GPT-3.5 Turbo vs GPT-5 Pro

Compare GPT-3.5 Turbo and GPT-5 Pro, both from OpenAI, context windows of 16K vs 400K, tested across 17 shared challenges. Updated April 2026.

Which is better, GPT-3.5 Turbo or GPT-5 Pro?

GPT-3.5 Turbo and GPT-5 Pro are both competitive models. GPT-3.5 Turbo costs $1.5/M input tokens vs $15/M for GPT-5 Pro. Context windows: 16K vs 400K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-3.5 Turbo and GPT-5 Pro

GPT-3.5 Turbo is made by openai while GPT-5 Pro is from openai. GPT-3.5 Turbo has a 16K token context window compared to GPT-5 Pro's 400K. On pricing, GPT-3.5 Turbo costs $1.5/M input tokens vs $15/M for GPT-5 Pro.

Our Verdict
GPT-5 Pro
GPT-5 Pro
GPT-3.5 Turbo
GPT-3.5 TurboRunner-up

No community votes yet. On paper, GPT-5 Pro has the edge — bigger model tier, newer, bigger context window.

GPT-3.5 Turbo is 60x cheaper per token — worth considering if cost matters.

Slight edge
Writing DNA

Style Comparison

Similarity
90%

GPT-3.5 Turbo uses 38.3x more transitions

GPT-3.5 Turbo
GPT-5 Pro
61%Vocabulary65%
16wSentence Length15w
0.23Hedging0.32
0.0Bold0.0
3.7Lists2.9
0.00Emoji0.00
0.00Headings0.00
0.38Transitions0.01
Based on 11 + 11 text responses
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GPT-3.5 TurboGPT-5 Pro

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
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