DeepSeek V4.1 Flash hands-on tests and comparisons

Same-task comparison shows Gemini 4 Argon finishing in 13 minutes for $1.2 while DeepSeek V4.1 Flash takes 50 minutes for $0.4, cheaper but nearly four times slower.

Official figures show DeepSWE at 77.0% versus Opus 5's 74.0%, but HLE at 42.6% versus 56.3%; API output is $0.6 per million tokens, $1.2 at peak hours, with data stored on Chinese servers.

User reports V4.1 Flash 1017 works well for roleplay with solid prompt reading and style adherence, though commas increase in long conversations; also asks about free OpenCode access.

A roundup of the open weights for DeepSeek-V4.1-Flash and the official 1017 production snapshot, covering architecture, benchmarks and API access.

A link roundup whose only DeepSeek line notes V4.1-Flash-1017 is faster with shorter outputs and open weights; the rest covers unrelated items.

A user's cost breakdown: with an Anthropic subscription Opus is more than twice as cheap as DeepSeek V4.1 Flash 1017, but 19x more expensive when everything goes through the API.

On the same rocket-launch scene V4.1 Flash cost $0.78 in 3 minutes versus $6.10 and 5 minutes for GPT 6.1 Sol, which the poster calls almost 8x cheaper.

A day-one roundup: DeepSWE 77.0 tops the table while HLE lags at 42.6, a real test found a P0 bug for about 0.3 yuan, MIT weights total 510GB and won't fit at home, plus new search and fetch APIs.

Scores 81.9 on BuildingBench to land in the top five, at about $3.01 per task — roughly 1/11 the cost of Fable 5.1 and 1/15 of Sonnet 5.5.

On mini_swe_v2, V4.1 Flash 1017 scores about 77% at roughly ¥1.5 per task, versus GPT-6 Astra at 75%/¥60 and Opus 5 at 74%/¥80.

A user on DeepInfra finds V4.1 Flash 1017 questionable value against a flat-rate Claude Code plan, but cheap enough for occasional use even at max thinking, making it a handy second opinion.

A video reports V4.1 Flash 1017 gained 9 points on BuildingBench to reach the top five, beating Fable 5.1 and nearly matching Sonnet 5.5.