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DeepSeek V2.5 vs GPT-5.5

0 vs 1 benchmarks won

DeepSeek
DeepSeek V2.5
OpenAI
GPT-5.5
Overview
CompanyDeepSeekOpenAI
Release dateSep 2024Apr 23 2026
Model type
Open sourceYesNo
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
93.6%
Software engineering
SWE-Bench Verified
Multimodal understanding
MMMU
Timeline
Release gapDeepSeek V2.5 shipped 599 days before GPT-5.5

Which is better: DeepSeek V2.5 or GPT-5.5?

GPT-5.5 leads DeepSeek V2.5 on 1 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). DeepSeek V2.5 shipped 599 days before GPT-5.5, so benchmark comparisons should account for the intervening progress.

DeepSeek V2.5 is an open-source / open-weight model; GPT-5.5 is proprietary.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was DeepSeek V2.5 released?
DeepSeek V2.5 was released by DeepSeek on Sep 2024.
When was GPT-5.5 released?
GPT-5.5 was released by OpenAI on Apr 23 2026.
Is DeepSeek V2.5 or GPT-5.5 open source?
DeepSeek V2.5 is an open-source / open-weight model released by DeepSeek. GPT-5.5 is a proprietary model released by OpenAI.

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