GPT-5.1-Codex vs Gemini 3.5 Flash
74.6 overall · $3.38 / 1M
// openai
GPT-5.1-Codex
openai/gpt-5.1-codex
reasoningtool callingimage inputprompt caching
GPT-5.1-Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens with a 400K-token context window.
A reasoning, tool-calling model from openai, released Nov 13, 2025. LiveBench hasn't published a run for it, so this page carries measured price and specs only — no benchmark numbers.
- Input / 1M
- $1.25
- Output / 1M
- $10.00
- Context
- 400K
- LiveBench overall
- Not evaluated
Specs and pricing
| Input price USD per 1M prompt tokens | $1.25 |
|---|---|
| Output price USD per 1M completion tokens, reasoning included | $10.00 |
| Blended price 3:1 input:output — #64 most expensive of 343 listed models | $3.44 |
| Cached input read Blank means not priced separately — not free | $0.130 |
| Cache write | — |
| Context window | 400,000 tokens |
| Max output | 128,000 tokens |
| Input modalities | text, image |
| Tool calling | Yes |
| Extended reasoning | Yes |
| Knowledge cutoff | — |
| Listed | Nov 13, 2025 |
What GPT-5.1-Codex costs to run
Monthly list cost across five workload shapes, using the published cached-input rate where there is one. A floor, not a quote — batch discounts and cache writes aren't included.
| Workload | Per month |
|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $1,019/mo |
| RAG assistant 8K in / 600 out × 100K requests | $1,152/mo |
| Coding agent 40K in / 4K out × 20K requests | $1,173/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $1,944/mo |
| Bulk classification 500 in / 20 out × 5M requests | $3,565/mo |
Compare GPT-5.1-Codex with
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GPT-5.1-Codex FAQ
How much does GPT-5.1-Codex cost?
GPT-5.1-Codex lists at $1.25 per 1M input tokens and $10.00 per 1M output tokens, with cached input reads at $0.130 per 1M. A RAG assistant handling 100K requests a month (8K tokens in, 600 out) comes to about $1,152 at list price.
What is the context window of GPT-5.1-Codex?
GPT-5.1-Codex accepts up to 400,000 tokens of context and can return up to 128,000 output tokens per response.
Does GPT-5.1-Codex support tool calling?
Yes — GPT-5.1-Codex supports tool (function) calling and exposes extended reasoning. It accepts text, image input.
How does GPT-5.1-Codex score on benchmarks?
LiveBench has not published a run for GPT-5.1-Codex yet. Until it does, compare it on price and specs, or run your own evaluation on your own tasks.
What is the API model ID for GPT-5.1-Codex?
On OpenRouter the model ID is "openai/gpt-5.1-codex". It was listed on Nov 13, 2025.
More from openai
How these numbers are produced
- Price and specs — provider list data from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
- Scores and ranks — LiveBench release 2026-06-25. Ranks count only models that have a published run; a blank means “not evaluated”, never “bad”.
- Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.