GPT-5.5 vs o3
Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.
GPT-5.5 by OpenAI wins on 4 of 7 benchmarks against o3 by OpenAI, which leads on 2. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from our benchmark data.
Category-by-Category Breakdown
Coding: In coding, GPT-5.5 scores 1272 on Design Arena ELO compared to o3's 1074, while GPT-5.5 scores 1269 on Website Arena ELO compared to o3's 1048.
Reasoning: In reasoning, GPT-5.5 scores 93.8% on GPQA Diamond compared to o3's 83.3%.
Context: In context, GPT-5.5 scores 1.1M on Context Length compared to o3's 200K.
Pricing Comparison
GPT-5.5 costs $5.0/1M input tokens and $30.0/1M output tokens, while o3 costs $2.0/1M input and $8.0/1M output. o3 is the more affordable option for API usage.
Verdict
o3 leads across the board in affordability, making it the stronger overall choice in this comparison.
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GPT-5.5 vs o3 — FAQ
Which is better, GPT-5.5 or o3?
GPT-5.5 wins on more benchmarks overall (4 vs 2). However, the best choice depends on your specific needs — each model excels in different areas.
How does GPT-5.5 compare to o3 for coding?
SWE-bench Verified data is not available for both models. Check the detailed comparison charts above for other coding-related metrics.
Is GPT-5.5 cheaper than o3?
Yes, o3 is cheaper. GPT-5.5 costs $5.0/1M input and $30.0/1M output tokens. o3 costs $2.0/1M input and $8.0/1M output tokens.
Which is faster, GPT-5.5 or o3?
Output speed data is not available for both models. Check the speed section of the comparison above for available performance data.
What benchmarks does the GPT-5.5 vs o3 comparison cover?
This comparison covers 7 benchmarks including GPQA Diamond, Input Cost, Output Cost, Context Length, Cached Input Cost, Design Arena ELO, Website Arena ELO. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.