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GPT-5.1-Codex vs GPT 5.5 Pro

GPT-5.1-Codex is cheaper on output tokens, while GPT 5.5 Pro offers a larger context window. Choose GPT-5.1-Codex or GPT 5.5 Pro based on the trade-off between cost, context, and the benchmarks that matter for your use case.

SpecGPT-5.1-CodexGPT 5.5 Pro
ProviderVercel AI GatewayVercel AI Gateway
Input / 1M tokens$1.25$30.00
Output / 1M tokens$10.00$180.00
Context window400K1M
Parameters
Open weightsNoNo
ReleasedNov 2025Apr 2026

FAQ

Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.