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GPT-5.1-Codex

OpenAIFirst listed Jul 2026
VisionTool useReasoningPrompt cachingStructured outputWeb search
Compare GPT-5.1-CodexCount tokens for GPT-5.1-Codex
Context
400K
Max output
128K
Serving providers
2
Cheapest input
$1.25 /1M
On-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments (committed-use discounts, provisioned throughput, negotiated rates) can be materially lower. An OpenRouter routed quote is the price of whichever upstream provider OpenRouter prefers today, so it moves day to day.

Benchmarks

independent evaluations · source: Artificial Analysis
Speed & latency
Output speed
126 t/s
tokens / second
Time to first token
11.40s
latency
Headline indices
Intelligence Index
23.7
of 100
Individual benchmarks · click a row for effort variants
BenchmarkBest scoreEffortCost / task
CritPt6%default—
GPQA Diamond86%default—
Humanity's Last Exam26%default—
IFBench70%default—
LiveCodeBench85%default—
Long-Context Reasoning69%default—
MMLU-ProFrozen Aug 18, 202686%default—
MMMU-Pro72%default—
Omniscience-6.5default—
Omniscience Accuracy0.4default—
Omniscience Non Hallucination0.2default—
SciCodeArtificial Analysis did not report this score in its latest run on Oct 14, 202640%——
TerminalBench Hard35%default—
τ²-bench83%default—
Artificial Analysis last published scores for this benchmark on Aug 18, 2026. Scores here are frozen at that date, and models released since are not on it.

Pricing by serving provider

standard tier · per 1M tokens · click a provider to expand
Serving providerInput /1MOutput /1MEndpoints
OpenRouterRouted quote$1.25$10.001
Standardopenai/gpt-5.1-codex
ComponentUnitStandard
Text cached in/1M tok$0.13
Text input/1M tok$1.25
Text output/1M tok$10.00
VercelRouted quoteVercel reseller quote$1.25$10.001

Price history

OpenRouter routed quote

OpenRouter's price is a routed quote. It moves with whichever upstream route OpenRouter prefers that day, so we do not track it as a price history.

Cost calculator

estimate your monthly spend on this model
$1,050
estimated / month

Model IDs

copy the exact identifier for your platform
openai/gpt-5.1-codexopenai/gpt-5.1-codex

Frequently asked questions

GPT-5.1-Codex pricing, context and availability

How much does GPT-5.1-Codex cost?

GPT-5.1-Codex costs $1.25 per 1M input tokens as an OpenRouter routed quote, and $10.00 per 1M output tokens as an OpenRouter routed quote. An OpenRouter routed quote is the price of whichever upstream provider OpenRouter prefers today, so it moves day to day.

What is the context window of GPT-5.1-Codex?

GPT-5.1-Codex accepts up to 400K tokens of context and can return up to 128K output tokens.

Which providers serve GPT-5.1-Codex?

GPT-5.1-Codex is available from 2 serving providers, each with its own pricing and model ID. OpenRouter is currently the cheapest, as a routed quote.

What can GPT-5.1-Codex do?

GPT-5.1-Codex supports image input (vision), tool use, reasoning, prompt caching, structured output and web search.

Other OpenAI models

compare pricing across the OpenAI lineup
gpt-oss-120b$0.03/1M · 23 providersgpt-oss-20b$0.0145/1M · 15 providersGPT-5 Mini$0.25/1M · 9 providersGPT-5$1.25/1M · 9 providersGPT-5 Nano$0.05/1M · 8 providersGPT-5.6 Luna$0.20/1M · 7 providersGPT-5.6 Terra$2.00/1M · 7 providersGPT-4o-mini$0.15/1M · 6 providers
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026

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