Model Comparison

DeepSeek-V2.5 vs GPT-5.1 Thinking

GPT-5.1 Thinking significantly outperforms across most benchmarks. DeepSeek-V2.5 is 19.6x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

DeepSeek-V2.5 outperforms in 0 benchmarks, while GPT-5.1 Thinking is better at 1 benchmark (SWE-Bench Verified).

GPT-5.1 Thinking significantly outperforms across most benchmarks.

Sat Apr 18 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

DeepSeek-V2.5 costs less

For input processing, DeepSeek-V2.5 ($0.14/1M tokens) is 8.9x cheaper than GPT-5.1 Thinking ($1.25/1M tokens).

For output processing, DeepSeek-V2.5 ($0.28/1M tokens) is 35.7x cheaper than GPT-5.1 Thinking ($10.00/1M tokens).

In conclusion, GPT-5.1 Thinking is more expensive than DeepSeek-V2.5.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sat Apr 18 2026 • llm-stats.com
DeepSeek
DeepSeek-V2.5
Input tokens$0.14
Output tokens$0.28
Best providerDeepSeek
OpenAI
GPT-5.1 Thinking
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.1 Thinking accepts 400,000 input tokens compared to DeepSeek-V2.5's 8,192 tokens. GPT-5.1 Thinking can generate longer responses up to 128,000 tokens, while DeepSeek-V2.5 is limited to 8,192 tokens.

DeepSeek
DeepSeek-V2.5
Input8,192 tokens
Output8,192 tokens
OpenAI
GPT-5.1 Thinking
Input400,000 tokens
Output128,000 tokens
Sat Apr 18 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.1 Thinking supports multimodal inputs, whereas DeepSeek-V2.5 does not.

GPT-5.1 Thinking can handle both text and other forms of data like images, making it suitable for multimodal applications.

DeepSeek-V2.5

Text
Images
Audio
Video

GPT-5.1 Thinking

Text
Images
Audio
Video

License

Usage and distribution terms

DeepSeek-V2.5 is licensed under deepseek, while GPT-5.1 Thinking uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

DeepSeek-V2.5

deepseek

Open weights

GPT-5.1 Thinking

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V2.5 was released on 2024-05-08, while GPT-5.1 Thinking was released on 2025-11-12.

GPT-5.1 Thinking is 18 months newer than DeepSeek-V2.5.

DeepSeek-V2.5

May 8, 2024

1.9 years ago

GPT-5.1 Thinking

Nov 12, 2025

5 months ago

1.5yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

DeepSeek-V2.5 is available from DeepSeek, DeepInfra, Hyperbolic. GPT-5.1 Thinking is available from OpenAI.

DeepSeek-V2.5

deepseek logo
DeepSeek
Input Price:Input: $0.14/1MOutput Price:Output: $0.28/1M
deepinfra logo
Deepinfra
Input Price:Input: $0.70/1MOutput Price:Output: $1.40/1M
hyperbolic logo
Hyperbolic
Input Price:Input: $2.00/1MOutput Price:Output: $2.00/1M

GPT-5.1 Thinking

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

DeepSeek
Less expensive input tokens
Less expensive output tokens
Has open weights
OpenAI
Larger context window (400,000 tokens)
Supports multimodal inputs
Higher SWE-Bench Verified score (76.3% vs 16.8%)

Detailed Comparison

AI Model Comparison Table
Feature
DeepSeek
DeepSeek-V2.5
OpenAI
GPT-5.1 Thinking

FAQ

Common questions about DeepSeek-V2.5 vs GPT-5.1 Thinking

GPT-5.1 Thinking significantly outperforms across most benchmarks. DeepSeek-V2.5 is made by DeepSeek and GPT-5.1 Thinking is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
DeepSeek-V2.5 scores GSM8k: 95.1%, MT-Bench: 90.2%, HumanEval: 89.0%, BBH: 84.3%, AlignBench: 80.4%. GPT-5.1 Thinking scores Tau2 Telecom: 95.6%, AIME 2025: 94.0%, BrowseComp Long Context 128k: 90.0%, GPQA: 88.1%, MMMU: 85.4%.
DeepSeek-V2.5 is 8.9x cheaper for input tokens. DeepSeek-V2.5 costs $0.14/M input and $0.28/M output via deepseek. GPT-5.1 Thinking costs $1.25/M input and $10.00/M output via openai.
DeepSeek-V2.5 supports 8K tokens and GPT-5.1 Thinking supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (8K vs 400K), input pricing ($0.14 vs $1.25/M), multimodal support (no vs yes), licensing (deepseek vs Proprietary). See the full comparison above for benchmark-by-benchmark results.
DeepSeek-V2.5 is developed by DeepSeek and GPT-5.1 Thinking is developed by OpenAI.