Gemini 2.5 Flash vs GPT-4o

API pricing, context window and capabilities for Gemini 2.5 Flash and GPT-4o, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.

Verdict

computed from the published numbers

Gemini 2.5 Flash wins on price, on intelligence and on context window. Benchmark data is unavailable for one or both models.

Price
Gemini 2.5 Flash
Coding
Not called
Intelligence
Gemini 2.5 Flash
Context window
Gemini 2.5 Flash

Key takeaways

who wins on what, from the published numbers

Gemini 2.5 Flash wins

  • Cheaper input ($0.15 vs $2.50 /1M)
  • Cheaper output ($0.60 vs $10.00 /1M)
  • Larger context window (1M vs 131K)
  • Higher max output (1M vs 16K)
  • More serving providers (8 vs 6)
  • Has reasoning mode
  • Has web search

GPT-4o wins

No clear edge on the tracked metrics.

Cheaper overall
Gemini 2.5 Flash
$0.15 + $0.60 /1M
Larger context
Gemini 2.5 Flash
1M
More providers
Gemini 2.5 Flash
8 providers

Pricing & specs

cheapest serving route · per 1M tokens
Gemini 2.5 FlashGPT-4o
Input $/1M$0.15 best$2.50
Output $/1M$0.60 best$10.00
Context window1M best131K
Max output1M best16K
Serving providers8 best6
Released2025-06-17 2024-05-13

Benchmarks

Artificial Analysis indices, side by side
Gemini 2.5 FlashGPT-4o
Intelligence14.1 best11.2
GPQA Diamond68% best54%
Output speed233 t/s best99 t/s
Latency (TTFT)4.98s best5.19s

Cost calculator

choose a serving route for each side
Input tokens / month
Output tokens / month
Gemini 2.5 Flash
via OCI
$1.35
GPT-4o
via Azure
$23

Capabilities

feature support, side by side
FeatureGemini 2.5 FlashGPT-4o
Vision
Tool use
Reasoning
Audio
Prompt caching
Structured output
Web search

Related comparisons

Frequently asked questions

Which is cheaper, Gemini 2.5 Flash or GPT-4o?
Gemini 2.5 Flash is cheaper for input ($0.15 vs $2.50 per 1M tokens). Gemini 2.5 Flash is cheaper for output ($0.60 vs $10.00 per 1M tokens).
What is the context window difference between Gemini 2.5 Flash and GPT-4o?
Gemini 2.5 Flash has a 1M-token context window and GPT-4o has 131K tokens, so Gemini 2.5 Flash can take a larger prompt.
How do Gemini 2.5 Flash and GPT-4o compare on benchmarks?
On the tracked Artificial Analysis indices, Gemini 2.5 Flash leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily

Every weekday

AI moves fast. Here's your debrief.

News, analysis, tools, and more.

For people who build with AI