Pairwise benchmark snapshot · Aug 16, 2026
In this head-to-head showdown, Claude Sonnet 4.5 delivers higher overall intelligence and human-preferred responses (Elo 1,524 vs 1,472), while Claude Sonnet 4.5 leads in SWE-bench software engineering benchmarks (70.1%), while Seed 2.1 Turbo is more budget-friendly at $1.1/1M per 1M output tokens. Review the complete breakdown below to determine which model best fits your performance and budget requirements.
10 direct benchmark disciplines evaluated across capability, speed, and cost
Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.
ByteDance Seed 2.1 Turbo, listed on public model timelines as an Aug 10 2026 API drop.
Currently comparing Claude Sonnet 4.5 vs Seed 2.1 Turbo. Alternative family tiers available.
Δ 52 Arena Elo pts
160 tok/s
$1.1 / 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 Sonnet 4.5 | Seed 2.1 Turbo | Advantage Delta |
|---|---|---|---|
| Preference Elo | +52 | ||
| Coding Elo | +51 | ||
| LiveBench | +2.6% | ||
| SWE-bench | +6.9% | ||
| GPQA Diamond | +3.4% | ||
| Time to first token | +120 ms | ||
| Output speed | 88 tok/s | 160 tok/s | +72 tok/s |
| Input price | $0.27/1M | +$2.73/1M | |
| Output price | +$13.9/1M | ||
| Context window | +56k |
Simulate monthly production API costs in USD (US Dollar).
Seed 2.1 Turbo is estimated to save $304.05/month ($3,649/year).
Higher SWE-bench (70.1%).
Lower output list price ($1.1/1M).
Lower TTFT (120 ms).
Larger window (256k).
Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).
| Target Workload | Recommended Pick | Evaluation Rationale |
|---|---|---|
| Repo / coding agents | Claude Sonnet 4.5 | Higher SWE-bench (70.1%). |
| High-volume chat | Seed 2.1 Turbo | Lower output list price ($1.1/1M). |
| Voice / low-latency UI | Seed 2.1 Turbo | Lower TTFT (120 ms). |
| Long-document RAG | Seed 2.1 Turbo | Larger window (256k). |
| Screenshots / vision | Claude Sonnet 4.5 | Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5). |
Listed on public model timelines as an Aug 10 2026 API drop. Preview-quality story, indexable because we have a full snapshot.
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