Pairwise benchmark snapshot · Aug 16, 2026
This page compares Claude Opus 4.5 (Anthropic) and Seed 2.1 Turbo (ByteDance) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, Claude Opus 4.5 is ahead by 96 points (1,568 vs 1,472; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, Claude Opus 4.5 resolves 76.8% versus 63.2% (seed-bootstrap (Aug 1, 2026)). Seed 2.1 Turbo streams faster (160 tok/s) while Seed 2.1 Turbo is the cheaper output token ($2.5/1M). Seed 2.1 Turbo has the larger context window (262k tokens). Every cell below is a dated snapshot from a named public source — we do not invent missing scores, and we do not run SWE-bench ourselves.
Anthropic
Claude Opus 4.5Anthropic frontier coding and computer-use model. SWE-bench leader on the official mini-SWE-agent harness in the Feb 2026 refresh.
ByteDance
Seed 2.1 TurboByteDance Seed 2.1 Turbo, listed on public model timelines as an Aug 10 2026 API drop.
Instant pairwise benchmark recalculation across 400+ LLMs
Category wins across intelligence, speed, and pricing efficiency.
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
Each spoke is a skill. Farther from the center is better (0–100th percentile). Tap any dot to inspect details.
96 pts advantage
98 tok/s faster
$22.50/1M cheaper
Simulate monthly production API costs based on published $/1M tokens.
Seed 2.1 Turbo is estimated to save $495.00/month ($5,940/year).
Higher SWE-bench (76.8%).
Lower output list price ($2.5/1M).
Lower TTFT (120 ms).
Larger window (262k).
Both accept images. Defaulting to the higher-Elo side (Claude Opus 4.5).
| Target Workload | Recommended Pick | Evaluation Rationale |
|---|---|---|
| Repo / coding agents | Claude Opus 4.5 | Higher SWE-bench (76.8%). |
| High-volume chat | Seed 2.1 Turbo | Lower output list price ($2.5/1M). |
| Voice / low-latency UI | Seed 2.1 Turbo | Lower TTFT (120 ms). |
| Long-document RAG | Seed 2.1 Turbo | Larger window (262k). |
| Screenshots / vision | Claude Opus 4.5 | Both accept images. Defaulting to the higher-Elo side (Claude Opus 4.5). |
Listed on public model timelines as an Aug 10 2026 API drop. Preview-quality story, indexable because we have a full snapshot.
The Feb refresh made 4.5 a coding reference. Newer Opus SKUs exist; this row stays as the dated harness point.
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The real PNG is generated at /compare/claude-opus-4-5-vs-seed-2-1-turbo/opengraph-image for crawlers.
Verified head-to-head card