Compare · ModelsLive · 2 picked · head to head

GPT-5.1-Codex vs GPT-5.5 Pro

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

Winner summary

Not enough overlapping benchmarks to declare a winner yet · GPT-5.1-Codex · GPT-5.5 Pro are still filling in scores.

Hype vs Reality
GPT-5.1-Codex
#23 by perf·no signal
QUIET
GPT-5.5 Pro
#1 by perf·no signal
QUIET
Best value
14.6x better value than GPT-5.5 Pro
GPT-5.1-Codex
12.2 pts/$
$5.63/M
GPT-5.5 Pro
0.8 pts/$
$105.00/M
Vendor risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
OpenAI logo
OpenAI
$840.0B·Tier 1
Medium risk
Pricing · per 1M tokens · projected $/mo at 10M tokens
ModelInputOutputContextProjected $/mo
OpenAI logoGPT-5.1-Codex$1.25$10.00400K tokens (~200 books)$34.38
OpenAI logoGPT-5.5 Pro$30.00$180.00400K tokens (~200 books)$675.00