DeepSeek shipped V4.1-Flash-1017 on October 17, 2026, as an in-place upgrade to V4.1 Flash. On HiAPI the new weights are already live behind the same model ID, at the same platform price. If you are already calling deepseek-v4.1-flash, you are on 1017 now. If you are not, this post covers what the upgrade adds, what it costs, and the fastest way to get a first request through.
What changed in V4.1-Flash-1017
The upgrade touches quality, not contracts. DeepSeek kept the API model name, the pricing, and the rate limits unchanged and switched the alias to new weights.
The measurable gains are in coding:
- DeepSWE v1.1 rises from 74.2 to 77.0. DeepSWE is a benchmark for real software-engineering agents, so this is a jump in the exact workload Flash gets used for most.
- #1 open-source model on the Code Arena web-dev leaderboard. Community Arena rankings are hard to game because real users vote blind. On web development, 1017 ranks first among open-source models, ahead of Kimi K3.
Everything else callers care about stays put: 1M-token context, image input alongside text, thinking on by default, and weights released under the MIT license on Hugging Face and ModelScope. For the full parameter picture, the DeepSeek V4.1 Flash model page has the live platform details.
How to call it on HiAPI
Point your OpenAI-compatible client at HiAPI and use deepseek-v4.1-flash as the model name. Both the Responses API and Chat Completions are supported, with streaming on either one.
Chat Completions, the drop-in path if you already use the OpenAI SDK:
curl https://api.hiapi.ai/v1/chat/completions \
-H "Authorization: Bearer $HIAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "deepseek-v4.1-flash",
"messages": [
{"role": "user", "content": "Refactor this function to run in O(n) and explain the trade-offs."}
]
}'
The same request through the Responses API:
curl https://api.hiapi.ai/v1/responses \
-H "Authorization: Bearer $HIAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "deepseek-v4.1-flash",
"input": "Draft an implementation plan for adding pagination to a REST endpoint."
}'
Which one should you pick? Chat Completions when you want a zero-friction swap into an existing OpenAI-style integration. Responses when you are building agentic loops and want the reasoning items and structured turn handling it gives you. The model, the price, and the limits are identical either way, so you can move between endpoints without re-testing quality.
What it costs on HiAPI
HiAPI platform pricing for deepseek-v4.1-flash as of Oct 2026:
| Model | Input $/1M tokens | Output $/1M tokens |
|---|---|---|
| DeepSeek V4.1 Flash (this model) | $0.44 | $1.32 |
| Kimi K3 | $2.32 | $11.60 |
| DeepSeek V4 Pro | $1.50 | $4.50 |
| DeepSeek V4 Flash | $0.14 | $0.28 |
Two numbers in that table deserve a closer look.
Versus Kimi K3: Flash input is about 5x cheaper, and output about 9x cheaper. Given that 1017 just passed Kimi K3 on the Code Arena web-dev board, the cheaper model is also the stronger one for this workload as of this writing.
The cache-hit price. Reused context on HiAPI bills at $0.014 per 1M input tokens, roughly 3% of the standard input price. Agent workflows re-send the same repo files, system prompts, and conversation history on every turn, so a warm cache turns your most repetitive calls into your cheapest ones. If you run long-context coding agents, this line item matters more than the headline price.
One clarification so the numbers do not blur together: DeepSeek's official list price is $0.30 per 1M input tokens and $1.20 per 1M output tokens at peak times, with a 50% discount off-peak. That is DeepSeek's own pricing. The price you pay on HiAPI is the platform price above, which bundles access, uptime, and both endpoints behind one key. We publish this breakdown for every new model the same way, as in our Seedream 4.5 API pricing post.
When to use Flash, and when to pick something else
Use V4.1 Flash as your default coding and long-context model. The 1017 scores make it the strongest open-source option for web-dev and agentic coding right now, and the cache-hit price rewards exactly the repeat-context pattern agents produce.
Step up to DeepSeek V4 Pro when a task keeps failing on Flash after a reasonable retry or two — deeper reasoning jobs, gnarlier multi-step analysis. You pay roughly 3x the input price for that headroom, so treat it as the escalation path, not the starting point.
Use DeepSeek V4 Flash for high-volume, low-complexity work where latency and cost matter more than peak quality.
Pick Kimi K3 when its specific strengths are what your task needs and the budget is secondary. At ~5x the input price of Flash, it should earn its place per task, not by default.
FAQ
Did the model ID change with the 1017 upgrade?
No. The model remains deepseek-v4.1-flash. DeepSeek upgraded the weights in place, so existing code, prompts, and integrations keep working without any change on your side.
How is context caching billed?
Standard input is $0.44 per 1M tokens. When your prompt reuses previously cached content, the cache-hit portion bills at $0.014 per 1M tokens. Agent loops that resend the same files and history every turn benefit the most.
Can V4.1 Flash take images as input?
Yes. The model accepts text and image input and returns text. Vision support is live on HiAPI.
What are the context and output limits?
The context window is 1,048,576 tokens. The maximum output is 393,216 tokens, a figure we verified directly on the platform. Reasoning effort is adjustable across none, low, high, and max, with high as the default.
How does 1017 relate to the original V4.1 Flash?
It is the same model, upgraded in place. The alias now points at the 1017 weights, so every call to deepseek-v4.1-flash on HiAPI returns responses from the newer version.
Should I use the Responses API or Chat Completions?
Both are supported and bill at the same rate. Use Chat Completions for a drop-in fit with OpenAI-style code you already have. Use Responses when you are building agentic workflows and want its reasoning and turn-management features.
Key takeaways
- V4.1-Flash-1017 is an in-place upgrade: same model ID, same price, stronger coding. Zero migration.
- The gains are real and specific: DeepSWE 74.2 to 77.0, and #1 open-source on the Code Arena web-dev leaderboard, ahead of Kimi K3.
- On HiAPI you pay $0.44 / $1.32 per 1M input/output tokens as of Oct 2026, with cache-hit input at $0.014. Reused context is where the money is saved.
- Start with Flash, escalate to v4-pro only when Flash fails, and pick Kimi K3 per task rather than by habit.
