Last refreshed 2026-06-15. Next refresh: weekly.
Why use GPT-5.1 Codex on OpenRouter?
OpenRouter offers GPT-5.1 Codex with pay-as-you-go pricing at $1.25/1M input tokens. OpenRouter is a multi-provider LLM aggregator offering unified API access to 300+ models from all major labs and emerging providers, with automatic failover for reliability.
Compare GPT-5.1 Codex across 2 providers to find the best fit for your use caseSetup recipe
Docs fallbackUse the provider REST API or SDKCreate a provider API keymodel: openai/gpt-5.1-codexopenai/gpt-5.1-codexRequest example
openai/gpt-5.1-codex.Gotchas
- Use provider model ID "openai/gpt-5.1-codex", not the LLMReference slug "gpt-5.1-codex".
Compare GPT-5.1 Codex Across Providers
| Provider | Input (per 1M) | Output (per 1M) |
|---|---|---|
| OpenRouter | $1.25 | $10.00 |
| Vercel AI Gateway | $1.25 | $10.00 |
Pricing
| Type | Price (per 1M) |
|---|---|
| Input tokens | $1.25 |
| Output tokens | $10.00 |
| Image input | $1.00 |
Capabilities
About GPT-5.1 Codex
GPT-5.1-Codex is a coding-specialized version of GPT-5.1, optimized for software engineering and agentic coding workflows at 400K context.
FAQ
What does GPT-5.1 Codex cost on OpenRouter?
On OpenRouter, GPT-5.1 Codex costs $1.25 per 1M input tokens and $10 per 1M output tokens.
What is the context window for GPT-5.1 Codex on OpenRouter?
GPT-5.1 Codex supports a 400k token context window on OpenRouter.
How does OpenRouter compare to other GPT-5.1 Codex providers?
GPT-5.1 Codex is available from 2 providers. The cheapest input pricing is $1.25/1M tokens from OpenRouter.
What API model ID do I use for GPT-5.1 Codex on OpenRouter?
Use the model ID openai/gpt-5.1-codex when calling OpenRouter's API.
Who created GPT-5.1 Codex?
GPT-5.1 Codex was created by OpenAI as part of the GPT-5.1 model family.
Is GPT-5.1 Codex open source?
GPT-5.1 Codex is not open source; the seed data lists it as proprietary.