UltraGPT
DeepSeek: DeepSeek V4.1 Flash
DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder (CED) architecture. It activates 8B parameters on input and 16B on...
Intelligence overview
1.05M tok
Context window
384K tok
Max output
What DeepSeek: DeepSeek V4.1 Flash can do.
Reasoning
Extended reasoning
Works through problems step by step before answering, trading latency for accuracy on harder tasks.
Adjustable effort
Choose how much the model deliberates per request — trade speed for depth as the task demands.
Multimodal
Image understanding
Reads and reasons over images alongside text in the same prompt.
Development
Tool calling
Calls external functions mid-response, then continues reasoning from the result.
Structured output
Returns responses constrained to a JSON schema, ready to parse without cleanup.
Streaming
Streams tokens as they're generated instead of waiting on the full response.
Performance
Pay for what you use.
Every model in UltraGPT runs behind one flat subscription — this is the underlying per-token cost the catalog tracks.
$0.15 / 1M tok
$0.6 / 1M tok
Built for serious work.
Build
Generate and refactor code, with the ability to run and verify tool calls and return structured, parseable output.
Think
Works through hard problems with adjustable reasoning effort — max, high, low.
Research
Holds up to 1.05M tokens of source material in context without losing the thread.
Create
Reads images alongside a prompt to ground creative and design work in what's actually on screen.
Automate
Chains tool calls across multi-step workflows, reasoning between each one.
Ask DeepSeek: DeepSeek V4.1 Flash anything.
A preview of the real UltraGPT composer — the model you see here is the model you get.
Continues in the UltraGPT app — one login, every model.
How DeepSeek: DeepSeek V4.1 Flash stacks up.
The closest models in the catalog by provider, capability and score — real entries, pulled from the same directory.
Technical details.
Specification
- Context window
- 1.05M tokens
- Max output
- 384K tokens
- Input modalities
- Text + Image
- Output modalities
- Text
- Release date
- Sep 10, 2026
- Reasoning effort
- max, high, low
- Streaming
- Supported
- Tool calling
- Supported
- JSON mode
- Supported
Reasoning
More from DeepSeek, and everything else.
This model is one entry in the full UltraGPT catalog — browse the rest, compare pricing and context windows, or filter by capability.