I've been testing both DeepSeek V4 Pro and GPT-5.4 Pro for the past week, and the results surprised me.
The Price Difference is Insane
Let's start with the elephant in the room. DeepSeek V4 Pro costs ¥24 per million tokens. GPT-5.4 Pro? $200 per month for the subscription, plus API costs that make my wallet cry.
For my daily coding tasks, I honestly couldn't tell the difference in quality. Both handled complex refactoring, both caught edge cases, both gave me working code.
Where GPT-5.4 Wins
The computer control feature is genuinely useful. I showed it a screenshot of my IDE, and it told me exactly which buttons to click. That's something DeepSeek can't do yet.
Also, GPT-5.4's multimodal capabilities feel more polished. Upload an image, ask questions, get detailed answers. Simple and reliable.
Where DeepSeek V4 Surprised Me
The 1M context window isn't just marketing fluff. I fed it an entire codebase - seriously, like 50 files - and it actually remembered details from the first file when we discussed the last one.
The coding quality? I ran a blind test with my team. We couldn't reliably tell which model wrote which code. That's insane considering the price difference.
The Honest Truth
If you're building a product and need reliable API access, DeepSeek V4 is a no-brainer. The cost savings alone could fund your entire infrastructure.
But if you need that computer control feature or the absolute best multimodal experience, GPT-5.4 still holds the crown.
My Recommendation
Start with DeepSeek V4 Flash (¥2/million tokens!) for most tasks. Upgrade to Pro only when you hit its limits. Use GPT-5.4 for specific tasks that need its unique features.
Your wallet will thank you.