GPT-5.1 vs GPT-5 Pro
Compare pricing, context windows, and strengths for GPT-5.1 by OpenAI and GPT-5 Pro by OpenAI - and see how to put either to work in Appaca.
GPT-5.1
Flagship model for coding, reasoning, and agentic tasks with adjustable reasoning depth and multimodal input/output.
View GPT-5.1GPT-5 Pro
A premium GPT-5 variant that uses more compute to deliver consistently smarter, more precise reasoning for the toughest problems.
View GPT-5 ProGPT-5.1 vs GPT-5 Pro at a glance
Specs and pricing side by side, from the Appaca AI models directory.
| Spec | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Model type | Text | Text |
| Context window | 400K tokens | 400K tokens |
| Input price | $1.25 / 1M tokens | $15 / 1M tokens |
| Output price | $10 / 1M tokens | $120 / 1M tokens |
| Status | Current | Current |
How GPT-5.1 and GPT-5 Pro differ
What the numbers mean in practice when choosing between GPT-5.1 and GPT-5 Pro.
-
GPT-5.1 is 92% cheaper on input tokens ($1.25 vs $15 per million), which adds up quickly in document-heavy workloads.
-
GPT-5.1 is 92% cheaper on output tokens ($10 vs $120 per million) - the bigger factor for tools that generate long documents.
-
Both models offer the same 400K tokens context window.
Strengths side by side
Where each model shines, according to benchmarks and provider positioning.
GPT-5.1
1. Configurable Reasoning for Agentic Tasks
- Built to excel in autonomous or semi-autonomous coding workflows, with adjustable reasoning effort for planning, refactoring and debugging.
2. Fast Multi-Modal Input with Large Output
- Accepts both text and image inputs while producing text outputs.
- Offers up to 128 k output tokens, allowing long responses and code generation across multiple files.
3. Large Context & Knowledge Cut-Off
- 400 k token context window supports processing large codebases or documents.
- Knowledge cut-off of Sep 30 2024 ensures familiarity with recent tools and frameworks.
4. Reasoning Token Support
- Provides explicit support for reasoning tokens, enabling developers to fine-tune the balance between reasoning depth and speed.
GPT-5 Pro
1. Highest reasoning quality in the GPT-5 family
- Uses significantly more compute to "think harder" before responding.
- Designed for the toughest reasoning tasks where answer quality matters more than speed.
- Produces more precise, reliable, and detailed outputs than standard GPT-5.
2. Advanced multi-turn reasoning via Responses API
- Available only in the Responses API to support:
- Multi-turn internal model interactions before returning a reply.
- Advanced control patterns (e.g., background mode for long-running jobs).
- Ideal for complex workflows, deep planning, and multi-step analysis.
3. Configured for maximum effort by default
- Always runs with reasoning.effort: 'high' (no lower-effort mode).
- Prioritizes depth and correctness over latency and cost.
4. Multimodal input
- Accepts text + image as input.
- Outputs text, with strong instruction-following and analysis capabilities.
5. Tooling and ecosystem integration
- Supports Web Search, File Search, and Image Generation (as tools).
- Supports MCP and other Responses API tooling patterns.
- Does not support Code Interpreter and does not support Computer Use, keeping focus on pure reasoning + tools.
Use GPT-5.1 or GPT-5 Pro - or both
Appaca is the AI workspace for operators. Build internal tools and AI co-workers powered by GPT-5.1 or GPT-5 Pro - connected to your real data and ready for your whole team. No code, no deployment.
Describe it, and it's built
Tell the Appaca agent the internal tool you need and it builds a working app powered by GPT-5.1 or GPT-5 Pro. No code, no API keys, no deployment.
Switch models without rebuilding
Start on GPT-5.1, test the same tool on GPT-5 Pro, and keep whichever performs better - the rest of your app stays exactly as it is.
Automated for the whole team
Schedule tools to run on autopilot - daily digests, weekly reports, real-time triggers - and share them with your whole team from one workspace.
Describe it, and it's built
Tell the Appaca agent what your team needs and it builds a working app powered by GPT-5.1 or GPT-5 Pro - connected to the tools you already use.
Related comparisons
See how GPT-5.1 and GPT-5 Pro stack up against other models in the directory.
FAQs
GPT-5.1 is generally cheaper: $1.25 input / $10 output per million tokens, versus $15 / $120 for GPT-5 Pro. Actual cost depends on how many tokens your workload reads and writes.
They are equal: both GPT-5.1 and GPT-5 Pro support a 400K tokens context window.
It depends on the job. Compare the pricing, context window, and strengths above against your workload - and remember the choice isn't permanent. In Appaca you can build a tool on GPT-5.1, test the same tool on GPT-5 Pro, and switch at any time without rebuilding anything.
Yes. Appaca is a no-code AI workspace: describe the internal tool your team needs and the Appaca agent builds it as a working app powered by GPT-5.1, GPT-5 Pro, or any other model in the directory - with a built-in database, team access, and integrations. No API keys to wire up and nothing to deploy.
Build AI tools with GPT-5.1 or GPT-5 Pro
Describe the tool your team needs and get a working app powered by the model you choose - with a built-in database, team access, and integrations. No code, no deployment.