DeepSeek V4.1 Flash hands-on tests and comparisons

A user notes that Modal now offers deepseek-v4-1-flash-1017 and calls the pricing very cheap.

A user lists their daily work stack: Opus/Sonnet on factory, Grok in Cursor Pro, DeepSeek 1017 through a domestic plan worth roughly 12x official API usage, plus occasional 6.1 Sol via a relay.

On the same eval run, DeepSeek V4.1 Flash 1017 took 32 minutes and 220K output tokens for $0.29, versus 79 seconds for GPT-6.1 Terra, 16 minutes for Opus 5.5 and 4 minutes at $1.11 for Muse Wonder.

In a model price comparison chart, DeepSeek V4.1 Flash is so cheap that it literally breaks the x-axis scale.

On the same CursorBench 4.0 board, DeepSeek V4.1 Flash 1017 Max burns 537k tokens per task versus Opus 5.5 Max's 218k, with similar step counts (187 vs 185) but $0.98 versus $13.43 in cost.

A developer says three days of round-the-clock bug hunting would have cost about $800 in DeepSeek V4.1 Flash 1017 API credits (over $6,000 on Opus), but ran locally on a dual-GB10 host at concurrency 4 and 512k context.

After Cursor shipped its Agent SDK, the author compares coding agent results: Opus 5.5 leads at 61.7 but costs $11.42 per task, while a DeepSeek V4.1 Flash setup costs just $0.39.

A Claude Code workflow uses Opus 5.5 as orchestrator and DeepSeek V4.1 Flash sub-agents running 24 in parallel on Vercel Sandbox, with the author claiming ~99% of work done by DeepSeek for about $9 (unverified).

DeepSeek's pricing page lists Search and Fetch at $0.75 per 1,000 successful requests, with server-side calls via Harness, Claude Code and Codex becoming paid on Nov 1; the retired v4-flash model names now route to V4.1-Flash-1017 at Flash pricing.

On the same one-shot GTA task, DeepSeek V4.1 Flash 1017 took 50 minutes for $0.36, Grok 4.7 took 41 minutes for $3.58, and Opus 5.5 was faster at 30 minutes; Flash is slow but very cheap.

On one task, Opus 5.5 took 30 minutes, GPT-6.1 Sol 10 minutes, Grok 4.7 41 minutes for $3.58, while DeepSeek V4.1 Flash 1017 took 50 minutes, 257K output tokens, for $0.36.

Hands-on: Opus 5.5 orchestrates while deepseek-v4.1-flash-1017 runs sub-agents in Claude Code; 24 parallel sub-agents cost roughly $9 on DeepSeek, which did 99% of the work.