DeepSeek V4.1 Flash
deepseek/deepseek-v4.1-flashDeepSeek 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 output from a 552B-parameter backbone, an asymmetric split that keeps per-token compute low relative to the model's total size. Image understanding is native to the architecture, with visual and text embeddings trained jointly from the start of pre-training rather than added afterward as in the earlier experimental V4 Flash Vision Exp. It is suited for coding, terminal, and computer-use agents, along with long-horizon tasks that must run to completion across many steps and long-context analysis. Compressed KV caching cuts cache memory to roughly a quarter of the previous Flash generation, significantly reducing costs on agentic workloads. DeepSeek positions it as the cost-efficient tier of the V4.1 family and reports that it exceeds V4 Pro on performance, speed, and task completion time.
- Input price
- $0.30USD / 1M tokens
- Output price
- $1.20USD / 1M tokens
- Context window
- N/A
- Max output
- 943.7K
Try the model
Playground
Try a prompt
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Choose an example or write a prompt, then click Run.
Specifications
Pricing
- Input
- $0.30 / 1M tokens
- Output
- $1.20 / 1M tokens
- Billing formula
- usage.prompt_tokens * 0.3 / 1000000 + usage.completion_tokens * 1.2 / 1000000 + usage.cached_tokens * 0.000006 / 1000000
Context & modalities
- Max output
- 943,718 tokens
- Input
- Text
- Output
- Text
Capabilities
- Chat
- Supported
- Vision
- Not supported
- Reasoning
- Supported
- Structured output
- Supported
- Function calling
- Supported
- Audio input
- Not supported
Access
- Provider
- DeepSeek
- Model ID
- deepseek/deepseek-v4.1-flash
- Execution
- sync
- API
- Chat Completions API
- Endpoint
- /v1/chat/completions
Start building
Send your first request
OpenAI-compatible endpoint with unified authentication and usage tracking.
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
-X POST "https://api.sandbase.ai/v1/chat/completions" \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
-H "Content-Type: application/json" \
--data-binary @- <<'SANDBASE_JSON'
{
"model": "deepseek/deepseek-v4.1-flash",
"messages": [
{
"role": "user",
"content": "Hello"
}
],
"max_tokens": 2048
}
SANDBASE_JSON
)
printf '%s\n' "$result"Choose your model
Compare models
| Model | Context | Input / 1M | Output / 1M | Released |
|---|---|---|---|---|
DeepSeek: DeepSeek V4.1 FlashThis model DeepSeek | — | $0.30 | $1.20 | Sep 10, 2026 |
DeepSeek | 1M | — | — | Aug 21, 2026 |
DeepSeek | 1M | — | — | Jul 31, 2026 |
DeepSeek | 1M | — | — | Apr 24, 2026 |
DeepSeek | 1M | — | — | Apr 24, 2026 |
DeepSeek | 160K | — | — | Dec 1, 2025 |
