token.app › Compare › GPT-5.5 Pro vs DeepSeek V4 Flash 0731
GPT-5.5 Pro vs DeepSeek V4 Flash 0731
GPT-5.5 Pro leads on 2 of 2 shared benchmarks. DeepSeek V4 Flash 0731 is 600× cheaper per token on a blended 3:1 basis. GPT-5.5 Pro accepts the larger context window (1.1M).
Head to head
Blended price uses a 3:1 input:output mix
| GPT-5.5 Pro | DeepSeek V4 Flash 0731 | |
|---|---|---|
| Provider | OpenAI | DeepSeek |
| Input $/1M | $30.00 | $0.090 |
| Output $/1M | $180.00 | $0.180 |
| Blended $/1M | $67.50 | $0.113 |
| Context window | 1.1M | 1.0M |
| Max output | 128K | 384K |
| Released | Apr 2026 | Jul 2026 |
| Licence | Proprietary | Open weights |
| FrontierMath T1–3 | 87.7% | 57.5% |
| FrontierMath T4 | 78.0% | 24.4% |
Benchmark scores independently run and published by Epoch AI, 'AI Benchmarking Hub', used under CC BY 4.0. Only benchmarks with a score for BOTH models are compared.
Choose GPT-5.5 Pro if…
- Higher FrontierMath T1–3 (87.7% vs 57.5%)
- Higher FrontierMath T4 (78.0% vs 24.4%)
- Larger context window (1.1M)
Choose DeepSeek V4 Flash 0731 if…
- Costs less per token — $0.113 vs $67.50 blended
- Open weights — self-hostable
- Newer model (released Jul 2026)
FAQ
Which is better, GPT-5.5 Pro or DeepSeek V4 Flash 0731?
Across the 2 benchmarks both models have independently-run scores for, GPT-5.5 Pro leads on 2 and DeepSeek V4 Flash 0731 leads on 0. Benchmarks are one input — price and context window are on this page too.
Is GPT-5.5 Pro cheaper than DeepSeek V4 Flash 0731?
DeepSeek V4 Flash 0731 is cheaper: $0.113 versus $67.50 per million tokens blended at 3:1 input:output. Input alone: $30.00 vs $0.090. Output alone: $180.00 vs $0.180.
What context windows do GPT-5.5 Pro and DeepSeek V4 Flash 0731 have?
GPT-5.5 Pro: 1,050,000 tokens. DeepSeek V4 Flash 0731: 1,048,576 tokens.
Who makes GPT-5.5 Pro and DeepSeek V4 Flash 0731?
GPT-5.5 Pro is made by OpenAI. DeepSeek V4 Flash 0731 is made by DeepSeek.