GPT-5.4 Pro vs Horizon Alpha
Compare GPT-5.4 Pro by OpenAI against Horizon Alpha by OpenRouter, context windows of 1.1M vs 256K, tested across 2 shared challenges. Updated April 2026.
Which is better, GPT-5.4 Pro or Horizon Alpha?
GPT-5.4 Pro and Horizon Alpha are both competitive models. GPT-5.4 Pro costs $30/M input tokens vs $0/M for Horizon Alpha. Context windows: 1050K vs 256K tokens. Compare their real outputs side by side below.
Key Differences Between GPT-5.4 Pro and Horizon Alpha
GPT-5.4 Pro is made by openai while Horizon Alpha is from openrouter. GPT-5.4 Pro has a 1050K token context window compared to Horizon Alpha's 256K. On pricing, GPT-5.4 Pro costs $30/M input tokens vs $0/M for Horizon Alpha.
No community votes yet. On paper, GPT-5.4 Pro has the edge — bigger model tier, newer, bigger context window, major provider backing.
Style Comparison
GPT-5.4 Pro uses 745.3x more bold
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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
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12
clone pairs
32
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279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
