Compare · ModelsLive · 2 picked · head to head

Step 3.5 Flash vs GPT-5.4 Pro

Side by side · benchmarks, pricing, and signals you can act on.

Winner summary

Not enough overlapping benchmarks to declare a winner yet · Step 3.5 Flash · GPT-5.4 Pro are still filling in scores.

Hype vs Reality
Step 3.5 Flash
#9 by perf·#11 by attention
DESERVED
GPT-5.4 Pro
#26 by perf·no signal
QUIET
Best value
605.3x better value than GPT-5.4 Pro
Step 3.5 Flash
384.5 pts/$
$0.20/M
GPT-5.4 Pro
0.6 pts/$
$105.00/M
Vendor risk
One or more vendors flagged
stepfun logo
StepFun
$5.0B·Tier 1
Higher risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
stepfun logoStep 3.5 Flash$0.10$0.30262K tokens (~131 books)$1.50
OpenAI logoGPT-5.4 Pro$30.00$180.001.1M tokens (~525 books)$675.00