.5% |
| HLE | 53.3% | 44.3% |
| SciCode | 60.2% | 56.1% |
| LCR | 70.0% | 74.3% |
| IFBench | 63.5% | 75.9% |
| TAU-bench v2 | 98.5% | 93.9% |
| TerminalBench Hard | 62.9% | 60.6% |
Key Takeaways
GPT-5.5 (xhigh) offers the best value at $5.00/1M, making it ideal for high-volume applications and cost-conscious projects.
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) has the strongest reasoning profile with a 70.3 reasoning score, combining the available reasoning-heavy benchmarks.
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) reaches a 62.0 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
GPT-5.5 (xhigh)
- Cost-sensitive applications
- High-volume processing
