The cheapest serious coder against Alibaba's fast multimodal all-rounder.
DeepSeek V4 Flash and Qwen3.8 Flash are aimed at the same jobs — fast coding help and agent work that can run all day — and both hold a million tokens of context. The difference is what you pay for sight.
DeepSeek V4 Flash is a 284B-parameter mixture-of-experts model with 13B active per token, priced at $0.18 per million tokens. It takes text and code only. Qwen3.8 Flash costs $0.47 per million tokens, reads pictures and video, and is the more complete assistant when a conversation contains screenshots or frames.
At a glance
| Spec | DeepSeek V4 Flash | Qwen3.8 Flash |
|---|---|---|
| Maker | DeepSeek | Alibaba |
| Parameters | 284B | Not published |
| Active per token | 13B | — |
| Context window | 1M (750,000 words) | 1M (750,000 words) |
| Upstream price / MTok | $0.18 | $0.47 |
| Image and video input | No | Yes |
| Tool use | Yes | Yes |
| Zero data retention | Yes | No |
| License | MIT | Apache 2.0 |
| Good at | Coding and agents | Fast multimodal and agent work |
Where DeepSeek V4 Flash pulls ahead
- Text-heavy work at volume: at $0.18 per million tokens it is roughly 2.6x cheaper than Qwen3.8 Flash, which matters when you leave a coding agent running.
- Long text archives: the million-token window is the same, but DeepSeek's lower rate makes summarising very large document sets cheaper.
- Zero data retention: DeepSeek V4 Flash is listed with ZDR, while Qwen3.8 Flash is not, which matters for sensitive text.
Where Qwen3.8 Flash pulls ahead
- Screenshots, charts and UI review: Qwen3.8 Flash reads images, so you can paste a design and ask what is wrong with it.
- Video understanding: it accepts video input as well as still images, which DeepSeek V4 Flash cannot do at all.
- Multimodal agent loops: when the loop needs to inspect a rendered page or a frame, Qwen is the only one of the two that stays in the conversation.
The price difference
Qwen3.8 Flash costs $0.47 per million tokens against $0.18 for DeepSeek V4 Flash — about 2.6x more. On UsingOpen you can chat with both for free inside the daily limit, so the rate is a fair proxy for how expensive each model is to run rather than a bill you pay here. Multiply it by your monthly token volume if you are comparing API access elsewhere.
Which should you choose?
If your work is text and code, DeepSeek V4 Flash is the better deal. You give up vision and keep the million-token window, tool use and zero-retention terms, at less than half the upstream price. For a coding agent or a document pipeline, that is the obvious pick.
The moment a picture enters the conversation, the decision flips. Qwen3.8 Flash can look at a screenshot, a diagram or a video frame; DeepSeek V4 Flash cannot. Paying roughly 2.6x more for that ability is reasonable when sight is the job, and wasteful when it is not.
Chat with DeepSeek V4 Flash free · Chat with Qwen3.8 Flash free
Frequently asked questions
Do DeepSeek V4 Flash and Qwen3.8 Flash have the same context window?
Yes — both are listed with a 1M context window, roughly 750,000 words. The practical limit is therefore similar, and the decision comes down to price, modalities and behaviour.
Which of DeepSeek V4 Flash and Qwen3.8 Flash can read images?
Qwen3.8 Flash accepts image input; DeepSeek V4 Flash is text-only. If a screenshot, diagram or video frame is part of the task, only Qwen3.8 Flash can handle it.
Is DeepSeek V4 Flash or Qwen3.8 Flash better for coding?
Both are tuned for coding or agent work: DeepSeek V4 Flash for coding and agents, Qwen3.8 Flash for fast multimodal and agent work. The faster way to choose is to send the same real task to both in Compare mode and read the answers; the spec sheet cannot settle it.
Which is cheaper, DeepSeek V4 Flash or Qwen3.8 Flash?
DeepSeek V4 Flash is listed at $0.18 per million tokens against $0.47 for Qwen3.8 Flash — about 2.6x cheaper. Both are free to chat with on UsingOpen inside the daily limit when live; the rates matter if you are comparing what API access would cost.
Can I chat with DeepSeek V4 Flash and Qwen3.8 Flash for free?
Yes. Both are selectable on UsingOpen without an account when they are live, and each user gets 10 free prompts per day. A model paused for capacity is unavailable until it returns; the picker shows live status. History stays on your device, and Compare mode can send one prompt to both models side by side.
Is Qwen3.8 Flash worth the higher price over DeepSeek V4 Flash?
Only if you need image or video input. The two share a million-token context, tool support and fast inference. DeepSeek adds zero-retention terms and a much lower upstream rate; Qwen adds sight. If your prompts are text-only, the extra cost buys nothing you will use.
Which one is better for very long documents?
Both fit about 750,000 words in one conversation, so the practical limit is similar. DeepSeek V4 Flash is the cheaper way to process that much text, while Qwen3.8 Flash is better if the documents are scans, slides or screenshots that need to be read as images.
Related comparisons
- GLM 5.3 Flash vs DeepSeek V4 Flash — The site's default all-rounder against the cheapest heavy hitter.
- DeepSeek V4.1 Flash vs DeepSeek V4 Flash — DeepSeek's new multimodal Flash against the older text-only bargain.
- MiniMax M3 vs Qwen3.8 Flash — MiniMax's video-and-agent model against Qwen's faster, cheaper all-rounder.