How do I use GPT-4o through YepAPI?

Sign up for a free API key, then send requests to the /v1/ai/chat endpoint.

OpenAIText Generation/v1/ai/chat

GPT-4o

Access GPT-4o through one API key. Flagship reasoning and multimodal capabilities.

OpenAI's flagship multimodal model. Strong reasoning, vision capabilities, and broad general knowledge.

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2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see GPT-4o respond in real time.

POST/v1/ai/chatopenai/gpt-4o

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

Context Window

128K tokens

Max Output

16K tokens

Input Price

$3.50 / 1M tokens

Output Price

$14.00 / 1M tokens

Strengths

✓

Strong reasoning

Handles multi-step problem solving, analysis, and instruction-following well across general domains, backed by a 128K-token context window.

✓

Vision & multimodal

Accepts image inputs alongside text, so it can describe, analyze, and reason over screenshots, charts, and photos in the same request.

✓

Code generation

Writes, explains, and debugs code across mainstream languages, returning up to 16,384 output tokens per call for substantial functions or files.

✓

General knowledge

Broad world knowledge makes it a dependable default for chat, drafting, and Q&A where you want one flagship model rather than a specialist.

Quick start

Copy this snippet and start making calls with GPT-4o.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "openai/gpt-4o",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

Why use GPT-4o through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

GPT-4o API — pricing, context window & access

GPT-4o is OpenAI's flagship multimodal model, combining strong text reasoning with native vision in a single endpoint. It offers a 128K-token context window and up to 16,384 output tokens per response.

With YepAPI you reach GPT-4o through one OpenAI-compatible key — the same key that also covers GPT-4o Mini, Claude, Gemini, and the SEO, SERP and scraping APIs.

What is GPT-4o?

GPT-4o is OpenAI's flagship multimodal model — the 'o' is for omni, reflecting its ability to process text and images in one model. It was designed as a general-purpose workhorse with strong reasoning, broad world knowledge, and native vision, sitting above GPT-4o Mini in OpenAI's lineup. It's the model teams reach for when a single endpoint needs to handle chat, analysis, coding, and image understanding without juggling specialists. With a 128K context window it comfortably reads long documents while still answering quickly.

Build with GPT-4o via YepAPI

YepAPI serves GPT-4o on the OpenAI-compatible /v1/ai/chat endpoint. Set your base URL, add your key, and use the model string gpt-4o — text and image inputs both go through the same chat-completions shape you already know. Moving between GPT-4o, GPT-4o Mini, Claude Sonnet, or Gemini Pro is just changing that one string. The same key also reaches search and scraping endpoints, so multimodal apps and data pipelines share one account.

GPT-4o API pricing — $3.50 / 1M input, $14.00 / 1M output

GPT-4o costs $3.50 per 1M input tokens and $14.00 per 1M output tokens through YepAPI. That mid-tier flagship pricing buys vision plus strong reasoning in one model. Image inputs are tokenized alongside text, so vision requests draw on the same input rate. You pay only for tokens used, making it practical to reserve GPT-4o for tasks that genuinely need multimodal or higher-quality reasoning while routing simpler work to cheaper models.

GPT-4o for vision & multimodal tasks

GPT-4o's standout capability is native vision. Send a screenshot, chart, receipt, or diagram in the same request as your prompt and it reasons over the image directly — extracting data, describing UI, or answering questions about what it sees. Combined with its 128K context and solid coding, it suits agents and tools that mix documents, images, and instructions in one call rather than stitching separate OCR and language services together.

Try GPT-4o free

Every new YepAPI account includes $5 in free credit, no card required. That's enough to test GPT-4o's vision and reasoning on your own prompts and images first. Create an account, copy your key, and start calling GPT-4o right away.

Start generating in 30 seconds

$5 free credit on signup. No credit card required. Pay per call.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

OpenAI's flagship multimodal model. Strong reasoning, vision capabilities, and broad general knowledge.

Input tokens cost $3.50 per 1M tokens and output tokens cost $14.00 per 1M tokens through YepAPI. No monthly minimums — you only pay for what you use.

GPT-4o supports a 128K token context window with up to 16K output tokens per request.