Gemini 2.5 Flash Preview 05-20 (thinking) vs o1
Compare Gemini 2.5 Flash Preview 05-20 (thinking) by Google AI against o1 by OpenAI, context windows of 1.0M vs 128K, tested across 12 shared challenges. Updated April 2026.
Which is better, Gemini 2.5 Flash Preview 05-20 (thinking) or o1?
Gemini 2.5 Flash Preview 05-20 (thinking) and o1 are both competitive models. Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $15/M for o1. Context windows: 1049K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between Gemini 2.5 Flash Preview 05-20 (thinking) and o1
Gemini 2.5 Flash Preview 05-20 (thinking) is made by google while o1 is from openai. Gemini 2.5 Flash Preview 05-20 (thinking) has a 1049K token context window compared to o1's 128K. On pricing, Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $15/M for o1.
No community votes yet. On paper, Gemini 2.5 Flash Preview 05-20 (thinking) has the edge — newer, bigger context window.
Gemini 2.5 Flash Preview 05-20 (thinking) is 17x cheaper per token — worth considering if cost matters.
Style Comparison
o1 uses 75.8x more hedging
vsAsk them anything yourself
Some models write identically. You are paying for the brand.
178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
178
models
12
clone pairs
32
dimensions
279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
