Pairwise benchmark snapshot · Aug 16, 2026
In this head-to-head showdown, GPT-5.6 Terra delivers higher overall intelligence and human-preferred responses (Elo 1,548 vs 1,472), while GPT-5.6 Terra leads in SWE-bench software engineering benchmarks (70.4%), 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
OpenAI 5.6 mid tier. Official API $2/$12 per 1M after the Jul 30 2026 price cut.
ByteDance Seed 2.1 Turbo, listed on public model timelines as an Aug 10 2026 API drop.
Currently comparing GPT-5.6 Terra vs Seed 2.1 Turbo. Alternative family tiers available.
Δ 76 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 | GPT-5.6 Terra | Seed 2.1 Turbo | Advantage Delta |
|---|---|---|---|
| Preference Elo | +76 | ||
| Coding Elo | +62 | ||
| LiveBench | +4.3% | ||
| SWE-bench | +7.2% | ||
| GPQA Diamond | +5.2% | ||
| Time to first token | +40 ms | ||
| Output speed | 128 tok/s | 160 tok/s | +32 tok/s |
| Input price | $0.27/1M | +$1.73/1M | |
| Output price | +$10.9/1M | ||
| Context window | +744k |
Simulate monthly production API costs in USD (US Dollar).
Seed 2.1 Turbo is estimated to save $224.05/month ($2,689/year).
Higher SWE-bench (70.4%).
Lower output list price ($1.1/1M).
Lower TTFT (120 ms).
Larger window (1M).
Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra).
| Target Workload | Recommended Pick | Evaluation Rationale |
|---|---|---|
| Repo / coding agents | GPT-5.6 Terra | Higher SWE-bench (70.4%). |
| 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 | GPT-5.6 Terra | Larger window (1M). |
| Screenshots / vision | GPT-5.6 Terra | Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra). |
Listed on public model timelines as an Aug 10 2026 API drop. Preview-quality story, indexable because we have a full snapshot.
Terra is OpenAI’s Sonnet-class invoice. Use it when Sol is too expensive and Luna is too small.
No comments posted on this matchup yet. Be the first to share an evaluation note!
Dynamic OpenGraph banner generated at /compare/gpt-5-6-terra-vs-seed-2-1-turbo/opengraph-image
Verified Head-to-Head Telemetry
