# DeepSeek vs Second Opinion

DeepSeek records 372,761,591 monthly visits with +4.3% month-over-month growth and Freemium pricing. Second Opinion records 0 monthly visits with 0% growth and Freemium pricing.

| Metric | [DeepSeek](https://openaitools.app/tool/deepseek) | [Second Opinion](https://openaitools.app/tool/second-opinion) |
| :--- | :--- | :--- |
| Website URL | https://www.deepseek.com | https://secondopinion.so |
| Categories | Large Language Models (LLMs), Open Source AI Models, AI API, AI Chatbot | AI Checker, AI API, AI Copilot, Large Language Models (LLMs) |
| Pricing Model | Freemium | Freemium |
| Monthly Visits | 372,761,591 | 0 |
| MoM Growth Rate | +4.3% | 0% |
| Primary Market | China | Global |
| Direct Visits | 291,585,405 | 0 |
| Review Score | 4.8 | 3.9 |
| Saved Count | 44 | 0 |
| Supported Platforms | Website | Website |

## DeepSeek

DeepSeek (Hangzhou DeepSeek Artificial Intelligence Co., Ltd.) is a frontier AI research organization that disrupted the global LLM market by pairing open-weight transparency with breakthrough Mixture-of-Experts (MoE) and reinforcement-learning reasoning efficiency. Following the landmark releases of DeepSeek-V3 and the peer-reviewed DeepSeek-R1 reasoning model, DeepSeek introduced the DeepSeek-V4 generation in 2026—featuring a hybrid attention architecture and a native 1-million-token context window across DeepSeek-V4-Pro (1.6T total parameters, 49B active per token) and DeepSeek-V4.1-Flash (284B total parameters, 13B active per token).

Users can interact with DeepSeek in three ways: completely free through the consumer web portal (chat.deepseek.com) and mobile apps with one-click toggles for deep thinking and live web search; via DeepSeek's hosted, OpenAI-compatible developer API; or by self-hosting DeepSeek's open-weight checkpoints (including V3, R1, Prover-V2, and distilled Qwen/Llama variants) on private infrastructure. The models excel at competitive mathematics, algorithm design, repository-level software engineering, and structured data extraction, with automatic context caching on the API that slashes repeated prompt costs by over 95%.

In late 2026, DeepSeek remains the price-performance benchmark for developers and automation workflows. While the consumer chat interface remains free without a mandatory $20/month subscription tier, the developer API transitioned in late 2026 to two primary endpoints—`deepseek-flash` and `deepseek-v4-pro`—with time-of-day pricing. Off-peak API calls cost just $0.15 per million input tokens ($0.003 on cache hits) and $0.60 per million output tokens on Flash, and $0.66 input / $1.98 output on V4-Pro, making it a fraction of the cost of comparable Western frontier models.

**Pricing & Plans:** Free web and mobile chat app at chat.deepseek.com; pay-as-you-go OpenAI-compatible API with off-peak rates at $0.15/1M input ($0.003 cache hit) and $0.60/1M output for deepseek-flash (V4.1-Flash), and $0.66/1M input ($0.022 cache hit) and $1.98/1M output for deepseek-v4-pro (peak weekday UTC hours bill at 2x).

- **DeepSeek-V4 Hybrid Attention & 1M Context:** Leverages a sparse Mixture-of-Experts architecture (49B active parameters out of 1.6T on V4-Pro) to process up to 1 million tokens with minimal latency and memory overhead.
- **Transparent Chain-of-Thought Reasoning:** Pioneered by DeepSeek-R1 and integrated into V3.2 and V4 thinking modes, exposing step-by-step self-verification for complex math, logic, and code debugging.
- **Automatic Context Caching & Off-Peak API Pricing:** Drops input token costs to $0.003/1M on Flash and $0.022/1M on V4-Pro for cache hits, with 50% lower rates during off-peak UTC hours.
- **Free Consumer Web & Mobile Assistant:** Provides free access at chat.deepseek.com and on iOS/Android with document uploads, reasoning mode, and web search without paywalling core models.
- **Open-Weight Ecosystem & Self-Hosting Freedom:** Offers open weights for DeepSeek-V3, R1, Distill variants, and Prover models on Hugging Face and GitHub so enterprises can deploy within air-gapped environments.

**Strengths:** Completely free consumer web and mobile app with deep reasoning and web search included; Ultra-low API token rates ($0.15/$0.60 on Flash, $0.66/$1.98 on V4-Pro off-peak) with up to 98% savings on cached inputs; Drop-in OpenAI API compatibility makes switching or routing between models effortless; Strong open-weight lineage allows teams to self-host or fine-tune models without vendor lock-in

**Limitations:** Hosted API and web app store data on servers in China, prompting compliance restrictions for some Western enterprises and government agencies; Peak-hour API pricing (01:00–04:00 and 06:00–10:00 UTC on weekdays) doubles per-token costs compared to off-peak rates; Lacks native voice mode, video generation, and productivity suite integrations offered by ChatGPT and Google Gemini

[Profile (Markdown)](https://openaitools.app/tool/deepseek.md)

## Second Opinion

Second Opinion turns fact-checking into a right-click action. Instead of opening a new tab, pasting a claim into a chatbot, and rewording your question, you highlight text on a news article, social post, or research page and select "Get Second Opinion" from the context menu. The extension then returns a structured analysis in place, which keeps you inside the reading flow rather than breaking it.

