token.app › Compare › GPT-5.5 vs DeepSeek V4 Pro
GPT-5.5 vs DeepSeek V4 Pro
GPT-5.5 and DeepSeek V4 Pro split the 4 shared benchmarks evenly. DeepSeek V4 Pro is 21× cheaper per token on a blended 3:1 basis. GPT-5.5 accepts the larger context window (1.1M).
Head to head
Blended price uses a 3:1 input:output mix
| GPT-5.5 | DeepSeek V4 Pro | |
|---|---|---|
| Provider | OpenAI | DeepSeek |
| Input $/1M | $5.00 | $0.435 |
| Output $/1M | $30.00 | $0.870 |
| Blended $/1M | $11.25 | $0.544 |
| Context window | 1.1M | 1.0M |
| Max output | 128K | 384K |
| Released | Apr 2026 | Apr 2026 |
| Licence | Proprietary | Open weights |
| GPQA Diamond | 90.7% | 90.9% |
| FrontierMath T1–3 | 85.3% | 45.3% |
| FrontierMath T4 | 72.5% | 2.4% |
| OTIS Mock AIME | 84.4% | 96.7% |
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 if…
- Higher FrontierMath T1–3 (85.3% vs 45.3%)
- Higher FrontierMath T4 (72.5% vs 2.4%)
- Larger context window (1.1M)
- Newer model (released Apr 2026)
Choose DeepSeek V4 Pro if…
- Costs less per token — $0.544 vs $11.25 blended
- Higher GPQA Diamond (90.9% vs 90.7%)
- Higher OTIS Mock AIME (96.7% vs 84.4%)
- Open weights — self-hostable
FAQ
Which is better, GPT-5.5 or DeepSeek V4 Pro?
Across the 4 benchmarks both models have independently-run scores for, GPT-5.5 leads on 2 and DeepSeek V4 Pro leads on 2. Benchmarks are one input — price and context window are on this page too.
Is GPT-5.5 cheaper than DeepSeek V4 Pro?
DeepSeek V4 Pro is cheaper: $0.544 versus $11.25 per million tokens blended at 3:1 input:output. Input alone: $5.00 vs $0.435. Output alone: $30.00 vs $0.870.
What context windows do GPT-5.5 and DeepSeek V4 Pro have?
GPT-5.5: 1,050,000 tokens. DeepSeek V4 Pro: 1,048,576 tokens.
Who makes GPT-5.5 and DeepSeek V4 Pro?
GPT-5.5 is made by OpenAI. DeepSeek V4 Pro is made by DeepSeek.