DeepSeek V4.1 Flash
DeepSeek | 1,048,576 token context | $0.04/M input, $0.68/M output. 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 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…DeepSeek | 1,048,576 token context | $0.04/M input, $0.68/M output. 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 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 ExpOpens in new tab. 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 ProOpens in new tab on performance, speed, and task completion time.


Captain's notes
Known for
- Asymmetric activation (8B prefill, 16B decode) cuts compute cost relative to total model size.
- KV cache footprint of ~890 bytes per token, roughly a quarter of the previous Flash generation.
- Native multimodal architecture: vision trained jointly with text from day one, not bolted on.
- Controllable reasoning effort (1–100 integer) lets you trade accuracy for inference cost.
- Designed for coding, computer-use agents, and long-horizon multi-step task completion.
Watch out for
- At 552B total parameters, running this locally demands serious hardware; most users will hit the API.
- The CED architecture is new and largely untested in production outside DeepSeek's own benchmarks.
- Output tokens cost roughly 16× more than input tokens, so verbose completions add up quickly.
Prompts to try
Compare with
- DeepSeek Flash LatestAPI-only model1,048,576 token context · $0.04/M input, $0.68/M output
- DeepSeek V4 Flash 0731Open-weights model1,048,576 token context · $0.01/M input, $1.28/M output
- DeepSeek V4 Flash 0423Open-weights model1,048,576 token context · $0.09/M input, $0.18/M output
- DeepSeek V4 Pro 0813Open-weights model1,048,576 token context · $1.32/M input, $3.96/M output
Questions people ask
- Are the weights open and can I run DeepSeek V4.1 Flash locally?
- Yes, weights are published on Hugging Face under deepseek-ai/DeepSeek-V4.1-Flash. With 552B total parameters you will need substantial hardware to run it locally; most people will use the API instead.
- What does DeepSeek V4.1 Flash cost and what is its context window?
- The API is priced at $0.04 per million input tokens and $0.63 per million output tokens, with a context window of 1,048,576 tokens (roughly one million).
- How does V4.1 Flash differ from the rest of the V4.1 family?
- V4.1 Flash is the cost-efficient tier, using the new CED architecture to keep active parameters low and compress KV cache aggressively; DeepSeek reports it exceeds V4 Pro on performance, speed, and task completion despite the lower per-token cost.
Captain's verdictA genuinely novel architecture that earns its 'Flash' label: cheap per token, built for agents, and open if you have the hardware.
Show detailed breakdown
- 1Start at the floor.Why 7,000° and not zero: the scale runs from 0° to 9,999°, and the part below 7,000° is reserved for models no source reports on yet, which carry a stand-in number there so the lists stay complete and never outrank a model with data. 7,000° is where measured data begins. A model with real data but almost no downloads sits here; everything that follows is measurement, and the room above the floor holds ten tenfold steps in downloads at 300° each. The floor is the same for every model, so it decides nothing; the degrees above it do.7,000°running total
- 2Add the downloads.11,955,246 download-equivalents in all, from OpenRouter tokens. Ten times the downloads adds the same 300°, so size matters but never runs away with the score.+2,124°9,124°running total
- 3Add the adoption rate.About 516,730 downloads a day right now, measured between two readings, at a quarter of the weight.+428°9,552°running total
- =The heat score.Where this model stands on every list of this site. Nothing else adjusts it.9,552°
- Heat score
- One number for how much a model is used and wanted right now, from 0° to 9,999°. Every list on this site that says hottest is sorted by it and nothing else.
- Floor
- The 7,000° every model with real data starts from. The scale runs from 0° to 9,999°; the part below the floor is reserved for stand-ins (models without data), so that a model with data always ranks above one without. The floor is the same for everyone and decides nothing; the degrees above it are the measurement.
- Download-equivalents
- Everything the score treats as a download, added up: downloads themselves, each torrent seeder as 1,000, each AI Horde image and each run on a generation site as one.
- Log scale
- Counting by tens, not by ones: going from 1,000 to 10,000 downloads adds the same degrees as going from 10,000 to 100,000. It keeps giants from crowding out everything else.
- Likes
- Thumbs up and likes from every source, worth half a download each on the log scale.
- Adoption rate
- How many downloads a day a model gets right now, from the difference between two readings of a source. A quarter of the weight of the download term.
- Measured and estimated
- Measured means two readings of a source exist and the difference is real. Estimated means only today's total is known and the past is spread over the model's life; the site says which one it is showing.
- Seeder
- Someone who keeps a copy of the weights online for others to download over a torrent, or a hosted mirror doing the same. Each one counts as 1,000 downloads.
- AI Horde
- A volunteer network that generates images for free on donated computers. The number of images it has made with a model is public, and each counts as one download.
- Generation sites
- Sites that host their own copies of a model and let people generate with it, such as PixAI, SeaArt and Yodayo. Their downloads count like Civitai's and each generation run as one download.
- OpenRouter tokens
- A text model served through an API, such as Claude or GPT, has no weights to download, so its usage is measured in tokens: the pieces of text it read and wrote through OpenRouter, a gateway many apps use, over the last 30 days. Every 10,000,000 tokens count as one download. Source: OpenRouter (openrouter.ai/rankings), CC BY 4.0.
- Full model (checkpoint)
- The weights themselves, the file that generates on its own. It gets a bonus because add-ons depend on it.
- LoRA and embedding
- Small add-on files that steer someone else's weights toward a style, a character or a concept. They cannot run alone.
- Family and weights
- The base a model is built on, such as SD 1.5, SDXL, Flux or Wan. Every model inherits the release date of its family's weights.
- Age
- Degrees taken off for how long ago the family's weights came out: 150° a year, up to 750°. It keeps old downloads that had years to pile up from freezing the top of the list.
- Family boost
- A small, bounded nudge for LoRAs of a family this site is pushing forward right now, always listed in the breakdown.
- Stand-in score
- A stable number below the floor given to a model no source reports on yet, so lists stay complete. It never ranks above a model with data.
- New! (grace period)
- A model less than 7 days old shows New! instead of a score and holds no place in the rankings. Its score is computed from day one, but a model one day old grows faster than anything, so without the wait the week's #1 would always be whatever came out yesterday rather than what held up for a week.
- Trend
- How a model's growth over a period compares with the typical model's growth over the same period. Faster than typical reads as a rise, slower as a fall.
- Typical model
- The middle of the catalog: half the models with a figure grew faster over the period, half slower.
