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GPT-4o vs Gemini 1.5 Flash

Pricing, context window, and benchmark comparison · Last updated April 2026

Quick Verdict

Gemini 1.5 Flash is cheaper than GPT-4o at $0.07/1M/1M vs $2.50/1M/1M input tokens — a 33.3x cost difference. GPT-4o scores higher on quality benchmarks (ELO 1286). Choose Gemini 1.5 Flash for cost-sensitive workloads; choose GPT-4o for maximum quality.

Detailed Comparison

MetricGPT-4oGemini 1.5 Flash
Input Price / 1M tokens$2.50/1M$0.07/1MCheaper
Output Price / 1M tokens$10.00/1M$0.30/1MCheaper
Context Window128K1MLarger
ELO Score (LMSYS)1286Smarter1211
Open Source
Free Tier
Release Date2024-052024-05

Which is cheaper: GPT-4o or Gemini 1.5 Flash?

Gemini 1.5 Flash is the cheaper option at $0.07/1M per 1M input tokens, compared to $2.50/1M for GPT-4o. That is a 33.3x cost difference on input tokens. Output pricing follows a similar pattern: GPT-4o charges $10.00/1M/1M vs $0.30/1M/1M for Gemini 1.5 Flash.

Which has better quality: GPT-4o or Gemini 1.5 Flash?

Based on LMSYS Chatbot Arena rankings, GPT-4o achieves a higher ELO score (1286 vs 1211), suggesting stronger performance on open-ended tasks. GPT-4o excels at multimodal: handles text, images, and audio natively. Gemini 1.5 Flash is known for one of the cheapest high-quality models available.

Which should you choose: GPT-4o or Gemini 1.5 Flash?

Choose GPT-4o if:
  • Multimodal: handles text, images, and audio natively
  • Strong reasoning and instruction following
  • Excellent coding capabilities
Choose Gemini 1.5 Flash if:
  • One of the cheapest high-quality models available
  • 1M token context window
  • Very fast inference

Frequently Asked Questions

Which is cheaper: GPT-4o or Gemini 1.5 Flash?

Gemini 1.5 Flash is cheaper at $0.07/1M per 1M input tokens, making it 33.3x more affordable.

Which has better quality: GPT-4o or Gemini 1.5 Flash?

GPT-4o scores higher on the LMSYS Chatbot Arena with an ELO of 1286, suggesting better overall quality for most tasks.

Which has a larger context window: GPT-4o or Gemini 1.5 Flash?

Gemini 1.5 Flash has a larger context window at 1000K tokens.

Should I choose GPT-4o or Gemini 1.5 Flash?

Choose Gemini 1.5 Flash if cost is the priority. Choose GPT-4o if benchmark quality is most important. Consider your specific use case: GPT-4o is best for coding and image-understanding, while Gemini 1.5 Flash excels at low-cost and fast-response.

Is GPT-4o or Gemini 1.5 Flash open source?

GPT-4o is proprietary. Gemini 1.5 Flash is proprietary.

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