Gemini 3.5 Flash vs GPT-5.4

API pricing, context window and capabilities for Gemini 3.5 Flash and GPT-5.4, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.

Verdict

computed from the published numbers

Gemini 3.5 Flash wins on price. GPT-5.4 wins on coding, on intelligence and on context window.

Price
Gemini 3.5 Flash
Coding
GPT-5.4
Intelligence
GPT-5.4
Context window
GPT-5.4

Key takeaways

who wins on what, from the published numbers

Gemini 3.5 Flash wins

  • Cheaper input ($1.50 vs $2.50 /1M)
  • Cheaper output ($9.00 vs $15.00 /1M)
  • More serving providers (3 vs 2)
  • Supports audio

GPT-5.4 wins

  • Larger context window (1M vs 1.1M)
  • Higher max output (66K vs 128K)
Cheaper overall
Gemini 3.5 Flash
$1.50 + $9.00 /1M
Larger context
GPT-5.4
1.1M
More providers
Gemini 3.5 Flash
3 providers

Pricing & specs

cheapest serving route · per 1M tokens
Gemini 3.5 FlashGPT-5.4
Input $/1M$1.50 best$2.50
Output $/1M$9.00 best$15.00
Context window1M 1.1M best
Max output66K 128K best
Serving providers3 best2
Released2026-05-22 2026-03-05

Benchmarks

Artificial Analysis indices, side by side
Gemini 3.5 FlashGPT-5.4
Intelligence50.2 51.4 best
Coding70.1 71.0 best
GPQA Diamond92% 92%
Output speed188 t/s best144 t/s
Latency (TTFT)18.79s best27.88s

Cost calculator

choose a serving route for each side
Input tokens / month
Output tokens / month
Gemini 3.5 Flash
via Vertex AI
$17
GPT-5.4
via Azure
$28

Capabilities

feature support, side by side
FeatureGemini 3.5 FlashGPT-5.4
Vision
Tool use
Reasoning
Audio
Prompt caching
Structured output
Web search

Related comparisons

Frequently asked questions

Which is cheaper, Gemini 3.5 Flash or GPT-5.4?
Gemini 3.5 Flash is cheaper for input ($1.50 vs $2.50 per 1M tokens). Gemini 3.5 Flash is cheaper for output ($9.00 vs $15.00 per 1M tokens).
What is the context window difference between Gemini 3.5 Flash and GPT-5.4?
Gemini 3.5 Flash has a 1M-token context window and GPT-5.4 has 1.1M tokens, so GPT-5.4 can take a larger prompt.
How do Gemini 3.5 Flash and GPT-5.4 compare on benchmarks?
On the tracked Artificial Analysis indices, GPT-5.4 leads on coding, and GPT-5.4 leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily

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