Compare/Gemini 3.5 Flash (high) vs o3

Gemini 3.5 Flash (high)vso3

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

Google

Gemini 3.5 Flash (high)

Input
$1.5/M
Output
$9/M
Speed
227 tok/s
TTFT
9.75s
OpenAI

o3

Input
$2/M
Output
$8/M
Speed
86 tok/s
TTFT
8.97s

Winner by Category

Cheaper
Gemini 3.5 Flash (high)
Faster (tok/s)
Gemini 3.5 Flash (high)
Lower Latency
o3
Benchmarks (7-5)
Gemini 3.5 Flash (high)

Pricing Comparison

MetricGemini 3.5 Flash (high)o3
Input ($/M tokens)$1.5$2
Output ($/M tokens)$9$8
Cost for 1M input + 100K output tokens:
Gemini 3.5 Flash (high)$2.40
o3$2.80

Speed Comparison

Output Speed (tokens/s) — higher is better
Gemini 3.5 Flash (high)
227 tok/s
o3
86 tok/s
Time to First Token (seconds) — lower is better
Gemini 3.5 Flash (high)
9.75s
o3
8.97s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
55.338.4
Coding Index
45.038.4
Math Index
88.3
GPQA Diamond
92.2%82.7%
MMLU-Pro
85.3%
LiveCodeBench
80.8%
AIME 2025
88.3%
MATH-500
99.2%
Humanity's Last Exam
41.0%20.0%
SciCode
53.1%41.0%
IFBench
76.3%71.4%
TerminalBench
40.9%37.1%
Gemini 3.5 Flash (high)7 wins
5 winso3

Frequently Asked Questions

Which is cheaper, Gemini 3.5 Flash (high) or o3?

Gemini 3.5 Flash (high) is cheaper overall. Its blended price (3:1 input/output ratio) is $3.38/M tokens vs $3.50/M for o3.

Which model performs better on benchmarks?

Gemini 3.5 Flash (high) wins 7 out of 12 benchmarks compared to 5 for o3. See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

Gemini 3.5 Flash (high) generates tokens faster at 227 tok/s vs 86 tok/s. However, o3 has lower time-to-first-token (8.97s vs 9.75s).

When should I use Gemini 3.5 Flash (high) vs o3?

Choose based on your priorities: Gemini 3.5 Flash (high) for lower cost, Gemini 3.5 Flash (high) for stronger benchmark performance, and Gemini 3.5 Flash (high) for faster generation. For latency-sensitive apps, check the TTFT comparison above.