OpenAI
GPT 5.1 Chat Latest
Chat
The gpt 5.1 chat api is OpenAI’s flagship frontier model. It combines high-velocity gpt conversation with deep reasoning. Use this api for multi-step planning, native video ingestion, and complex 5.1 coding tasks across 256k context tokens.

Modalities

Input: TextInput: ImageInput: Document
Output: Text

API Usage Examples
curl --request POST "https://gptproto.com/v1/chat/completions" \
  --header "Authorization: Bearer $GPTPROTO_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "model": "gpt-5.1-chat-latest",
    "messages": [
      {
        "role": "user",
        "content": "Hello"
      }
    ]
  }'
GPT 5.1 Chat Latest pricing

Estimate a request with real work scenarios. GPTProto token pricing is 20% below official rates.

Cost calculator

Multi-turn agent with cached context.
$1 / 1M$0.0015
$8 / 1M$0.0064
$0.1 / 1M$0.0003
$0.1 / 1M$0.0025
Cost per request$0.0107

Top up

GPTProto vs official pricing.
Requests
You pay
20% off
$100
You receive$100.00

Save$24.99 (20%)vs OpenAI

gpt 5.1 chat api Features

Core technical advantages of the 5.1 gpt chat api.

gpt 5.1 reasoning logic

The gpt 5.1 chat api introduces System 2 reasoning, allowing the gpt model to verify steps internally before responding, reducing logical errors in math and physics via the api.

Native Multimodal api

This api handles native image, audio, and 5-minute video files directly. Use the gpt 5.1 chat api to perform motion tracking and scene description without complex preprocessing.

Agentic Loop Stability

Optimized for autonomous workflows, the gpt 5.1 chat api maintains state consistency over 50+ tool-calling turns, ensuring stable gpt performance for complex agentic operations.

api Codebase Refactoring

Leverage the gpt 5.1 chat api for repository-scale coding. This gpt model understands deep inheritance and cross-file dependencies across massive 200k token source code blocks.

Related Models
All Models
ModelInput → Output
GPT 5.1 Chat LatestCurrent
—$1.00 / $8.00 per 1M$0.10 / $0.10 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Grok 4.6
500K$1.20 / $3.60 per 1M— / $0.30 per 1M
Input: TextInput: Image
Output: Text
Qwen3.8 Max
1M$1.80 / $5.40 per 1M$2.25 / $0.23 per 1M
Input: TextInput: ImageInput: VideoInput: Document
Output: Text
Claude Opus 5
1M$4.00 / $20.00 per 1M$5.00 / $0.40 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Gemini 3.6 Flash
1.05M$0.90 / $4.50 per 1M$0.09 / $0.09 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Gemini 3.5 Flash Lite
1.05M$0.18 / $1.50 per 1M$0.02 / $0.02 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Kimi K3
1.05M$2.70 / $13.50 per 1M$0.27 / $0.27 per 1M
Input: TextInput: ImageInput: Document
Output: Text
GPT 5.6 Luna
1.05M$0.16 / $0.96 per 1M$0.20 / $0.02 per 1M
Input: TextInput: ImageInput: Document
Output: Text
GPT 5.6 Terra
1.05M$1.60 / $9.60 per 1M$2.00 / $0.16 per 1M
Input: TextInput: ImageInput: Document
Output: Text
GPT 5.6 Sol
1.05M$4.00 / $24.00 per 1M$5.00 / $0.40 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Grok 4.5
500K$1.20 / $3.60 per 1M$0.30 / $0.30 per 1M
Input: TextInput: Image
Output: Text
Claude Sonnet 5
1M$1.60 / $8.00 per 1M$2.00 / $0.16 per 1M
Input: TextInput: Document
Output: Text
Minimax M3
1.05M$0.48 / $0.96 per 1M$0.10 / $0.10 per 1M
Input: TextInput: ImageInput: Document
Output: Text
GLM 5.2
1.05M$1.26 / $3.96 per 1M$0.23 / $0.23 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Claude Fable 5
1M$8.00 / $40.00 per 1M$10.00 / $0.80 per 1M
Input: TextInput: Document
Output: Text
Qwen3.7 Max
1M$0.36 / $1.44 per 1M$0.07 / $0.07 per 1M
Input: TextInput: Document
Output: Text
Gemini 3.5 Flash
1.05M$0.90 / $5.40 per 1M$0.09 / $0.09 per 1M
Input: TextInput: ImageInput: Document
Output: Text
DeepSeek v4 Flash
—1.05M$0.14 / $0.28 per 1M— / $0.0028 per 1M
Input: Text
Output: Text
DeepSeek v4 Pro
1.05M$1.04 / $2.09 per 1M$0.0087 / $0.0087 per 1M
Input: Text
Output: Text
Grok 4.3
1M$0.75 / $1.50 per 1M$0.12 / $0.12 per 1M
Input: TextInput: Image
Output: Text
GPT 5.4 Pro
1.05M$24.00 / $144.00 per 1M—
Input: TextInput: ImageInput: Document
Output: Text
GPT 5.5 Pro
1.05M$24.00 / $144.00 per 1M—
Input: TextInput: ImageInput: Document
Output: Text
GPT 5.5
1.05M$4.00 / $24.00 per 1M$0.40 / $0.40 per 1M
Input: TextInput: ImageInput: Document
Output: Text
Kimi K2.6
262K$0.85 / $3.60 per 1M$0.14 / $0.14 per 1M
Input: TextInput: Document
Output: Text
GLM 5.1
205K$1.26 / $3.96 per 1M$0.23 / $0.23 per 1M
Input: TextInput: Document
Output: Text
GLM 5 Turbo
203K$1.08 / $3.60 per 1M$0.22 / $0.22 per 1M
Input: TextInput: Document
Output: Text
DeepSeek v3.2
164K$0.17 / $0.25 per 1M$0.02 / $0.02 per 1M
Input: Text
Output: Text
Minimax M2.5
205K$0.24 / $0.96 per 1M$0.30 / $0.02 per 1M
Input: TextInput: Document
Output: Text
Kimi K2.5
262K$0.54 / $2.70 per 1M$0.09 / $0.09 per 1M
Input: TextInput: Document
Output: Text
Qwen Turbo
—$0.04 / $0.18 per 1M$0.009 / $0.009 per 1M
Input: Text
Output: Text
Doubao Seed 1.6 Thinking 250715
262K$0.10 / $0.97 per 1M—
Input: TextInput: Image
Output: Text
Doubao Seed 1.6 Thinking 250615
262K$0.10 / $0.97 per 1M—
Input: TextInput: Image
Output: Text
Doubao Seed 1.6 Flash 250615
262K$0.02 / $0.18 per 1M—
Input: TextInput: Image
Output: Text

