DeepSeek-V4-Flash-0731 vs GPT-5.5
Both models are evenly matched across the benchmarks. DeepSeek-V4-Flash-0731 is 100.0x cheaper per token.
DeepSeek · OpenAI · Updated for 2026
Which is better?
DeepSeek-V4-Flash-0731 outperforms in 1 benchmarks (Toolathlon), while GPT-5.5 is better at 1 benchmark (CyberGym). Both models are evenly matched across the benchmarks.
On price, DeepSeek-V4-Flash-0731 is roughly 100.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.5 also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose DeepSeek-V4-Flash-0731
- cost matters — it's about 100.0x cheaper per token
- you want the most recent training data — it shipped Jul 2026
- you need open weights you can self-host or fine-tune
Choose GPT-5.5
- you process long inputs — it offers a 1,050,000 token context window
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
DeepSeek-V4-Flash-0731 outperforms in 1 benchmarks (Toolathlon), while GPT-5.5 is better at 1 benchmark (CyberGym).
Both models are evenly matched across the benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, DeepSeek-V4-Flash-0731 ($0.09/1M tokens) is 55.6x cheaper than GPT-5.5 ($5.00/1M tokens).
For output processing, DeepSeek-V4-Flash-0731 ($0.18/1M tokens) is 166.7x cheaper than GPT-5.5 ($30.00/1M tokens).
In conclusion, GPT-5.5 is more expensive than DeepSeek-V4-Flash-0731.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 accepts 1,050,000 input tokens compared to DeepSeek-V4-Flash-0731's 1,048,576 tokens. GPT-5.5 can generate longer responses up to 128,000 tokens, while DeepSeek-V4-Flash-0731 is limited to 65,536 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.5 supports multimodal inputs, whereas DeepSeek-V4-Flash-0731 does not.
GPT-5.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.
DeepSeek-V4-Flash-0731
GPT-5.5
License
Usage and distribution terms
DeepSeek-V4-Flash-0731 is licensed under MIT, while GPT-5.5 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
MIT
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
DeepSeek-V4-Flash-0731 was released on 2026-07-31, while GPT-5.5 was released on 2026-04-23.
DeepSeek-V4-Flash-0731 is 3 months newer than GPT-5.5.
Jul 31, 2026
3 weeks ago
3mo newerApr 23, 2026
4 months ago
Knowledge Cutoff
When training data ends
GPT-5.5 has a documented knowledge cutoff of 2025-12-01, while DeepSeek-V4-Flash-0731's cutoff date is not specified.
We can confirm GPT-5.5's training data extends to 2025-12-01, but cannot make a direct comparison without DeepSeek-V4-Flash-0731's cutoff date.
—
Dec 2025
Provider Availability
DeepSeek-V4-Flash-0731 is available from DeepInfra, Novita, Fireworks. GPT-5.5 is available from OpenAI.
DeepSeek-V4-Flash-0731
GPT-5.5
Outputs Comparison
Judge for yourself.
Run your own prompts against DeepSeek-V4-Flash-0731 and GPT-5.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about DeepSeek-V4-Flash-0731 vs GPT-5.5.