Gemini 2.5 Pro Preview (May' 25) vs GPT-5.3 Codex (xhigh): Which AI Model Is Better?

Updated March 26, 2026· Based on independent benchmark data

Quick Verdict

GPT-5.3 Codex (xhigh) leads in intelligence with a score of 54.0 vs 29.5. For speed, GPT-5.3 Codex (xhigh) wins at 72 tok/s vs 0 tok/s.

Head-to-Head Comparison

Metric	Gemini 2.5 Pro Preview (May' 25)	GPT-5.3 Codex (xhigh)
Intelligence Score	29.5	54.0
Coding Score	N/A	53.1
Math Score	N/A	N/A
Speed (tok/s)	0 tok/s	72 tok/s
Latency (TTFT)	0.00s	83.91s
Input Price / 1M tokens	$1.25	$1.75
Output Price / 1M tokens	$10	$14
Context Window	N/A

Detailed Analysis

Intelligence & Quality

GPT-5.3 Codex (xhigh) outperforms Gemini 2.5 Pro Preview (May' 25) on the intelligence index with a score of 54.0 compared to 29.5.

Speed & Latency

GPT-5.3 Codex (xhigh) generates output significantly faster at 72 tok/s compared to Gemini 2.5 Pro Preview (May' 25)'s 0 tok/s, making it Infinityx faster for streaming responses. Time to first token is 0.00s for Gemini 2.5 Pro Preview (May' 25) vs 83.91s for GPT-5.3 Codex (xhigh), which affects perceived responsiveness in interactive applications.

Pricing

Gemini 2.5 Pro Preview (May' 25) is more affordable at $1.25/1M input tokens ($10/1M output), while GPT-5.3 Codex (xhigh) costs $1.75/1M input ($14/1M output). For a typical workload of 100 requests per day at 2,000 tokens each, Gemini 2.5 Pro Preview (May' 25) would cost approximately $7.50/month vs $10.50/month for GPT-5.3 Codex (xhigh) in input costs alone.

Best Use Cases

Choose GPT-5.3 Codex (xhigh) when you need higher intelligence (54.0), faster output (72 tok/s).

Choose Gemini 2.5 Pro Preview (May' 25) if:

✓You want lower latency (0.00s vs 83.91s TTFT)

Choose GPT-5.3 Codex (xhigh) if:

✓You need higher intelligence (score: 54.0 vs 29.5)
✓You need faster throughput (72 tok/s vs 0 tok/s)

Frequently Asked Questions

Which is cheaper, Gemini 2.5 Pro Preview (May' 25) or GPT-5.3 Codex (xhigh)?

Gemini 2.5 Pro Preview (May' 25) is cheaper at $1.25/1M input tokens vs $1.75/1M for GPT-5.3 Codex (xhigh).

Is Gemini 2.5 Pro Preview (May' 25) faster than GPT-5.3 Codex (xhigh)?

GPT-5.3 Codex (xhigh) is faster, producing output at 72 tok/s compared to Gemini 2.5 Pro Preview (May' 25)'s 0 tok/s.

Can Gemini 2.5 Pro Preview (May' 25) process images?

No, Gemini 2.5 Pro Preview (May' 25) does not support image input. Neither model supports image input.

Should I use Gemini 2.5 Pro Preview (May' 25) or GPT-5.3 Codex (xhigh)?

It depends on your priorities. GPT-5.3 Codex (xhigh) scores higher on intelligence (54.0), but Gemini 2.5 Pro Preview (May' 25) may be better for specific use cases like budget-conscious projects or speed-critical applications.

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View Gemini 2.5 Pro Preview (May' 25)details →View GPT-5.3 Codex (xhigh)details →Full pricing comparison →

Data last synced: March 26, 2026