The strongest choice for serious software engineering work, provided you can absorb the output-side pricing.
95
Coding
55
Writing
72
Research
0
Images
48
Value
85
Long Context
Use this when
Professional developers and engineering teams working with complex, multi-file codebases who need accurate code generation, debugging, and architectural reasoning.
Skip this if
Avoid if your primary needs are creative writing, image generation, or high-volume automated code tasks where output costs will compound rapidly.
Pricing
$1.25/1M in
$10.00/1M out
→0%since May 2026
Context
400k tokens
Speed
Balanced
GPT-5.1-Codex-Maxspecs & pricing
Verified Sep 4, 2026 against the AI Gateway catalog
Output cost of $10/1M tokens is the key budget consideration — input is competitively priced but output costs mirror GPT-4 Turbo-tier pricing. Best paired with a cheaper model for lightweight or repetitive coding subtasks. Context window of 400K is well-suited to monorepo analysis but verify token limits on your deployment tier.
Best-in-class code generation and debugging across major languages, outperforming Claude Sonnet 4.6 on complex multi-file refactoring tasks
400K context window allows ingestion of entire repositories, making whole-codebase understanding and refactoring practical
Strong reasoning over technical specifications, API documentation, and system design problems
Competitive pricing at $1.25/$10 per 1M tokens — cheaper input cost than GPT-4o's successor-tier competitors
Weaknesses
Output cost of $10/1M tokens adds up quickly in high-throughput code generation pipelines, making it expensive at scale compared to budget alternatives like GPT-4o-mini
Not optimized for creative writing, marketing copy, or general conversational use where Claude Sonnet 4.6 or Gemini 3.1 Pro perform comparably at lower cost
No native image generation capability despite the Codex-Max branding implying multimedia depth
Real-world use cases
What people actually use GPT-5.1-Codex-Max for.
Ingesting an entire Node.js monorepo (200K+ tokens) and generating a migration plan to TypeScript with file-by-file refactoring suggestions
Debugging a complex race condition in a distributed Go service by analyzing multiple interconnected files simultaneously
Generating a production-ready REST API with authentication, error handling, and test coverage from a detailed technical specification
How GPT-5.1-Codex-Max compares
The nearest models people weigh against it, and what actually separates them.
vs GPT-4 Turbo — Against GPT-4 Turbo (OpenAI), GPT-5.1-Codex-Max runs about 72% cheaper per token and takes 3.1x the context. Take GPT-5.1-Codex-Max unless you specifically need what GPT-4 Turbo does better.
vs GPT-4 Turbo (older v1106) — Against GPT-4 Turbo (older v1106) (OpenAI), GPT-5.1-Codex-Max runs about 72% cheaper per token and takes 3.1x the context. Take GPT-5.1-Codex-Max unless you specifically need what GPT-4 Turbo (older v1106) does better.
vs GPT-4 Turbo Preview — Against GPT-4 Turbo Preview (OpenAI), GPT-5.1-Codex-Max runs about 72% cheaper per token and takes 3.1x the context. Take GPT-5.1-Codex-Max unless you specifically need what GPT-4 Turbo Preview does better.
Price History
GPT-5.1-Codex-Max pricing over time
→0% since May 30
90 data points · tracked daily since May 30, 2026
Ready to try it?
Start using GPT-5.1-Codex-Max
Professional developers and engineering teams working with complex, multi-file codebases who need accurate code generation, debugging, and architectural reasoning.. Start free — no card required.
GPT-4 Turbo is OpenAI's high-capability flagship model featuring a 128K context window, trained on data up to April 2024. It delivers strong reasoning, coding, and instruction-following across complex tasks.
Verdict
A capable but aging flagship that has been outpaced by cheaper, faster successors in OpenAI's own lineup.
Quality score
75%
Pricing
$10.00/1M in
$30.00/1M out
Speed
Balanced
3/5 speed
Context
128k tokens
GPT-4 Turbo is available via the OpenAI API. It has largely been succeeded by GPT-4o, which is faster, supports vision natively, and is cheaper. Organizations should evaluate whether migrating to GPT-4o or o3 makes more sense before building new workflows on this model.
