DeepSeek V4.1 Flash hands-on tests and comparisons

Hands-on comparison: on the same task Opus 5.5 took 20 minutes and cost $6, while DeepSeek V4.1 Flash-1017 took 60 minutes and cost $0.23 — about 26x cheaper, with a quality gap smaller than expected.

The author pushes back on claims that V4.1-Flash-1017 distilled GPT-6 Astra, arguing DeepSeek's token speed is far too fast for that.

Official release breakdown: terminal tasks 31.2→42.3, full-program tasks 20.3→29.1, software engineering 77.0, same API price, plus new Search & Fetch APIs.

The author wired DeepSeek V4.1 Flash 1017 as the brain of a Live2D character with AivisSpeech voice and a no-deliberation reply setting, getting smooth-paced conversation; the latest AITuber OnAir release supports the model.

Third-party router OrcaRouter gives free access to the latest V4.1 Flash, with 50 calls per day, rising to 800 per day after a $20 top-up.

Official numbers show gains on all 11 benchmarks: Terminal-Bench 4.0 rises from 31.2 to 42.3 and ProgramBench from 20.3 to 29.1, with a caveat that independent testing is still needed.

A developer ran the same prompt and Rust loop plan on both models and found V4.1 Flash clearly better than Haiku 5.5, possibly bringing it back into their workflow.

The author says V4.1-Flash-1017 can handle some text writing but reads noticeably AI-ish: if Gemini 4 Argon is 100 meters from Opus 5.5, 1017 is about 200 meters and GPT-6.1 Sol about 500.

A YouTube video runs a full comparison between DeepSeek V4.1 Flash 1017 and GPT-6.1 Sol, concluding it reaches the world's top tier.

With DeepSeek V4.1 Flash-1017 and DSH 0.2.1-rc.2, a single unrevised prompt produced a Three.js cruise simulator and promo clip in about an hour for $0.50 in API costs, though the top-deck windows missed the mark.

Citing V4.1's strong cost-performance, the user plans to cancel Claude Max, move to dsh and hermes harnesses, pay per use for DeepSeek Search and X/Reddit context, and run local LLMs once the server arrives.

A hands-on test has V4.1-Flash generate a video from a single-sentence prompt; weaker than Opus 5.5 but solid for a Flash model at 10M tokens for about ¥0.7.