Compare ChatGPT-4o (March 2025) by OpenAI against Grok 3 Thinking by xAI, context windows of 128K vs 128K, tested across 11 shared challenges. Updated April 2026.
ChatGPT-4o (March 2025) and Grok 3 Thinking are both competitive models. Context windows: 128K vs 128K tokens. Compare their real outputs side by side below.
ChatGPT-4o (March 2025) is made by openai while Grok 3 Thinking is from xai. ChatGPT-4o (March 2025) has a 128K token context window compared to Grok 3 Thinking's 128K.
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
ChatGPT-4o (March 2025) uses 94.5x more emoji
Ask 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.

Compare ChatGPT-4o (March 2025) by OpenAI against Grok 3 Thinking by xAI, context windows of 128K vs 128K, tested across 11 shared challenges. Updated April 2026.
ChatGPT-4o (March 2025) and Grok 3 Thinking are both competitive models. Context windows: 128K vs 128K tokens. Compare their real outputs side by side below.
ChatGPT-4o (March 2025) is made by openai while Grok 3 Thinking is from xai. ChatGPT-4o (March 2025) has a 128K token context window compared to Grok 3 Thinking's 128K.
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
ChatGPT-4o (March 2025) uses 94.5x more emoji
Ask 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.

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11 fights queued