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GPT-5.1-Codex Pricing

OpenAI · openai-gpt-5-1-codex

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Input / 1M tokens

$1.25

Output / 1M tokens

$10.00

Context window

400k tokens

≈ 533 pages of text

Max output

128k tokens

What it costs in practice

Typical request (1,200 in + 400 out tokens)$0.0055

1,000 requests / month$5.50/mo 10,000 requests / month$55.00/mo 100,000 requests / month$550.00/mo

Estimate your own workloadOpens the calculator with GPT-5.1-Codex preloaded — adjust volume and token counts there.

Price history

List price per 1M tokens since we started tracking in Jun 2026. The lines are flat because the price hasn't changed since then.

What it excels at

Handles extended codebases and multi-file reasoning within a 400k-token context window and supports up to 128k output tokens per request.

The business tradeoff

Output pricing at $10 per million tokens increases cost for long generations; model name indicates possible specialization that may reduce generality versus standard GPT releases.

Cheaper from OpenAI

GPT-5.4 NanoOpenAI$0.0007/ typical request GPT-5.6 Luna ProOpenAI$0.0004/ typical request GPT-5.4 MiniOpenAI$0.0027/ typical request

Same tier from other providers

Claude Fable 5Anthropic$0.032/ typical request Qwen3.7 PlusQwen$0.0009/ typical request Grok 4.3xAI$0.0025/ typical request

Head-to-head

GPT-5.1-Codex vs Claude Fable 5 →GPT-5.1-Codex vs Qwen3.7 Plus →GPT-5.1-Codex vs Grok 4.3 →

Vendor list rates, as of Jul 26, 2026 · source: openrouter · per-request examples assume 1,200 input + 400 output tokens.