DeepSeek-V4-Flash-Max vs GPT-5.1 Instant
DeepSeek-V4-Flash-Max has a slight edge in benchmark performance. DeepSeek-V4-Flash-Max is 19.6x cheaper per token.
DeepSeek · OpenAI · Updated for 2026
Which is better?
DeepSeek-V4-Flash-Max outperforms in 1 benchmarks (SWE-Bench Verified), while GPT-5.1 Instant is better at 0 benchmarks. DeepSeek-V4-Flash-Max has a slight edge in benchmark performance.
On price, DeepSeek-V4-Flash-Max is roughly 19.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
DeepSeek-V4-Flash-Max also accepts a larger context window (1,048,576 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-Max
- cost matters — it's about 19.6x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Apr 2026
- you need open weights you can self-host or fine-tune
Choose GPT-5.1 Instant
- you want predictable pricing at $1.25/M input and $10.00/M output
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
DeepSeek-V4-Flash-Max outperforms in 1 benchmarks (SWE-Bench Verified), while GPT-5.1 Instant is better at 0 benchmarks.
DeepSeek-V4-Flash-Max has a slight edge in benchmark performance.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, DeepSeek-V4-Flash-Max ($0.14/1M tokens) is 8.9x cheaper than GPT-5.1 Instant ($1.25/1M tokens).
For output processing, DeepSeek-V4-Flash-Max ($0.28/1M tokens) is 35.7x cheaper than GPT-5.1 Instant ($10.00/1M tokens).
In conclusion, GPT-5.1 Instant is more expensive than DeepSeek-V4-Flash-Max.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
DeepSeek-V4-Flash-Max accepts 1,048,576 input tokens compared to GPT-5.1 Instant's 400,000 tokens. DeepSeek-V4-Flash-Max can generate longer responses up to 393,216 tokens, while GPT-5.1 Instant is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.1 Instant supports multimodal inputs, whereas DeepSeek-V4-Flash-Max does not.
GPT-5.1 Instant can handle both text and other forms of data like images, making it suitable for multimodal applications.
DeepSeek-V4-Flash-Max
GPT-5.1 Instant
License
Usage and distribution terms
DeepSeek-V4-Flash-Max is licensed under MIT, while GPT-5.1 Instant 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-Max was released on 2026-04-23, while GPT-5.1 Instant was released on 2025-11-12.
DeepSeek-V4-Flash-Max is 5 months newer than GPT-5.1 Instant.
Apr 23, 2026
4 months ago
5mo newerNov 12, 2025
9 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
DeepSeek-V4-Flash-Max is available from DeepSeek. GPT-5.1 Instant is available from OpenAI.
DeepSeek-V4-Flash-Max
GPT-5.1 Instant
Outputs Comparison
Judge for yourself.
Run your own prompts against DeepSeek-V4-Flash-Max and GPT-5.1 Instant side-by-side, then vote on the output you prefer.
FAQ
Common questions about DeepSeek-V4-Flash-Max vs GPT-5.1 Instant.