gpt 5.1 chat api Common Questions

Find answers regarding gpt performance, api costs, and 5.1 chat capabilities.

How does the gpt 5.1 chat api differ from gpt-4o?

The gpt 5.1 chat api introduces native System 2 reasoning, significantly reducing logical fallacies in complex tasks. While gpt-4o is excellent for fast chat, the 5.1 api excels in multi-step planning and architectural coding. Additionally, the 5.1 gpt version supports a massive 256k context window and native video ingestion, features not fully realized in previous gpt models available through our unified api.

What is the reasoning_effort parameter in this api?

Specific to the gpt 5.1 chat api, reasoning_effort (low, medium, high) controls how much compute the gpt model spends on internal Chain of Thought verification. A higher setting improves accuracy for math and code but increases api latency and cost. This allows developers to tune the gpt performance based on the specific needs of their chat or automation application using our 5.1 endpoints.

Is data sent to the gpt 5.1 chat api used for training?

No. Use of the gpt 5.1 chat api on our platform is governed by strict privacy standards. Neither GPTProto nor OpenAI uses data submitted via this api to train foundation models. This ensures that your proprietary gpt prompts and sensitive business data remain confidential while using the latest 5.1 gpt chat capabilities for your professional projects.

How do I migrate my existing app to the 5.1 api?

Migrating to the gpt 5.1 chat api is straightforward. You simply update your model string to gpt-5.1-chat-latest within your api request. Most parameters remain backward compatible with previous gpt versions, though we recommend testing your chat prompts with the new reasoning_effort setting to find the optimal balance for your 5.1 api implementation and budget.

What are the rate limits for the gpt 5.1 chat api?

The gpt 5.1 chat api starts with a default limit of 5,000 RPM and 2M TPM. For enterprise scale, we can scale your gpt access up to 50M TPM. Our api also includes a unique Queue header to automatically handle 429 errors, ensuring your gpt chat applications maintain high availability even during peak usage of the 5.1 model reasoning engines.

Can I use structured JSON with the gpt 5.1 chat api?

Yes, the gpt 5.1 chat api features an enhanced JSON mode. By setting the response_format to json_object, the gpt model guarantees that outputs strictly follow your provided schema. This api capability is essential for developers building automated gpt workflows that require reliable data parsing from complex chat interactions or deep document analysis using 5.1 logic.