GPT-5.1 Codex
azure The API that serves this model and sets the prices shown here. gpt-5.1-codex The model identifier to send in API requests. LLM Generates text from a prompt, so it can be compared with other LLMs on price and capability. Large The most capable general-purpose tier of a model family.Provider: azure
Knowledge cutoff: September 2024
Nothing to act on today. The cost is the checking: someone has to remember to look again next month, and the month after. Coolhand watches this model for you and automatically updates your agents to the most compatible replacement the moment a retirement is announced — one less thing on your list, permanently.
Sticker prices & cost-per-token
List rates as published by azure, before any volume or enterprise discounts.
$1.25
$10.00
400,000 tokens
128,000
tokens per response (includes reasoning tokens)
Closed weights
$0.125
Get this data free
Want to stay updated on price changes on this model? Pull this data free (no API key required) here:
curl "https://coolhandlabs.com/api/v2/inference_apis?q%5Bmodel_eq%5D=gpt-5.1-codex&q%5Bsource_api_eq%5D=azure"Pricing History
| Effective | Price |
|---|---|
| Sep 21, 2026 – present | Input cost: $1.25 / 1M, Output cost: $10.00 / 1M, Cached input cost: $0.125 / 1M, Cache creation cost: $0.00 / 1M, 5-minute cache write cost: $0.00 / 1M, 1-hour cache write cost: $0.00 / 1M, Reasoning output cost: $0.00 / 1M, Cache storage cost: $0.00 / 1M/hr |
| Aug 16, 2026 – Sep 21, 2026 | Input cost: $1.25 / 1M, Output cost: $10.00 / 1M, Cached input cost: $0.125 / 1M, Cache creation cost: $0.00 / 1M, 5-minute cache write cost: $0.00 / 1M, 1-hour cache write cost: $0.00 / 1M, Reasoning output cost: $0.00 / 1M, Cache storage cost: $0.00 / 1M/hr |
History
Last change detected September 21, 2026 (about 1 month ago) by an automated scan.
| Date | Changed by | What changed |
|---|---|---|
| Aug 16, 2026 | Unknown | Initial record created |
Source
https://models.dev/api.json (models.dev provider 'azure', bulk import 2026-08-13)Comparable models
No comparable models identified yet.
Reliability
No reliability incidents recorded in the last 90 days.
Frequently asked questions
GPT-5.1 Codex (azure) costs $1.25 per 1M input tokens and $10.00 per 1M output tokens, as last published by azure.
GPT-5.1 Codex has a context window of 400,000 tokens (the maximum combined input and output it can handle in a single request).
GPT-5.1 Codex sits in the large size tier. Size tiers run from micro (small enough to run on a device) through small, medium and large to extra large (frontier flagships), and are assigned from the model's family, naming and limits rather than its price.
GPT-5.1 Codex can generate up to 128,000 tokens in a single response. Reasoning (thinking) tokens count toward this limit.
GPT-5.1 Codex's training data runs through September 2024, so it may not know about later events. Coolhand records the cutoff at month precision, since providers often publish only the month.
GPT-5.1 Codex accepts audio, image, and text as input and produces audio, image, and text as output, as recorded in the Coolhand catalog.
No — the weights of GPT-5.1 Codex have not been released, so it is only available through hosted APIs.
No, GPT-5.1 Codex is currently active with no announced deprecation date.
Call GET https://coolhandlabs.com/api/v2/inference_apis?q[source_api_eq]=azure&q[model_eq]=gpt-5.1-codex — free, no API key required, and scoped to just this model since source_api and model together are unique. See https://coolhandlabs.com/docs for the full REST API reference.
Coolhand also tracks GPT-5.4, GPT-5.4 Mini, GPT-5.4 Nano, GPT-5.5, GPT-5.6 Luna, and GPT-5.6 Terra from azure. Some may already be deprecated, so check each model's status alongside its current pricing.
| Model | Input cost | Output cost | Context window | Max output tokens | Status |
|---|---|---|---|---|---|
| GPT-5.4 | $2.50/1M $0.0000025000 | $15.00/1M $0.0000150000 | 1,050,000 | 128,000 | Active |
| GPT-5.4 Mini | $0.75/1M $0.0000007500 | $4.50/1M $0.0000045000 | 400,000 | 128,000 | Active |
| GPT-5.4 Nano | $0.20/1M $0.0000002000 | $1.25/1M $0.0000012500 | 400,000 | 128,000 | Active |
| GPT-5.5 | $5.00/1M $0.0000050000 | $30.00/1M $0.0000300000 | 1,050,000 | 128,000 | Active |
| GPT-5.6 Luna | $0.20/1M $0.0000002000 | $1.20/1M $0.0000012000 | 1,050,000 | 128,000 | Active |
| GPT-5.6 Terra | $2.00/1M $0.0000020000 | $12.00/1M $0.0000120000 | 1,050,000 | 128,000 | Active |
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