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DeepSeek V4 vs Gemini 3.5

2026 - Pricing, benchmarks, and use case comparison

Quick take

  • DeepSeek V4 is open-weights - free to self-host with no API costs. Gemini 3.5 requires paid API access.
  • Gemini 3.5 has a 1M context window - 8x larger than DeepSeek V4's 128K. Better for long documents and large codebases.
  • DeepSeek V4 is open-source: fine-tune it, self-host it, or use any inference provider. Gemini 3.5 is closed-source.

Specs comparison

DeepSeek V4Gemini 3.5
ProviderDeepSeekGoogle DeepMind
TypeOpen sourceClosed source
Context window128K1M
Input / 1M tokensFree (self-host)TBA
Output / 1M tokensFree (self-host)TBA
Release date2025-122026-05

Strengths

DeepSeek V4

  • Mixture-of-Experts architecture - high capability, low activation cost
  • Open-source weights freely available
  • Strong coding and reasoning benchmarks
  • Flash variant offers low-latency inference
  • Significantly cheaper to run than US frontier models

Gemini 3.5

  • Action-first architecture for agentic and multi-step workflows
  • 1M token context window - largest in class
  • Powers Google Antigravity CLI for terminal-native coding
  • Native Workspace integration with autonomous task execution
  • Companion Gemini Omni handles anything-to-anything multimodal generation

Which should you choose?

Choose DeepSeek V4 if you need...

  • Self-hosted deployments needing frontier performance
  • Cost-sensitive high-volume inference
  • Coding and technical tasks
  • Researchers studying MoE architectures
Full DeepSeek V4 details →

Choose Gemini 3.5 if you need...

  • Agentic workflows requiring multi-step tool use
  • Large codebase comprehension and editing
  • Google Workspace automation
  • Long document and multimodal analysis
Full Gemini 3.5 details →

Compare DeepSeek V4 with others