Pairwise benchmark snapshot · Aug 16, 2026
This page compares Claude Sonnet 4.5 (Anthropic) and Qwen 2.5 Plus (Alibaba) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, Claude Sonnet 4.5 is ahead by 79 points (1,524 vs 1,445; seed-bootstrap (Aug 1, 2026)). On SWE-bench coding, Claude Sonnet 4.5 resolves 70.1% versus 59.2% (seed-bootstrap (Aug 1, 2026)). Qwen 2.5 Plus streams faster (110 tok/s) while Qwen 2.5 Plus is the cheaper output token ($1/1M). Claude Sonnet 4.5 has the larger context window (1M 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 Sonnet 4.5Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.
Alibaba
Qwen 2.5 PlusAlibaba balanced flagship API model with high-throughput general reasoning.
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.
79 pts advantage
22 tok/s faster
$14.00/1M cheaper
Simulate monthly production API costs based on published $/1M tokens.
Qwen 2.5 Plus is estimated to save $306.25/month ($3,675/year).
Higher SWE-bench (70.1%).
Lower output list price ($1/1M).
Lower TTFT (180 ms).
Larger window (1M).
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 | Qwen 2.5 Plus | Lower output list price ($1/1M). |
| Voice / low-latency UI | Qwen 2.5 Plus | Lower TTFT (180 ms). |
| Long-document RAG | Claude Sonnet 4.5 | Larger window (1M). |
| Screenshots / vision | Claude Sonnet 4.5 | Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5). |
No comments posted on this matchup yet. Be the first to share an evaluation note!
The real PNG is generated at /compare/claude-sonnet-4-5-vs-qwen-2-5-plus/opengraph-image for crawlers.
Verified head-to-head card