DeepSeek V4.1-Flash: new architecture family, native vision, cheaper API
DeepSeek released V4.1-Flash on 2026-09-10, the smallest model of a new architecture family with native visual understanding; it replaced V4-Flash and V4-Flash-Vision-Exp on the API (new name `deepseek-flash`) with lower prices, capping a summer of V4 updates (V4-Flash update 07-31, V4-Pro GA 08-13, vision exp 08-21).
Key facts
- Release date per DeepSeek changelog: 2026-09-10
- Official benchmarks: GPQA Diamond 90.9, Codeforces rating 3471
- API model name `deepseek-flash`; V4-Flash and V4-Flash-Vision-Exp retired, legacy names temporarily routed
- Context window reported as 1M tokens; reported off-peak price $0.15/M input, $0.60/M output (secondary source)
- V4-Pro GA on 2026-08-13 added low/high/max thinking effort and native Responses API support; peak/off-peak pricing (off-peak = half) from 2026-08-16
- ARC Prize leaderboard: DeepSeek V4 Pro 0813 scored 61.3% on ARC-AGI-2; V4 Flash 0731 scored 61.4%
What happened
DeepSeek's API changelog records a steady cadence after the April V4 preview: 2026-07-31 V4-Flash re-post-trained (same size, results "far exceeding V4-Pro-Preview"); 2026-08-13 V4-Pro general availability with much stronger agent capabilities, three thinking-effort levels and native Responses API support (so it plugs into Codex-style harnesses), plus peak/off-peak pricing; 2026-08-21 experimental V4-Flash-Vision; and 2026-09-10 V4.1-Flash, "the smallest model in our new architecture family" with native multimodal visual understanding, designed for a higher capability ceiling, faster inference and higher throughput. DeepSeek reported GPQA Diamond 90.9 and a Codeforces rating of 3471 and cut API prices.
Why it matters
The "new architecture family" framing implies larger V4.1 models are coming. A small, cheap model posting a 3471 Codeforces rating shows how quickly frontier reasoning is being commoditized by Chinese labs.
Changelog
- 2026-09-29: created
Related events
- DeepSeek V4 preview: 1.6T-parameter open MoE running on Huawei Ascend ★★★★★
- Xiaomi releases MiMo-V2.6 Pro (1.02T MoE) and Flash under MIT license; Pro becomes the top open-weights model on Artificial Analysis ★★★★
- DeepSeek V4.1 Pro enters gray testing as reports say DeepSeek is training a 2T model and planning an 8T one on Huawei chips ★★★
Sources (3)
- officialDeepSeek API Docs changelog
- pressActivepieces: DeepSeek V4.1 Flash launch
- discussionARC Prize results
id: 2026-09-10-deepseek-v4-1-flash · updated 2026-09-29 · open in the interactive timeline