Compare · ModelsLive · 2 picked · head to head
GPT-5.5 Pro vs Step 3.5 Flash
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
GPT-5.5 Pro wins on 0/0 benchmarks
Not enough overlapping benchmarks to declare a winner yet · GPT-5.5 Pro · Step 3.5 Flash are still filling in scores.
Hype vs Reality
Attention vs performance
GPT-5.5 Pro
#1 by perf·no signal
Step 3.5 Flash
#9 by perf·#11 by attention
Best value
Step 3.5 Flash
459.8x better value than GPT-5.5 Pro
GPT-5.5 Pro
0.8 pts/$
$105.00/M
Step 3.5 Flash
384.5 pts/$
$0.20/M
Vendor risk
Mixed exposure
One or more vendors flagged
OpenAI
$840.0B·Tier 1
StepFun
$5.0B·Tier 1
Pricing · per 1M tokens · projected $/mo at 10M tokens
| Model | Input | Output | Context | Projected $/mo |
|---|---|---|---|---|
| $30.00 | $180.00 | 400K tokens (~200 books) | $675.00 | |
| $0.10 | $0.30 | 262K tokens (~131 books) | $1.50 |