GPT-5.5 is the stronger all-rounder.
Scores updated · 4 tests both models report · How we compare
Where each one wins
Tests won in each of the three areas where both have results. Each piece is one test, so a longer bar means more evidence; grey means the two scored within a point of each other.
Coding, reasoning and images and charts rest on a single test each.
What it costs
Prices per million tokens, roughly 750,000 words. The bars show the cost of a million tokens read plus a million written.
Every test, side by side
All 4 tests both models report. The winning score is in its model's colour; marks a score checked independently.
Images and chartsGPT-5.5
- LMArena · VisionGPT-5.5 by 29 rating points12921263+29 rating
Other results1 test, not counted
Tests outside the eight areas. They are not counted above: several are summary scores built from other tests, or the same test under another name.
- Finance Agent v2GPT-5.5 by 23.351.828.5+23.3
Questions people ask
Which is better, GPT-5.5 or Grok 4.20 (Beta Reasoning)?
GPT-5.5 wins two of the three areas where both have results: coding and images and charts. Grok 4.20 (Beta Reasoning) wins none. They are level on reasoning.
Which is better for coding?
GPT-5.5. It wins the one coding test both models report.
How do you compare the two?
We use the 4 benchmark tests both models have published scores on. The verdict counts the 3 tests in the eight capability areas, and a gap under one point (ten on rating-style scales) counts as a tie. The other 1 are listed but not counted, because several are summary scores or repeat a test. Each score is the one shown on the model's own page.