Gemini 2.5 Pro, released in March 2025, has training data up to January 2025, while ChatGPT 4.5, released earlier, has training data up to October 2023.
Gemini 2.5 Pro supports a context window of up to 1 million tokens (with plans to expand to 2 million), whereas ChatGPT 4.5 offers a 128,000-token context window.
Gemini 2.5 Pro natively processes text, images, audio, and video, while ChatGPT 4.5 primarily focuses on text-based interactions. citeturn0search3
In reasoning-based evaluations, Gemini 2.5 Pro scored 18.8% on Humanity's Last Exam, outperforming ChatGPT 4.5's 6.4%, indicating superior logical and analytical abilities.
Gemini 2.5 Pro leads in code editing with a 74.0% score on Aider Polyglot, surpassing ChatGPT 4.5's 44.9%, and in agentic coding with a 63.8% score on SWE-bench verified, compared to ChatGPT 4.5's 38.0%.