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GPT-5.1: Smarter, More Conversational Performance
Released on November 12, 2025 as part of the GPT-5 lineup, GPT-5.1 sits alongside GPT-5 and GPT-5 mini as the family's most conversational and adaptable model. Positioned as a versatile choice for coding and agentic workflows.
It introduces more natural dialogue abilities and configurable reasoning effort for flexible performance demands. These improvements make it well-suited for tasks that blend interaction and execution, such as coding assistance, automated agents, and complex task orchestration. It's ideal for teams building advanced development tools, intelligent agents, and reasoning-driven automation systems.
GPT-5.1: Key Specs
Below are GPT-5.1's main specs and how they translate into real-world behavior.
- Context Window - Up to 400,000 tokens: This expanded context capacity helps the model keep track of long discussions or sizeable documents, allowing it to maintain continuity across extended tasks without losing earlier information.
- Maximum Output Length - Up to 128,000 tokens: It can produce long, uninterrupted outputs, making it useful for generating full-length write-ups, thorough explanations, and complex multi-part content in a single response.
- Speed and Efficiency - Provides a reasonably fast response flow with no major delays. The model answers quickly enough to keep interactions smooth, supporting real-time tools and conversational use cases with only minimal waiting.
- Cost Efficiency - Priced at $1.25 / $10.00 per 1M tokens: This balanced cost structure makes it a practical option for teams that need consistent quality while managing ongoing operational expenses.
- Reasoning and Accuracy - Strong higher-tier reasoning capability: It performs well on layered logic, structured analysis, and tasks that require careful interpretation, offering more reliability than baseline models.
- Multimodal Capabilities - Handles text and images as input, responds in text: The model can interpret written material or visual content together, enabling more flexible queries such as analyzing screenshots or combining visual details with text prompts.
Compare GPT-5.1, GPT-5 mini, and GPT-5
A brief overview of how each model differs in power, speed, and use cases.
| Feature | GPT-5.1 | GPT-5 | GPT-5 mini |
|---|---|---|---|
| Knowledge Cutoff | Sep 30, 2024 | Sep 30, 2024 | May 31, 2024 |
| Context Window (Tokens) | 400,000 | 400,000 | 400,000 |
| Max Output Tokens | 128,000 | 128,000 | 128,000 |
| Input Modalities | Text, image | Text, image | Text, image |
| Output Modalities | Text | Text | Text |
| Latency (OpenRouter Data) | 3.80s | 7.10s | 4.84s |
| Speed | Very Fast (noticeably faster than GPT-5) | Medium (mid-tier in the GPT-5 series) | Faster than GPT-5 |
| Input / Output Cost per 1M Tokens | $1.25 / $10.00 | $1.25 / $10 | $0.25 / $2 |
| Reasoning Performance | Very High | Very High | High |
| Coding Performance (on SWE-bench Verified) | 76.30% | 74.90% | 59.80% |
| Best For | coding and agentic tasks with configurable reasoning and non-reasoning effort | coding, reasoning, and agentic tasks across domains | well-defined and lighter-weight reasoning tasks |
Source: OpenAI GPT-5.1 Documentation
Best Cases to Use GPT-5.1
GPT-5.1 is best for coding and agentic tasks that need flexible reasoning depth and reliable, consistent execution.
- For students and learners: Get clear explanations of coding concepts and reasoning steps, supporting deeper understanding of complex topics through structured, easy-to-follow breakdowns.
- For developers: Use GPT-5.1 to generate, debug, and refine code while adjusting reasoning depth for harder logic, helping streamline complex engineering workflows from start to finish.
- For businesses and teams: Create internal tools that depend on steady reasoning and accuracy, from document processing to structured decision workflows that need consistent results.
- For product teams and app builders: Build reliable agents that follow instructions, complete multi-step actions, and adapt to context, reducing manual oversight in key product experiences.
- For operations and support workflows: Automate routine tasks, triage issues, and guide multi-step procedures, improving response quality and reducing repetitive manual effort.
- For content and marketing helpers: Turn complex ideas into clear, structured messaging and refine drafts with strong reasoning support, ensuring accuracy while speeding up content production workflows.
How to Access GPT-5.1
Accessing GPT-5.1 is simple, and you can choose the option that best fits your workflow.
1. OpenAI API
You can use GPT-5.1 directly through the official OpenAI API. This requires an API key and an active usage or billing plan. It's ideal for developers who want full control and need to integrate the model into apps, tools, or automated systems.
2. EssayDone AI Chat
If you prefer instant access without setup, region limits, or API configuration, you can use GPT-5.1 through EssayDone AI Chat.
It delivers the same core model output as the official API but in a simple, user-friendly interface-perfect for students, writers, and professionals who want to start using the model right away.
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FAQ
Here are some frequently asked questions about GPT-5.1.
Yes. GPT-5.1 offers higher-than-average reasoning performance, supported by a reasoning level roughly equivalent to a rating of 4. It is well suited for complex logic, structured analysis, and advanced task planning.
GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. It is positioned as a higher-tier model within the GPT-5 family.
GPT-5.1 is optimized for coding, automation, and agent-style workflows that require both reasoning and non-reasoning execution. It is ideal for tasks that need adaptable thinking and reliable step-by-step logic.
GPT-5.1 accepts text and image inputs and produces text outputs. It handles multimodal tasks effectively, offering strong performance in text-and-image workflows, though its output channel remains text-only.
GPT-5.1 offers stronger reasoning and more adaptable task handling than GPT-5 mini, making it a more capable mid-to-high tier option. Compared to full GPT-5, it is more efficient while still delivering robust performance across coding and agentic tasks.
Using GPT-5.1 in EssayDone AI Chat requires no API key, has no daily message limits, and is available with no geographical restrictions. You can access ChatGPT and many other AI models on one platform with a single payment, at a more affordable price.