Before Choosing a Model, Ask Yourself This
The question "which model is best" is fundamentally flawed. GPT-5.5, Claude Opus 4.7, and DeepSeek V4 Pro each excel in different areas — no single model dominates across all dimensions. The right choice depends on what you're using it for.
Here's a breakdown across six dimensions.
Pricing
This is where the biggest gap exists.
| Model | Input (¥/M) | Output (¥/M) |
|---|---|---|
| DeepSeek V4 Pro | ¥2.96 | ¥5.92 |
| ChatGPT (GPT-5.5) | ¥34.00 | ¥204.00 |
| Claude Opus 4.7 | ¥34.00 | ¥170.00 |
DeepSeek costs 1/10 to 1/35 of ChatGPT and Claude. For applications requiring heavy API usage (agent loops, batch processing, data labeling), this gap directly impacts operating costs.
Example: processing 1M tokens of output daily, GPT-5.5 costs ¥612,000/month versus DeepSeek V4 Pro at ¥17,760/month — a 34x difference.
However, both ChatGPT and Claude have cheaper lightweight versions: GPT-5.5 Instant (¥5.10/¥20.40) and Claude Haiku 4.5 (¥5.44/¥27.20). If you don't need top-tier reasoning, these save significant money.
Coding Ability
All three models are strong coders, but with different styles.
Claude Opus 4.7 produces the "cleanest" code. Well-structured, fully commented, consistent naming — like a senior engineer with strong opinions about code quality. It consistently ranks first on benchmarks like SWE-bench. Downsides: slower generation, tends to truncate long code.
GPT-5.5 is the most well-rounded. Beyond coding, it handles requirements analysis, architecture design, and documentation simultaneously. In agent scenarios, GPT-5.5's tool-calling ability is the most stable. The Instant version is fast enough for real-time code completion.
DeepSeek V4 Pro has nearly caught up to Claude in coding ability, and in some benchmarks surpasses GPT-5.5. Its biggest advantage is being open-source — you can deploy locally, keeping code within your network. DeepSeek's code reasoning mode is particularly strong, handling complex algorithms that even Claude struggles with.
Long Context Processing
All three support million-token context windows, but real-world performance differs.
GPT-5.5 (1050K) and Claude Opus 4.7 (1000K) maintain more stable "attention" over long contexts, with higher accuracy when retrieving information from 100K+ token documents. DeepSeek V4 Pro (1049K) shows slightly lower recall on fine details beyond 200K.
For "summarize this 500-page PDF," all three work. For "find a specific clause in a 1000-page contract," Claude and GPT are more reliable.
Chinese Language Ability
DeepSeek and GPT both handle Chinese well. DeepSeek is built by a Chinese team, so its Chinese understanding is the most natural — especially for classical Chinese, idioms, and internet slang. GPT-5.5's Chinese is good but occasionally has a "translation" feel.
Claude's Chinese has improved significantly but still trails the other two in scenarios requiring deep Chinese cultural context.
Reliability
This is often overlooked but practically important.
ChatGPT is the most stable with almost no downtime and generous API rate limits. Claude occasionally has queuing issues during peak hours. DeepSeek's API stability has improved greatly over the past six months but still has a gap compared to OpenAI.
Additionally, ChatGPT and Claude can't be accessed directly from mainland China without a VPN. DeepSeek works directly — a significant advantage for domestic users.
Hidden Costs Beyond API Pricing
Model selection isn't just about per-token pricing. Consider:
- Retry costs: If a model's output needs regeneration, token consumption doubles. Claude and GPT typically have higher first-attempt success rates.
- Prompt engineering costs: Different models have different prompt sensitivity. DeepSeek produces good results with simple prompts; Claude sometimes needs more detailed instructions.
- Integration costs: ChatGPT has the most mature ecosystem with ready-made integrations for nearly every development tool. DeepSeek is compatible with OpenAI's API format, making migration easy.
My Recommendations
Budget-sensitive, high-frequency usage → DeepSeek V4 Pro. The price advantage is massive, and quality is sufficient.
Maximum quality, money is no object → Claude Opus 4.7. For coding, document analysis, and complex reasoning, it's the most reliable.
All-around, stability first → GPT-5.5. Does everything well, most mature ecosystem, least likely to cause problems.
China-based users, no hassle → DeepSeek. Direct access, best Chinese support, lowest price.
Hybrid approach → Many teams use a "routing" strategy: simple tasks go to DeepSeek Flash (¥0.95/¥1.90), complex tasks to Claude Opus, and intermediate tasks to GPT-5.5 Instant. Dynamic model selection based on task difficulty can reduce costs to 1/5 of using GPT alone.
