Two flagships: Moonshot's multimodal giant against DeepSeek's full-strength V4.
Kimi K3 and DeepSeek V4 Pro are the heavyweights of the catalog, both built for the hardest coding and agent work and both holding a million tokens. The difference is scale, sight and price.
Kimi K3 is a 2.8-trillion-parameter model that reads text, pictures and video, priced at $8.50 per million tokens. DeepSeek V4 Pro is a 1.7-trillion-parameter text model at $1.98. Both support tools and zero data retention, so the decision comes down to whether you need vision and how much you will pay for the largest model available.
At a glance
| Spec | Kimi K3 | DeepSeek V4 Pro |
|---|---|---|
| Maker | Moonshot AI | DeepSeek |
| Parameters | 2.8T | 1.7T |
| Active per token | — | — |
| Context window | 1M (750,000 words) | 1M (750,000 words) |
| Upstream price / MTok | $8.50 | $1.98 |
| Image and video input | Yes | No |
| Tool use | Yes | Yes |
| Zero data retention | Yes | Yes |
| License | Modified MIT | MIT |
| Good at | Hard coding and long agent runs | Hard problems at full scale |
Where Kimi K3 pulls ahead
- The largest model on UsingOpen at 2.8T parameters, aimed at hard coding and agent runs that last a long time.
- Multimodal input: pictures and video, which DeepSeek V4 Pro cannot read.
- When the task is at the absolute top end and cost is secondary, Kimi K3 has the most capacity to throw at it.
Where DeepSeek V4 Pro pulls ahead
- Price: $1.98 versus $8.50 per million tokens, making DeepSeek V4 Pro about 4.3x cheaper.
- Text-only reasoning and coding at scale, where the extra modalities of Kimi would sit unused.
- A full-strength V4 with the same million-token window at a fraction of the cost, which is the better default for long text work.
The price difference
Kimi K3 costs $8.50 per million tokens against $1.98 for DeepSeek V4 Pro — about 4.3x 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?
Kimi K3 is the choice for the hardest problems when you need sight or the largest model in the catalog. It is the most expensive option on the site, so reserve it for work that genuinely benefits from the extra scale or from image and video input.
DeepSeek V4 Pro is the value flagship. For long text, advanced reasoning and serious coding, it offers a million-token window at less than a quarter of Kimi's price. Start here unless a picture or a top-end benchmark result pulls you upward.
Chat with Kimi K3 free · Chat with DeepSeek V4 Pro free
Frequently asked questions
Do Kimi K3 and DeepSeek V4 Pro 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 Kimi K3 and DeepSeek V4 Pro can read images?
Kimi K3 accepts image input; DeepSeek V4 Pro is text-only. If a screenshot, diagram or video frame is part of the task, only Kimi K3 can handle it.
Is Kimi K3 or DeepSeek V4 Pro better for coding?
Kimi K3 is the closer fit for code here — the catalog tunes it for hard coding and long agent runs — while DeepSeek V4 Pro is aimed at hard problems at full scale. For project-scale coding, start with Kimi K3; if the task leans toward the other model's strengths, it may still win.
Which is cheaper, Kimi K3 or DeepSeek V4 Pro?
DeepSeek V4 Pro is listed at $1.98 per million tokens against $8.50 for Kimi K3 — about 4.3x 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 Kimi K3 and DeepSeek V4 Pro 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 Kimi K3 worth more than four times the price of DeepSeek V4 Pro?
Only if you need its unique advantages: image and video input, or the largest parameter count in the catalog for the hardest tasks. Both hold a million tokens and support tools. On text-only work, paying 4.3x more needs a measurable quality gain on your own prompts.
Which has more parameters?
Kimi K3 has 2.8 trillion parameters; DeepSeek V4 Pro has 1.7 trillion. Parameter count is a rough measure of capacity, not a guarantee of quality. The better test is to run the same hard prompt through both in Compare mode.
Related comparisons
- GPT-OSS 120B vs DeepSeek V4 Flash — OpenAI's open-weight reasoner against DeepSeek's long-context bargain.
- DeepSeek V4.1 Flash vs DeepSeek V4 Flash — DeepSeek's new multimodal Flash against the older text-only bargain.
- GLM 5.3 vs GLM 5.3 Flash — Same family, opposite trade-offs: the full model is bigger; the Flash is multimodal.