o3 is OpenAI’s premier reasoning model, built for elite STEM tasks and advanced coding. With 200k context and high-effort logical thinking, o3 sets new benchmarks in math and complex problem-solving for developers on GPTProto.com.

Modalities

Context

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": "o3",
    "messages": [
      {
        "role": "user",
        "content": "Hello"
      }
    ]
  }'

O3 pricing

Chat, coding agents & document work. Priced per 1M tokens — input, cached input and output are billed separately. GPTProto is 10% below official rates.

Your usage

Model

OpenAI · ≈ 148M tokens/mo (48M cached)

Monthly volume

OpenRouter

List + 5.5% credit fee

$261.64

per month

Input (non-cached)$67.52

Cache read$25.32

Output$168.80

OpenAI

Direct from OpenAI (list price)

$248

per month

Input (non-cached)$64

Cache read$24

Output$160

BEST VALUE

GPTProto

10% off official

$223.20

per month

After discount$223.20

Effective$223.20

Monthly cost by source

OpenRouter

$261.64

OpenAI

$248

GPTProto

$223.20

Save $24.80 / month

on GPTProto vs OpenAI (−10%)

Annual savings ≈ $297.60 · pay as you go

OpenRouter costs include its ~5.5% credit purchase fee. GPTProto applies a per-model discount (10–30% off) and your bonus credits are also spent at discounted rates — savings compound. Estimates assume a 60% cache hit rate.

Related Models

All Models

Current

byOpenAI200K context$1.8/M input$7.2/M output

DeepSeek Flash

byDeepSeek$0.3/M input$1.2/M output

Hy4 Preview

byHunyuan1.05M context$0.7923/M input$2.376/M output

GPT 6 Astra

byOpenAI1.05M context$8/M input$40/M output

Gemini 3.8 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Claude Fable 5.1

byClaude1M context$9/M input$45/M output

Qwen3.8 Max 0902

byQwen1M context$1.8/M input$5.4/M output

GLM 5.3 Flash

byZ-AI1.31M context$0.15/M input$0.5/M output

DeepSeek v4 Flash Vision Exp

byDeepSeek1.05M context$0.3/M input$1.2/M output

GLM 5.3

byZ-AI1.31M context$1.26/M input$3.96/M output

Gemini 3.7 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Grok 4.6

byGrok500K context$1.2/M input$3.6/M output

Qwen3.8 Max

byQwen1M context$1.8/M input$5.4/M output

Claude Opus 5

byClaude1M context$4.5/M input$22.5/M output

Gemini 3.6 Flash

byGoogle1.05M context$0.9/M input$4.5/M output

Kimi K3

byMoonshotAI1.05M context$2.7/M input$13.5/M output

GPT 5.6 Luna

byOpenAI1.05M context$0.16/M input$0.96/M output

GPT 5.6 Terra

byOpenAI1.05M context$1.6/M input$9.6/M output

GPT 5.6 Sol

byOpenAI1.05M context$3.2/M input$16/M output

Grok 4.5

byGrok500K context$1.2/M input$3.6/M output

Claude Sonnet 5

byClaude1M context$1.8/M input$9/M output

Minimax M3

byMiniMax1.05M context$0.48/M input$0.96/M output

GLM 5.2

byZ-AI1.05M context$1.26/M input$3.96/M output

GPT 5.1 Chat Latest

byOpenAI$1/M input$8/M output

Qwen3.7 Max

byQwen1M context$0.36/M input$1.44/M output

DeepSeek v4 Flash

byDeepSeek1.05M context$0.3/M input$1.2/M output

Grok 4.3

byGrok1M context$0.75/M input$1.5/M output

GPT 5.4 Pro

byOpenAI1.05M context$24/M input$144/M output

Kimi K2.6

byMoonshotAI262K context$0.855/M input$3.6/M output

Minimax M2.5

byMiniMax205K context$0.24/M input$0.96/M output

Kimi K2.5

byMoonshotAI262K context$0.54/M input$2.7/M output

Doubao Seed 1.6 Thinking (Build 250715)

byBytedance262K context$0.0971/M input$0.9714/M output

Doubao Seed 1.6 Thinking (Build 250615)

byBytedance262K context$0.0971/M input$0.9714/M output

Doubao Seed 1.6 Flash (Build 250615)

