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Available now on ModelsLab · Language Model

GPT 5.1GPT 5.1 Smarter Reasoning

Try GPT 5.1API Documentation
GPT 5.1

Unlock GPT 5.1 Power

Dual Modes

Instant Thinking Switch

Auto-routes queries to GPT 5.1 Instant for speed or Thinking for complex reasoning.

Adaptive Logic

Dynamic Reasoning Depth

Adjusts computation based on task complexity in GPT 5.1 model for efficient outputs.

Tone Control

Customizable Personalities

Shapes GPT 5.1 API responses with warmer style and precise instruction following.

Examples

See what GPT 5.1 can create

Copy any prompt below and try it yourself in the playground.

Code Debug

“Analyze this Python function for bugs, suggest fixes, and explain reasoning step-by-step using Thinking mode.”

Data Summary

“Summarize key trends from this sales dataset in a table format, highlight anomalies with adaptive reasoning.”

Workflow Plan

“Design an automated email triage system: outline steps, decision points, and integration code.”

Math Solver

“Solve this AIME-level math problem with full working, verify answer using high reasoning effort.”

For Developers

A few lines of code.
GPT 5.1. One Call.

ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed.

  • Serverless: scales to zero, scales to millions
  • Pay per token, no minimums
  • Python and JavaScript SDKs, plus REST API
API Documentation 
import requests


response = requests.post(
    "https://modelslab.com/api/v7/llm/chat/completions",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "",
  "model_id": ""
}
)
print(response.json())

FAQ

Common questions about GPT 5.1

Read the docs

GPT 5.1 is an LLM family with Instant mode for fast tasks and Thinking mode for complex reasoning. It features adaptive reasoning and automatic routing. Available via API with 400k context.

Adds dual modes, dynamic effort levels, and better tone controls. Reduces latency for automation while improving instruction adherence. Supports configurable reasoning effort.

Yes, excels in agentic coding with GPT-5.1-Codex-Max variant. Handles debugging, planning, and multi-step logic via Thinking mode. Outperforms on Codeforces benchmarks.

Instant for quick chats and low latency; Thinking for deeper analysis. Auto mode routes based on prompt complexity. Both use adaptive reasoning.

Supports 400,000 token context window and 128,000 output tokens. Ideal for extended workflows and data processing. Manages complex instructions reliably.

Offers enterprise-grade features like personalization presets and cost-efficient token use. Matches OpenAI capabilities via compatible LLM endpoint. Faster for automation tasks.

Ready to create?

Start generating with GPT 5.1 on ModelsLab.

Try GPT 5.1API Documentation