OpenAI: GPT-5.1 Codex Max

Coding-optimized GPT model for repository edits, reviews, and agentic software work

Source-linked gpt-codex Closed weights Released 2025-11-13

API record Report

InputT

OutputT

Input price$1.1/M

Output price$9/M

Context400K

Max output128K

Providers18

Inference availability

Providers

Provider-specific identifiers, limits, and listed prices per million tokens. Every row links back to the provider's own documentation.

Report a price

Providers offering GPT-5.1 Codex Max
Provider	Provider model ID	Context	Max output	Input	Output	Cache read	Capabilities	Docs
Requesty	`openai/gpt-5.1-codex-max`	400K	128K	$1.1	$9	$0.11	ReasoningToolsJSON	Docs ↗
Poe	`openai/gpt-5.1-codex-max`	400K	128K	$1.1	$9	$0.11	ReasoningTools	Docs ↗
Vercel AI Gateway	`openai/gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Vivgrid	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
DigitalOcean	`openai-gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
OpenAI	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
OrcaRouter	`openai/gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Azure	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
OpenCode	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Kilo Gateway	`openai/gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
OpenRouter	`openai/gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Neon	`gpt-5-1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Ofox	`openai/gpt-5.1-codex-max`	256K	128K	$1.25	$10	$0.13	ReasoningToolsJSON	Docs ↗
Eden AI	`azure/gpt-5.1-codex-max`	272K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Azure Cognitive Services	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	$0.125	ReasoningToolsJSON	Docs ↗
Abacus	`gpt-5.1-codex-max`	400K	128K	$1.25	$10	—	ReasoningToolsJSON	Docs ↗
NanoGPT	`openai/gpt-5.1-codex-max`	400K	128K	$2.5	$20	$0.25	ReasoningToolsJSON	Docs ↗
AI/ML API	`openai/gpt-5.1-codex-max`	400K	128K	$2.645	$21.16	$0.265	ReasoningToolsJSON	Docs ↗

Capability badges appear only where the provider catalog explicitly lists support. A blank cell means the source is silent, not that the feature is absent.

Listed rates

Price across providers

Input price per million tokens as published by each provider. Bars are drawn from listed rates only — no traffic weighting, since the catalog observes no requests.

Lowest input $1.1/M

Across 18 priced providers

Median input $1.25/M

Midpoint of listed rates

Highest input $2.645/M

2.4× the lowest listed rate

Output range $9 – $21.16

Per million output tokens

Requesty $1.1/M

Poe $1.1/M

Vercel AI Gateway $1.25/M

Vivgrid $1.25/M

DigitalOcean $1.25/M

OpenAI $1.25/M

OrcaRouter $1.25/M

Azure $1.25/M

OpenCode $1.25/M

Kilo Gateway $1.25/M

OpenRouter $1.25/M

Neon $1.25/M

Ofox $1.25/M

Eden AI $1.25/M

Azure Cognitive Services $1.25/M

Abacus $1.25/M

NanoGPT $2.5/M

AI/ML API $2.645/M

Cost calculator

Estimate a workload

Provider Input tokens 1,000,000 Output tokens 250,000 Cached input 0%

$0.00

Excludes taxes, non-token charges, and tiered discounts.

2 providers list the identical $1.1 input rate, so price alone will not separate them — compare context limits, max output, and capabilities above.

Context limits also differ by provider, from 256K to 400K tokens. Compare the provider table above before choosing on price alone.

Specification

Capabilities

Recorded from the source catalog and provider listings.

✓ Reasoning Yes

✓ Tool calling Yes

✓ Structured output Yes

✓ Attachments Yes

✓ Vision input Yes

× Open weights No

Creator: OpenAI
Model family: gpt-codex
Knowledge cutoff: 2024-09-30
License: Not documented
Release date: 2025-11-13
Model ID: openai/gpt-5.1-codex-max

Published evaluations

Benchmarks

Every result stays attached to its source, version, metric and harness. Scores from different versions are never merged, and the profile below plots each benchmark against its own population rather than on a shared scale.

Benchmark registry

No published benchmark results

ModelBench does not infer quality from price, context size, or model name. When a source publishes a comparable result, it appears here with its version and link.

Read the methodology

Catalog activity

Change log

Field-level changes detected between successful source imports.

Full change log

Oct 24, 2026Price Completion10.0 → 9.0

Oct 24, 2026Price Prompt1.25 → 1.1

Oct 24, 2026Price Completion9.0 → 10.0

Oct 24, 2026Price Prompt1.1 → 1.25

Oct 24, 2026Price Completion10.0 → 9.0

Oct 24, 2026Price Prompt1.25 → 1.1

Oct 24, 2026Price Completion9.0 → 10.0

Oct 24, 2026Price Prompt1.1 → 1.25

Oct 24, 2026Price Completion10.0 → 9.0

Oct 24, 2026Price Prompt1.25 → 1.1

Provenance

Sources & verification

Every figure on this page traces back to one of these records.

Methodology

Last verified: Oct 24, 2026
Status: Source-linked
Confidence: Medium
Catalog source: Models.dev

Public API

Use this record

Fetch the complete source-linked model record. No key, no account, no rate-limited tier.

API documentation

Endpoint

GET https://modelbench.lol/api/v1/models/openai/gpt-5.1-codex-max

curl

curl "https://modelbench.lol/api/v1/models/openai/gpt-5.1-codex-max"

Common questions

Frequently asked questions

Answered directly from the stored record — nothing here is generated beyond the catalog's own fields.

What is GPT-5.1 Codex Max?

Coding-optimized GPT model for repository edits, reviews, and agentic software work. It is published by OpenAI and catalogued here from Models.dev.

How much does GPT-5.1 Codex Max cost?

Listed input pricing starts at $1.1 per million tokens from Requesty, rising to $2.645 across 18 listed providers.

What is the context length of GPT-5.1 Codex Max?

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

Does GPT-5.1 Codex Max support tool calling and structured output?

Provider catalogs list support for tool calling, structured output, reasoning, and image input.

Which providers serve GPT-5.1 Codex Max?

18 providers list this model: Requesty, Poe, Vercel AI Gateway, Vivgrid, DigitalOcean, OpenAI and 12 more.

Are the weights for GPT-5.1 Codex Max open?

No. This model is served through hosted APIs only.

When was GPT-5.1 Codex Max released?

The catalog records a release date of 2025-11-13, last verified Oct 24, 2026.

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