The analysis is deliberately multi-angle. It checks accuracy of the specific claims, flags possible bias or loaded framing, and offers alternative perspectives so you can see how the same facts might be presented differently. The extension itself is free to install and use, and connects to Grok through your own API key, meaning you pay only for the token usage you actually generate rather than a subscription fee.

Because the output is generated by a language model, the developer is explicit that results should be cross-referenced with other reliable sources for high-stakes decisions. It is best understood as a fast first-pass sanity check that surfaces questions worth asking, not a final authority on what is true.

**Pricing & Plans:** The extension is free to install and use. You supply your own Grok API key, so you pay only for token usage per check. No subscription fees or hidden costs for the extension itself.

- **Right-click fact-checking:** Highlight any passage on a website, social platform, or news article and choose Get Second Opinion to receive an analysis without leaving the page.
- **Accuracy verification:** The model assesses the specific claims in the highlighted text and flags statements that appear unsupported or misleading.
- **Bias and framing detection:** Beyond true or false, it points out loaded wording, one-sided framing, and rhetorical choices that shape interpretation.
- **Alternative perspectives:** Each check surfaces opposing viewpoints and context, so you can compare how the same facts are presented elsewhere.
- **Payload-based pricing via your own key:** The extension is free; you connect your own Grok API key and pay only for the tokens each check consumes.

**Strengths:** Works inline through a right-click, so verification does not break your reading flow; Goes beyond true or false to flag bias, framing, and missing perspectives; Free extension with pay-only-for-usage token costs through your own API key; Available on Brave, Edge, and other Chromium browsers as well as Chrome

**Limitations:** Requires your own Grok API key, which adds a setup step for non-technical users; Costs scale with how much you check, since billing is per token; Output is model-generated and can itself be wrong, so important claims still need primary-source review; Not yet available on Firefox or Safari

[Profile (Markdown)](https://openaitools.app/tool/second-opinion.md)

## Frequently Asked Questions

### How do DeepSeek and Second Opinion compare in monthly traffic?

DeepSeek has 372,761,591 monthly visits, while Second Opinion has 0. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

DeepSeek has a month-over-month growth rate of +4.3%; Second Opinion has 0%.

### How does pricing compare?

DeepSeek: Freemium. Free web and mobile chat app at chat.deepseek.com; pay-as-you-go OpenAI-compatible API with off-peak rates at $0.15/1M input ($0.003 cache hit) and $0.60/1M output for deepseek-flash (V4.1-Flash), and $0.66/1M input ($0.022 cache hit) and $1.98/1M output for deepseek-v4-pro (peak weekday UTC hours bill at 2x). Second Opinion: Freemium. The extension is free to install and use. You supply your own Grok API key, so you pay only for token usage per check. No subscription fees or hidden costs for the extension itself.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [ChatGPT](https://openaitools.app/tool/chatgpt-4) | 6,048,022,723 | +2.2% | Freemium | Provides stronger multi-modal reasoning and agentic tools, but lacks DeepSeek's ultra-low-cost API pricing. | [.md](https://openaitools.app/tool/chatgpt-4.md) |
| 2 | [Google Gemini](https://openaitools.app/tool/gemini-gemini-advanced) | 2,637,398,242 | -0.1% | Freemium | Offers an enormous context window and deep Google ecosystem integration, but feels less specialized for pure reasoning tasks. | [.md](https://openaitools.app/tool/gemini-gemini-advanced.md) |
| 3 | [Claude](https://openaitools.app/tool/claude-2) | 1,253,439,413 | +23.8% | Freemium | Delivers superior long-form coding artifacts and nuanced writing, but lacks DeepSeek's specialized open-weight reasoning models. | [.md](https://openaitools.app/tool/claude-2.md) |
| 4 | [Grok](https://openaitools.app/tool/grok) | 203,846,050 | -0.8% | Freemium | Features real-time X social data integration, but is less cost-effective for dedicated developer coding workflows. | [.md](https://openaitools.app/tool/grok.md) |
| 5 | [Perplexity](https://openaitools.app/tool/perplexity-ai) | 88,310,223 | -3.7% | Freemium | Real-time AI answer engine and research workspace combining live web citations with frontier reasoning models. | [.md](https://openaitools.app/tool/perplexity-ai.md) |
| 6 | [Qwen 4 (Alibaba Qwen4)](https://openaitools.app/tool/qwen-4) | 35,101,353 | -6.2% | Freemium | Provides comparable open-weight foundation models and multilingual performance, but requires self-hosting or third-party inference setup. | [.md](https://openaitools.app/tool/qwen-4.md) |
| 7 | [Cursor](https://openaitools.app/tool/cursor) | 23,297,751 | +8.4% | Freemium | The AI coding agent for building ambitious software | [.md](https://openaitools.app/tool/cursor.md) |
| 8 | [GPTZero](https://openaitools.app/tool/gptzero-me) | 23,246,989 | +32.5% | Freemium, Paid | AI detection and writing verification built for schools and editors | [.md](https://openaitools.app/tool/gptzero-me.md) |
| 9 | [Kimi AI](https://openaitools.app/tool/kimi-chat) | 19,632,261 | -23.4% | Free | Excels at ultra-long document analysis and research, but lacks the same level of open-weight developer community support. | [.md](https://openaitools.app/tool/kimi-chat.md) |
| 10 | [Ollama](https://openaitools.app/tool/ollama) | 9,421,973 | +4.3% | Free, Freemium, Paid | Enables running open-source models locally on consumer hardware, but lacks DeepSeek's cloud-scale hosted reasoning power. | [.md](https://openaitools.app/tool/ollama.md) |

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Source: https://openaitools.app/compare/deepseek-vs-second-opinion

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