DeepSeek V4.1 Flash hands-on tests and comparisons

Release roundup: upgraded one-sentence-to-full-project coding, web/app/API updated at the same price with open weights; the author plans to test it hands-on.

Official release: MIT-licensed open weights, with vendor-run evals showing Terminal-Bench 4.0 rising from 31.2 to 42.3 and Apex Bench from 64.6 to 72.1.

The poster says the model is live on DeepSeek's platform and open-sourced on Hugging Face, linking pricing docs and calling the test results impressive.

A reply to SipeedLab points to a GitHub TP4 recipe as the strongest four-machine ds-4.1-flash setup, suggests sparkdash screenshots for a common benchmark, and says the Chinese community widely calls the claims inflated.

A four-point take on the upgrade: shorter outputs cut inference cost, tooling optimizations target DeepSeek Harness and CodeBuddy, strong DeepSWE and Terminal-Bench scores reinforce the price-performance pitch, and same-day rollout across site, app and API drives usage.

The user argues DeepSWE has become a joke of a benchmark and manually inserted V4.1 Flash 1017 results into a CodingFleet blog screenshot.

A user says after a Claude ban they used DeepSeek V4.1 Flash with open-source OpenDesign Motion to produce a brand motion video from one prompt, calling it an Opus 5.5 alternative.

A long Japanese post analyzes performance, pricing, the 763B open weights and post-training, citing 77% DeepSWE success versus about 75% for GPT-6.1 Sol at roughly one-third the cost.

A Japanese poster suggests putting Grok Bot at the top, letting Claude Code split tasks per project, and delegating execution to Devin SWE-2 and free OpenCode models.

Despite being labeled a minor update, V4.1-Flash-1017 reportedly outperforms GPT-5.6 Sol and Opus 5 on several published agent and coding benchmarks with shorter outputs and faster completion.

Hands-on speed reaches 244 tok/s and nearly 300 at peak, faster than GPT-6.1 Sol's Ultrafast mode with intelligence near GPT-5.6 Sol; it adds built-in web research, is free on the official harness until Oct 31, and shows clear coding and 3D gains.

The author made V4.1-Flash-1017 the default in Hermes for all-day recurring tasks and research, citing off-peak pricing of $0.15 input / $0.60 output per million tokens, and plans to report actual token usage and cost per task.