Model comparison Synced Mar 10, 2026

Google: Gemini 3.1 Pro Preview Custom Tools vs OpenAI: GPT-5.3-Codex

Side-by-side comparison of Google: Gemini 3.1 Pro Preview Custom Tools and OpenAI: GPT-5.3-Codex. Compare pricing, context window, capabilities, and find out which is better for your workflow.

Verdict

strong confidence

Google: Gemini 3.1 Pro Preview Custom Tools leads overall

Google: Gemini 3.1 Pro Preview Custom Tools leads in price and context window and capabilities, making it the stronger choice for most workflows. OpenAI: GPT-5.3-Codex remains competitive with advantages in max output.

Best for with Google: Gemini 3.1 Pro Preview Custom Tools

Budget-conscious workflowsLong document processingMulti-modal tasks

Best for with OpenAI: GPT-5.3-Codex

Long-form content generation

Side-by-side

Technical specifications

	Google: Gemini 3.1 Pro Preview Custom Tools	OpenAI: GPT-5.3-Codex
Provider	Google	OpenAI
Input price	$2/M	$2/M
Output price	$12/M	$14/M
Context window	1.0M	400K
Max output	66K	128K
Capabilities	Tool useVisionAudioReasoning	Tool useVisionReasoning
Released	Feb 25, 2026	Feb 24, 2026

View Google: Gemini 3.1 Pro Preview Custom Tools profile View OpenAI: GPT-5.3-Codex profile

Scoring breakdown