byBytedance262K context$0.0182/M input$0.1821/M output

Model					Input → Output
O3Current $		200K	$1.80 / $7.20 per 1M	$0.45 / $0.45 per 1M	Input: TextInput: ImageInput: Document Output: Text
DeepSeek Flash $	—	—	$0.30 / $1.20 per 1M	— / $0.006 per 1M	Input: TextInput: Image Output: Text
Hy4 Preview $		1.05M	$0.79 / $2.38 per 1M	— / $0.04 per 1M	Input: Text Output: Text
GPT 6 Astra $		1.05M	$8.00 / $40.00 per 1M	$10.00 / $0.80 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.8 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 per 1M	Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text
Claude Fable 5.1 $		1M	$9.00 / $45.00 per 1M	$11.25 / $0.23 per 1M	Input: TextInput: ImageInput: Document Output: Text
Qwen3.8 Max 0902 $		1M	$1.80 / $5.40 per 1M	$2.25 / $0.23 per 1M	Input: TextInput: ImageInput: VideoInput: DocumentInput: Audio Output: Text
GLM 5.3 Flash $	—	1.31M	$0.15 / $0.50 per 1M	— / $0.03 per 1M	Input: TextInput: ImageInput: VideoInput: Document Output: Text
DeepSeek v4 Flash Vision Exp $	—	1.05M	$0.30 / $1.20 per 1M	— / $0.006 per 1M	Input: TextInput: Image Output: Text
GLM 5.3 $		1.31M	$1.26 / $3.96 per 1M	— / $0.23 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.7 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 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	$4.50 / $22.50 per 1M	$5.63 / $0.45 per 1M	Input: TextInput: ImageInput: Document Output: Text
Gemini 3.6 Flash $		1.05M	$0.90 / $4.50 per 1M	$0.60 / $0.09 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	$3.20 / $16.00 per 1M	$4.00 / $0.32 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	$1.80 / $9.00 per 1M	$2.25 / $0.18 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
GPT 5.1 Chat Latest $		—	$1.00 / $8.00 per 1M	$0.10 / $0.10 per 1M	Input: TextInput: ImageInput: Document Output: Text
Qwen3.7 Max $		1M	$0.36 / $1.44 per 1M	$0.07 / $0.07 per 1M	Input: TextInput: Document Output: Text
DeepSeek v4 Flash $	—	1.05M	$0.30 / $1.20 per 1M	— / $0.006 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
Kimi K2.6 $		262K	$0.85 / $3.60 per 1M	$0.14 / $0.14 per 1M	Input: TextInput: Document 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
Doubao Seed 1.6 Thinking (Build 250715) $		262K	$0.10 / $0.97 per 1M	—	Input: TextInput: Image Output: Text
Doubao Seed 1.6 Thinking (Build 250615) $		262K	$0.10 / $0.97 per 1M	—	Input: TextInput: Image Output: Text
Doubao Seed 1.6 Flash (Build 250615) $		262K	$0.02 / $0.18 per 1M	—	Input: TextInput: Image Output: Text

o3 Standout Capabilities

Explore the core strengths that make o3 the most advanced reasoning model for STEM, coding, and logical planning on GPTProto.com.

Elite STEM Reasoning

o3 dominates math and science benchmarks, scoring 90.2% on the AIME 2024 and outperforming human experts in complex logic.

Grandmaster Coding Power

Rated at ~2727 ELO on Codeforces, o3 is more capable than 99% of human programmers for refactoring and testing applications.

Configurable Logic Effort

Balance speed and depth with the reasoning_effort parameter, tailoring o3 to your specific latency and cost needs.

Agentic Planning Precision

o3 offers high reliability in multi-step tool orchestration, significantly reducing failures in complex software environments.

OpenAI o3 Frequently Asked Questions

Find answers to technical questions about o3, including API integration, reasoning effort settings, and performance benchmarks for OpenAI's advanced model.

What makes o3 different from the o1 series?

o3 is a generational step up in speed and cognitive depth. While o1 was a breakthrough in reasoning, o3 achieves significantly higher benchmarks, such as 90.2% on AIME 2024. It provides deeper logical planning and faster execution for complex STEM tasks, making it the preferred choice for frontier-level engineering and scientific simulations.

How do I control o3 reasoning time and cost?

You can use the reasoning_effort parameter with values of low, medium, or high. This allows you to balance latency against logical depth. High effort is best for difficult math or competitive coding, while low effort reduces the model's thinking time and overall costs for simpler logical flows that still require o3's architectural precision.

Can o3 handle images and tool calling?

Yes, o3 is a multimodal model. It can process image inputs and generate text or code outputs based on visual data. It also supports function calling and structured JSON mode, making it an excellent choice for agentic workflows that require precise tool orchestration and multi-step planning without the high failure rates seen in earlier models.

What are the token limits for o3 on GPTProto.com?

o3 features a massive 200,000-token context window. It can generate up to 100,000 output tokens, which includes the internal, hidden reasoning tokens used for its chain-of-thought process. This large capacity allows for processing very large datasets or complex codebases in a single request without losing track of intricate logical threads.

Is data sent to o3 used for training?

No. When you access o3 through GPTProto.com's API aggregation platform, your data is sent to enterprise endpoints. Neither we nor OpenAI use this data to train foundation models, ensuring your proprietary code, research data, and sensitive financial logs remain secure and private according to enterprise-grade compliance standards.

Why did my o3 request return a 400 error?

A 400 error often occurs if the max_completion_tokens parameter is set too low. Since o3 requires a significant portion of its output tokens for its internal reasoning process (hidden chain-of-thought), you must provide a large enough budget for both the intensive thinking phase and the final response to avoid premature termination of the request.