ByteDance Seed 2.1 Pro Preview

Best for

Teams evaluating screenshot- or mockup-to-page workflows inside the ByteDance/Volcengine ecosystem

Price & access

No USD price published. Volcengine standard-mode text pricing for Seed 2.1 Pro is CNY 6.00 per 1M input and CNY 30.00 per 1M output, with prompt-cache reads at CNY 1.20 per 1M (DataLearner).

Evidence summary

Only the Arena Elo and the preview release date are directly attributable to this exact identifier. Pricing is CNY-only from a third party, context and max output are unpublished, there is no Artificial Analysis or Design Arena row, and the benchmark table belongs to the productised Seed2.1 Pro rather than the preview.

Edition status

No prior snapshot. Tracked in the September 2026 baseline.

Strengths

• Genuine image-to-interface capability: Seed2.1 generates interactive pages from floor plans, design mockups and video
• Best-in-class multimodal perception scores in its own table (BabyVision 73.7 vs 55.9 for GPT-5.5; WorldVQA 53.0 vs 34.6)
• Large Arena vote count (7,358) for a preview, so its Elo is tightly bounded
• Free to try in the Arena Code arena

Tradeoffs

• Preview identifier with no published context window, max output or USD pricing
• SWE-Atlas 35.2 on debugging trails GPT-5.5 (44.7) and Claude Opus 4.7 (38.7)
• No Artificial Analysis coverage, no Design Arena row, no SWE-bench row
• Preview and productised Seed2.1 Pro benchmarks are different builds