Pairwise benchmark snapshot · Aug 17, 2026
In this head-to-head showdown, Claude Fable 5 delivers higher overall intelligence and human-preferred responses (Elo 1,616 vs 1,524), while Claude Fable 5 leads in SWE-bench software engineering benchmarks (80%), while Claude Sonnet 4.5 is more budget-friendly at $15/1M per 1M output tokens. Review the complete breakdown below to determine which model best fits your performance and budget requirements.
9 direct benchmark disciplines evaluated across capability, speed, and cost
Anthropic top-tier X-High reasoning model engineered for heavy multi-step tasks. Official API $10/$50 per 1M tokens (Claude Platform pricing, Aug 2026).
Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.
Currently comparing Claude Fable 5 vs Claude Sonnet 4.5. Alternative family tiers available.
Simulate accuracy gains vs added response time & token cost
Reasoning models “think before answering” by generating internal reasoning tokens. Higher effort improves math, coding, and logic accuracy, but increases response delay and token costs.
Δ 92 Arena Elo pts
88 tok/s
$15 / 1M output
Relative percentile scores computed across all active models in the benchmark catalog.
Comparing top Western standard models with China's leading frontier rival across 6 skill dimensions. Tap any spoke or dot to inspect.
Category wins across reasoning intelligence, generation speed, and token cost.
Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy
Generation throughput and time to first token responsiveness
Cost per million tokens and max context window length
| Benchmark | Claude Fable 5 | Claude Sonnet 4.5 | Advantage Delta |
|---|---|---|---|
| Preference Elo | +92 | ||
| Coding Elo | +91 | ||
| LiveBench | +7.8% | ||
| SWE-bench | +9.9% | ||
| GPQA Diamond | +7.4% | ||
| Time to first token | +100 ms | ||
| Output speed | 58 tok/s | 88 tok/s | +30 tok/s |
| Input price | +$7/1M | ||
| Output price | +$35/1M | ||
| Context window | — |
Simulate monthly production API costs in USD (US Dollar).
Claude Sonnet 4.5 is estimated to save $770.00/month ($9,240/year).
Higher SWE-bench (80%).
Lower output list price ($15/1M).
Lower TTFT (240 ms).
Larger window (1M).
Both accept images. Defaulting to the higher-Elo side (Claude Fable 5).
| Target Workload | Recommended Pick | Evaluation Rationale |
|---|---|---|
| Repo / coding agents | Claude Fable 5 | Higher SWE-bench (80%). |
| High-volume chat | Claude Sonnet 4.5 | Lower output list price ($15/1M). |
| Voice / low-latency UI | Claude Sonnet 4.5 | Lower TTFT (240 ms). |
| Long-document RAG | Claude Fable 5 | Larger window (1M). |
| Screenshots / vision | Claude Fable 5 | Both accept images. Defaulting to the higher-Elo side (Claude Fable 5). |
Fable 5 is Anthropic's top-tier X-High reasoning tier. Read SWE-bench and output price together.
Most of Opus 4.5 coding at a mid-tier price. Sonnet 5 replaced it as the buy; 4.5 remains a compare baseline.
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Verified Head-to-Head Telemetry