GPT-4 Turbo (v1106) is an older snapshot of OpenAI's flagship GPT-4 Turbo model released in November 2023, offering a 128K context window with strong general-purpose reasoning and instruction-following capabilities. It predates later GPT-4 Turbo updates and GPT-4o, making it a legacy choice for workflows locked to this specific version.
Verdict
A reliable but outdated GPT-4 snapshot that only makes sense when version pinning is a hard requirement.
Quality score
66%
Pricing
$10.00/1M in
$30.00/1M out
Speed
Balanced
3/5 speed
Context
128k tokens
This is a pinned model snapshot (v1106) and will not receive capability updates. OpenAI may deprecate older snapshots over time. Knowledge cutoff is April 2023. Not recommended for new deployments given the superior cost-performance of GPT-4o and GPT-4.1.
Legacy128K ContextPinned SnapshotGPT-4Premium
Best for
Teams requiring a pinned, stable version of GPT-4 Turbo for reproducible outputs in long-document analysis or complex instruction pipelines.
GPT-4 Turbo Preview is an early access version of GPT-4 Turbo, OpenAI's then-flagship model featuring a 128K context window and knowledge improvements over the original GPT-4. It was designed to deliver GPT-4-class reasoning at reduced cost compared to the original GPT-4.
Verdict
A once-capable flagship now overshadowed by faster, cheaper, and smarter successors.
Quality score
67%
Pricing
$10.00/1M in
$30.00/1M out
Speed
Balanced
3/5 speed
Context
128k tokens
This is a 'preview' variant that OpenAI has largely deprecated in favor of gpt-4-turbo and gpt-4o. The endpoint may be retired or redirected by OpenAI without notice. Check the OpenAI model deprecation schedule before building production applications on this model.
GPT-4Long ContextLegacyPremiumOpenAI
Best for
Complex multi-step reasoning, long-document analysis, and professional writing tasks requiring strong instruction-following.
Pricing moves, ranking shifts, and capability updates.
New ModelMar 27, 2026
OpenAI: GPT-5.1-Codex-Max — added to UseRightAI
OpenAI: GPT-5.1-Codex-Max (OpenAI) is now indexed. It supersedes GPT-4o. The strongest choice for serious software engineering work, provided you can absorb the output-side pricing.
GPT-5.1-Codex-Max costs $1.25 per million input tokens and $10 per million output tokens on the API, with cached input at $0.125 per million. A month of 10M input and 2M output tokens runs about $32.50 at list price, before any batch or caching discounts.
What is the context window of GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max has a 400k tokens context window, with up to 128k tokens of output per response. That is the total of prompt plus response the model can hold in one request.
What is the knowledge cutoff of GPT-5.1-Codex-Max?
GPT-5.1-Codex-Max's training data runs through September 30, 2024, and the model was released on November 19, 2025. For anything after that date it needs web search or documents in the prompt.
What is GPT-5.1-Codex-Max best for?
GPT-5.1-Codex-Max is best for professional developers and engineering teams working with complex, multi-file codebases who need accurate code generation, debugging, and architectural reasoning.. It is a strong fit when that workflow matters more than the tradeoffs around balanced pricing and balanced speed.
When should I avoid GPT-5.1-Codex-Max?
Avoid if your primary needs are creative writing, image generation, or high-volume automated code tasks where output costs will compound rapidly.
What is a cheaper alternative to GPT-5.1-Codex-Max?
GPT-4 Turbo (OpenAI) at $10.00/1M/1M input against GPT-5.1-Codex-Max's $1.25/1M/1M. A capable but aging flagship that has been outpaced by cheaper, faster successors in OpenAI's own lineup. Compare it first if GPT-5.1-Codex-Max's pricing is the thing stopping you.
What is a faster alternative to GPT-5.1-Codex-Max?
GPT-4 Turbo (older v1106) — balanced against GPT-5.1-Codex-Max's balanced, with 128k tokens of context. Worth the swap when response time is what your users notice rather than the last few points of reasoning depth.
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